What this read moved
51–75 of 209This capture is too large to show at once. Changes 51-75 of 209 are below, significant first; the rest are on the following screens.
api/beta/memory_stores/archive Changed · +7 / -1 lines
from line 16
1616
1717 - `string`
1818
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2020
2121 - `"message-batches-2024-09-24"`
2222
from line 99
9999 - `"thinking-display-updates-2026-08-18"`
100100
101101 - `"ce-user-management-2026-07-13"`
102
103 - `"mid-conversation-output-config-2026-07-01"`
104
105 - `"thinking-binding-controls-2026-08-01"`
106
107 - `"mid-conversation-system-clear-at-2026-08-21"`
102108
103109## Returns
104110
api/beta/memory_stores/create Changed · +7 / -1 lines
from line 12
1212
1313 - `string`
1414
15 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
15 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
1616
1717 - `"message-batches-2024-09-24"`
1818
from line 95
9595 - `"thinking-display-updates-2026-08-18"`
9696
9797 - `"ce-user-management-2026-07-13"`
98
99 - `"mid-conversation-output-config-2026-07-01"`
100
101 - `"thinking-binding-controls-2026-08-01"`
102
103 - `"mid-conversation-system-clear-at-2026-08-21"`
98104
99105## Body parameters
100106
api/beta/memory_stores/delete Changed · +7 / -1 lines
from line 16
1616
1717 - `string`
1818
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2020
2121 - `"message-batches-2024-09-24"`
2222
from line 99
9999 - `"thinking-display-updates-2026-08-18"`
100100
101101 - `"ce-user-management-2026-07-13"`
102
103 - `"mid-conversation-output-config-2026-07-01"`
104
105 - `"thinking-binding-controls-2026-08-01"`
106
107 - `"mid-conversation-system-clear-at-2026-08-21"`
102108
103109## Returns
104110
api/beta/memory_stores/list Changed · +7 / -1 lines
from line 40
4040
4141 - `string`
4242
43 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
43 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
4444
4545 - `"message-batches-2024-09-24"`
4646
from line 123
123123 - `"thinking-display-updates-2026-08-18"`
124124
125125 - `"ce-user-management-2026-07-13"`
126
127 - `"mid-conversation-output-config-2026-07-01"`
128
129 - `"thinking-binding-controls-2026-08-01"`
130
131 - `"mid-conversation-system-clear-at-2026-08-21"`
126132
127133## Returns
128134
api/beta/memory_stores/memories Changed · +37 / -7 lines
from line 28
2828
2929 - `string`
3030
31 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
31 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
3232
3333 - `"message-batches-2024-09-24"`
3434
from line 112
112112
113113 - `"ce-user-management-2026-07-13"`
114114
115 - `"mid-conversation-output-config-2026-07-01"`
116
117 - `"thinking-binding-controls-2026-08-01"`
118
119 - `"mid-conversation-system-clear-at-2026-08-21"`
120
115121### Body parameters
116122
117123- `content: string or null`
from line 126
120126
121127- `path: string`
122128
123 Hierarchical path for the new memory, e.g. `/projects/foo/notes.md`. Must start with `/`, contain at least one non-empty segment, and be at most 1,024 bytes. Must not contain empty segments, `.` or `..` segments, control or format characters, and must be NFC-normalized. Paths are case-sensitive.
129 Hierarchical path for the new memory, e.g. `/projects/foo/notes.md`. Must start with `/`, contain at least one non-empty segment, and be at most 1,024 bytes. Must not contain empty segments, `.` or `..` segments, control or format characters, or the Unicode line and paragraph separators (U+2028, U+2029), and must be NFC-normalized. Paths are case-sensitive.
124130
125131 minLength: 2, maxLength: 1024
126132
from line 259
253259
254260 - `string`
255261
256 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
262 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
257263
258264 - `"message-batches-2024-09-24"`
259265
from line 343
337343
338344 - `"ce-user-management-2026-07-13"`
339345
346 - `"mid-conversation-output-config-2026-07-01"`
347
348 - `"thinking-binding-controls-2026-08-01"`
349
350 - `"mid-conversation-system-clear-at-2026-08-21"`
351
340352### Returns
341353
342354- `data: optional array of BetaManagedAgentsMemoryListItem`
from line 478
466478
467479 - `string`
468480
469 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
481 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
470482
471483 - `"message-batches-2024-09-24"`
472484
from line 562
550562
551563 - `"ce-user-management-2026-07-13"`
552564
565 - `"mid-conversation-output-config-2026-07-01"`
566
567 - `"thinking-binding-controls-2026-08-01"`
568
569 - `"mid-conversation-system-clear-at-2026-08-21"`
570
553571### Returns
554572
555573- `BetaManagedAgentsMemory object`
from line 674
656674
657675 - `string`
658676
659 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
677 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
660678
661679 - `"message-batches-2024-09-24"`
662680
from line 758
740758
741759 - `"ce-user-management-2026-07-13"`
742760
761 - `"mid-conversation-output-config-2026-07-01"`
762
763 - `"thinking-binding-controls-2026-08-01"`
764
765 - `"mid-conversation-system-clear-at-2026-08-21"`
766
743767### Body parameters
744768
745769- `content: optional string or null`
from line 772
748772
749773- `path: optional string or null`
750774
751 New path for the memory (a rename). Must start with `/`, contain at least one non-empty segment, and be at most 1,024 bytes. Must not contain empty segments, `.` or `..` segments, control or format characters, and must be NFC-normalized. Paths are case-sensitive. The memory's `id` is preserved across renames. Omit to leave the path unchanged.
775 New path for the memory (a rename). Must start with `/`, contain at least one non-empty segment, and be at most 1,024 bytes. Must not contain empty segments, `.` or `..` segments, control or format characters, or the Unicode line and paragraph separators (U+2028, U+2029), and must be NFC-normalized. Paths are case-sensitive. The memory's `id` is preserved across renames. Omit to leave the path unchanged.
752776
753777 minLength: 2, maxLength: 1024
754778
from line 890
866890
867891 - `string`
868892
869 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
893 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
870894
871895 - `"message-batches-2024-09-24"`
872896
from line 973
949973 - `"thinking-display-updates-2026-08-18"`
950974
951975 - `"ce-user-management-2026-07-13"`
976
977 - `"mid-conversation-output-config-2026-07-01"`
978
979 - `"thinking-binding-controls-2026-08-01"`
980
981 - `"mid-conversation-system-clear-at-2026-08-21"`
952982
953983### Returns
954984
api/beta/memory_stores/memories/create Changed · +8 / -2 lines
from line 26
2626
2727 - `string`
2828
29 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
29 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
3030
3131 - `"message-batches-2024-09-24"`
3232
from line 110
110110
111111 - `"ce-user-management-2026-07-13"`
112112
113 - `"mid-conversation-output-config-2026-07-01"`
114
115 - `"thinking-binding-controls-2026-08-01"`
116
117 - `"mid-conversation-system-clear-at-2026-08-21"`
118
113119## Body parameters
114120
115121- `content: string or null`
from line 124
118124
119125- `path: string`
120126
121 Hierarchical path for the new memory, e.g. `/projects/foo/notes.md`. Must start with `/`, contain at least one non-empty segment, and be at most 1,024 bytes. Must not contain empty segments, `.` or `..` segments, control or format characters, and must be NFC-normalized. Paths are case-sensitive.
127 Hierarchical path for the new memory, e.g. `/projects/foo/notes.md`. Must start with `/`, contain at least one non-empty segment, and be at most 1,024 bytes. Must not contain empty segments, `.` or `..` segments, control or format characters, or the Unicode line and paragraph separators (U+2028, U+2029), and must be NFC-normalized. Paths are case-sensitive.
122128
123129 minLength: 2, maxLength: 1024
124130
api/beta/memory_stores/memories/delete Changed · +7 / -1 lines
from line 24
2424
2525 - `string`
2626
27 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
27 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2828
2929 - `"message-batches-2024-09-24"`
3030
from line 107
107107 - `"thinking-display-updates-2026-08-18"`
108108
109109 - `"ce-user-management-2026-07-13"`
110
111 - `"mid-conversation-output-config-2026-07-01"`
112
113 - `"thinking-binding-controls-2026-08-01"`
114
115 - `"mid-conversation-system-clear-at-2026-08-21"`
110116
111117## Returns
112118
api/beta/memory_stores/memories/list Changed · +7 / -1 lines
from line 46
4646
4747 - `string`
4848
49 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
49 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
5050
5151 - `"message-batches-2024-09-24"`
5252
from line 129
129129 - `"thinking-display-updates-2026-08-18"`
130130
131131 - `"ce-user-management-2026-07-13"`
132
133 - `"mid-conversation-output-config-2026-07-01"`
134
135 - `"thinking-binding-controls-2026-08-01"`
136
137 - `"mid-conversation-system-clear-at-2026-08-21"`
132138
133139## Returns
134140
api/beta/memory_stores/memories/retrieve Changed · +7 / -1 lines
from line 28
2828
2929 - `string`
3030
31 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
31 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
3232
3333 - `"message-batches-2024-09-24"`
3434
from line 111
111111 - `"thinking-display-updates-2026-08-18"`
112112
113113 - `"ce-user-management-2026-07-13"`
114
115 - `"mid-conversation-output-config-2026-07-01"`
116
117 - `"thinking-binding-controls-2026-08-01"`
118
119 - `"mid-conversation-system-clear-at-2026-08-21"`
114120
115121## Returns
116122
api/beta/memory_stores/memories/update Changed · +8 / -2 lines
from line 28
2828
2929 - `string`
3030
31 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
31 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
3232
3333 - `"message-batches-2024-09-24"`
3434
from line 112
112112
113113 - `"ce-user-management-2026-07-13"`
114114
115 - `"mid-conversation-output-config-2026-07-01"`
116
117 - `"thinking-binding-controls-2026-08-01"`
118
119 - `"mid-conversation-system-clear-at-2026-08-21"`
120
115121## Body parameters
116122
117123- `content: optional string or null`
from line 126
120126
121127- `path: optional string or null`
122128
123 New path for the memory (a rename). Must start with `/`, contain at least one non-empty segment, and be at most 1,024 bytes. Must not contain empty segments, `.` or `..` segments, control or format characters, and must be NFC-normalized. Paths are case-sensitive. The memory's `id` is preserved across renames. Omit to leave the path unchanged.
129 New path for the memory (a rename). Must start with `/`, contain at least one non-empty segment, and be at most 1,024 bytes. Must not contain empty segments, `.` or `..` segments, control or format characters, or the Unicode line and paragraph separators (U+2028, U+2029), and must be NFC-normalized. Paths are case-sensitive. The memory's `id` is preserved across renames. Omit to leave the path unchanged.
124130
125131 minLength: 2, maxLength: 1024
126132
api/beta/memory_stores/memory_versions Changed · +21 / -3 lines
from line 76
7676
7777 - `string`
7878
79 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
79 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
8080
8181 - `"message-batches-2024-09-24"`
8282
from line 160
160160
161161 - `"ce-user-management-2026-07-13"`
162162
163 - `"mid-conversation-output-config-2026-07-01"`
164
165 - `"thinking-binding-controls-2026-08-01"`
166
167 - `"mid-conversation-system-clear-at-2026-08-21"`
168
163169### Returns
164170
165171- `data: optional array of BetaManagedAgentsMemoryVersion`
from line 356
350356
351357 - `string`
352358
353 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
359 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
354360
355361 - `"message-batches-2024-09-24"`
356362
from line 440
434440
435441 - `"ce-user-management-2026-07-13"`
436442
443 - `"mid-conversation-output-config-2026-07-01"`
444
445 - `"thinking-binding-controls-2026-08-01"`
446
447 - `"mid-conversation-system-clear-at-2026-08-21"`
448
437449### Returns
438450
439451- `BetaManagedAgentsMemoryVersion object`
from line 617
605617
606618 - `string`
607619
608 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
620 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
609621
610622 - `"message-batches-2024-09-24"`
611623
from line 700
688700 - `"thinking-display-updates-2026-08-18"`
689701
690702 - `"ce-user-management-2026-07-13"`
703
704 - `"mid-conversation-output-config-2026-07-01"`
705
706 - `"thinking-binding-controls-2026-08-01"`
707
708 - `"mid-conversation-system-clear-at-2026-08-21"`
691709
692710### Returns
693711
api/beta/memory_stores/memory_versions/list Changed · +7 / -1 lines
from line 74
7474
7575 - `string`
7676
77 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
77 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
7878
7979 - `"message-batches-2024-09-24"`
8080
from line 157
157157 - `"thinking-display-updates-2026-08-18"`
158158
159159 - `"ce-user-management-2026-07-13"`
160
161 - `"mid-conversation-output-config-2026-07-01"`
162
163 - `"thinking-binding-controls-2026-08-01"`
164
165 - `"mid-conversation-system-clear-at-2026-08-21"`
160166
161167## Returns
162168
api/beta/memory_stores/memory_versions/redact Changed · +7 / -1 lines
from line 18
1818
1919 - `string`
2020
21 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
21 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2222
2323 - `"message-batches-2024-09-24"`
2424
from line 101
101101 - `"thinking-display-updates-2026-08-18"`
102102
103103 - `"ce-user-management-2026-07-13"`
104
105 - `"mid-conversation-output-config-2026-07-01"`
106
107 - `"thinking-binding-controls-2026-08-01"`
108
109 - `"mid-conversation-system-clear-at-2026-08-21"`
104110
105111## Returns
106112
api/beta/memory_stores/memory_versions/retrieve Changed · +7 / -1 lines
from line 28
2828
2929 - `string`
3030
31 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
31 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
3232
3333 - `"message-batches-2024-09-24"`
3434
from line 111
111111 - `"thinking-display-updates-2026-08-18"`
112112
113113 - `"ce-user-management-2026-07-13"`
114
115 - `"mid-conversation-output-config-2026-07-01"`
116
117 - `"thinking-binding-controls-2026-08-01"`
118
119 - `"mid-conversation-system-clear-at-2026-08-21"`
114120
115121## Returns
116122
api/beta/memory_stores/retrieve Changed · +7 / -1 lines
from line 16
1616
1717 - `string`
1818
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2020
2121 - `"message-batches-2024-09-24"`
2222
from line 99
9999 - `"thinking-display-updates-2026-08-18"`
100100
101101 - `"ce-user-management-2026-07-13"`
102
103 - `"mid-conversation-output-config-2026-07-01"`
104
105 - `"thinking-binding-controls-2026-08-01"`
106
107 - `"mid-conversation-system-clear-at-2026-08-21"`
102108
103109## Returns
104110
api/beta/memory_stores/update Changed · +7 / -1 lines
from line 16
1616
1717 - `string`
1818
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2020
2121 - `"message-batches-2024-09-24"`
2222
from line 99
9999 - `"thinking-display-updates-2026-08-18"`
100100
101101 - `"ce-user-management-2026-07-13"`
102
103 - `"mid-conversation-output-config-2026-07-01"`
104
105 - `"thinking-binding-controls-2026-08-01"`
106
107 - `"mid-conversation-system-clear-at-2026-08-21"`
102108
103109## Body parameters
104110
api/beta/messages Changed · +1122 / -137 lines
### Beta System Message Output Config ### Beta Thinking Block Binding ### Beta Thinking Dropped Input Transformation ### Beta Thinking Prefix Mismatch Behavior
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from line 18
1818
1919 - `string`
2020
21 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
21 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2222
2323 - `"message-batches-2024-09-24"`
2424
from line 101
101101 - `"thinking-display-updates-2026-08-18"`
102102
103103 - `"ce-user-management-2026-07-13"`
104
105 - `"mid-conversation-output-config-2026-07-01"`
106
107 - `"thinking-binding-controls-2026-08-01"`
108
109 - `"mid-conversation-system-clear-at-2026-08-21"`
104110
105111- `"anthropic-user-profile-id": optional string`
106112
from line 1400
13941400
13951401 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
13961402
1397 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
1403 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
13981404
13991405 The model that will complete your prompt.
14001406
14011407 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
14021408
1409 - `"claude-fable-5-1"`
1410
1411 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
1412
1413 - `"claude-mythos-5-1"`
1414
1415 Our most capable model for cybersecurity and biology research, available through trusted access programs
1416
14031417 - `"claude-sonnet-5"`
14041418
14051419 High-performance model for coding and agents
from line 1493
14791493 - `"assistant"`
14801494
14811495 - `"system"`
1496
1497 - `clear_at: optional "next_user_message" or "never" or null`
1498
1499 How long this system message's text stays in front of the model. `"never"` (the default) renders it on every request that includes it. `"next_user_message"` renders it only for the user turn it follows: once a later `role: "user"` message exists in `messages` the message stays in the array (send it unchanged) but is no longer shown to the model. Only permitted on `role: "system"` messages.
1500
1501 - `"next_user_message"`
1502
1503 - `"never"`
1504
1505 - `output_config: optional BetaSystemMessageOutputConfig or null`
1506
1507 Per-message output configuration on a role:"system" input message.
1508
1509 Fields here apply per-turn; `format` remains top-level only. An
1510 empty `{}` is accepted on a message that carries content; a message
1511 with neither content nor output_config fields is rejected.
1512
1513 - `effort: optional "low" or "medium" or "high" or 2 more or null`
1514
1515 All possible effort levels.
1516
1517 - `"low"`
1518
1519 - `"medium"`
1520
1521 - `"high"`
1522
1523 - `"xhigh"`
1524
1525 - `"max"`
14821526
14831527- `model: Model`
14841528
from line 1826
17821826
17831827 - `type: "enabled"`
17841828
1829 - `block_binding: optional BetaThinkingBlockBinding or null`
1830
1831 Controls for block binding: what happens when a thinking block this
1832 request sends back fails the conversation check. Every field is optional;
1833 an empty object means every default.
1834
1835 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
1836
1837 What happens when a thinking block in `messages` fails the conversation
1838 check: it was created in a different conversation, or the messages before
1839 it have changed since. `"error"` (the default) fails the request with a
1840 400 error. `"drop_block"` removes the failing blocks and the request
1841 proceeds; the model no longer sees the dropped reasoning.
1842
1843 - `"error"`
1844
1845 - `"drop_block"`
1846
17851847 - `display: optional "summarized" or "omitted" or "updates" or null`
17861848
17871849 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 1861
17991861 - `BetaThinkingConfigAdaptive object`
18001862
18011863 - `type: "adaptive"`
1864
1865 - `block_binding: optional BetaThinkingBlockBinding or null`
1866
1867 Controls for block binding: what happens when a thinking block this
1868 request sends back fails the conversation check. Every field is optional;
1869 an empty object means every default.
18021870
18031871 - `display: optional "summarized" or "omitted" or "updates" or null`
18041872
from line 2369
23012369
23022370 - `type: "browser_toolset_20260801"`
23032371
2304 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2305
2306 - `"direct"`
2307
2308 - `"code_execution_20250825"`
2309
2310 - `"code_execution_20260120"`
2311
2312 - `"code_execution_20260521"`
2313
23142372 - `cache_control: optional BetaCacheControlEphemeral or null`
23152373
23162374 Create a cache control breakpoint at this content block.
from line 2995
29372995
29382996 - `type: "computer_toolset_20260801"`
29392997
2940 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2941
2942 - `"direct"`
2943
2944 - `"code_execution_20250825"`
2945
2946 - `"code_execution_20260120"`
2947
2948 - `"code_execution_20260521"`
2949
29502998 - `cache_control: optional BetaCacheControlEphemeral or null`
29512999
29523000 Create a cache control breakpoint at this content block.
from line 4876
48284876
48294877 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
48304878
4831 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
4879 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
48324880
48334881 The model that will complete your prompt.
48344882
48354883 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
4884
4885 - `"claude-fable-5-1"`
4886
4887 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
4888
4889 - `"claude-mythos-5-1"`
4890
4891 Our most capable model for cybersecurity and biology research, available through trusted access programs
48364892
48374893 - `"claude-sonnet-5"`
48384894
from line 5621
55655621
55665622 - `"fast"`
55675623
5624 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
5625
5626 Changes the API made to the request's input before showing it to the model:
5627 one entry per change, in request order. Today the only entry type is
5628 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
5629 block from the request's `messages` that was removed from the prompt instead
5630 of being shown to the model because it failed a binding check. More entry
5631 types may be added over time; ignore types you do not recognize.
5632
5633 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
5634 every such response from a model that supports extended thinking, as `[]`
5635 when nothing was changed; without the beta, blocks are removed all the same
5636 but nothing is reported. Removed blocks contribute nothing to
5637 `usage.input_tokens`. When streaming, the array is final in `message_start`;
5638 the final `message_delta` event carries it only when a server-side model
5639 fallback happened mid-stream, in which case it holds the serving model's
5640 entries and replaces the one in `message_start`.
5641
5642 - `path: string`
5643
5644 Where the removed block was in your request, as `messages.{i}.content.{j}`:
5645 `i` indexes the `messages` array you sent and `j` that message's `content`
5646 array — the same form error messages use.
5647
5648 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
5649
5650 Which binding check removed the block: `model_binding_mismatch` — it was
5651 created by a model whose reasoning the requested model may not read;
5652 `prefix_binding_mismatch` — the conversation before it differs from the
5653 conversation it was created in (the rest of that turn's consecutive thinking
5654 blocks are removed with it, each with this reason);
5655 `organization_binding_mismatch` — it was created under a different
5656 organization (an Anthropic organization, AWS account or Google Cloud project)
5657 and this organization is not one of its additional organizations;
5658 `end_user_binding_mismatch` — it was created for a different end user, or
5659 was removed by the consumer-organization binding. A block that would fail
5660 several checks reports one reason, in this order of precedence:
5661 `organization_binding_mismatch`, `end_user_binding_mismatch`,
5662 `model_binding_mismatch`, `prefix_binding_mismatch`.
5663
5664 - `"model_binding_mismatch"`
5665
5666 - `"prefix_binding_mismatch"`
5667
5668 - `"organization_binding_mismatch"`
5669
5670 - `"end_user_binding_mismatch"`
5671
5672 - `type: "thinking_dropped"`
5673
5674 Always `thinking_dropped` for this entry type.
5675
5676 default: thinking_dropped
5677
55685678- `BetaRawMessageStreamEvent = BetaRawMessageStartEvent or BetaRawMessageDeltaEvent or BetaRawMessageStopEvent or 3 more`
55695679
55705680 - `BetaRawMessageStartEvent object`
from line 5771
56615771 - `server_tool_use: BetaServerToolUsage or null`
56625772
56635773 The number of server tool requests.
5774
5775 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
5776
5777 Changes the API made to the request's input before showing it to the model:
5778 one entry per change, in request order. Today the only entry type is
5779 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
5780 block from the request's `messages` that was removed from the prompt instead
5781 of being shown to the model because it failed a binding check. More entry
5782 types may be added over time; ignore types you do not recognize.
5783
5784 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
5785 every such response from a model that supports extended thinking, as `[]`
5786 when nothing was changed; without the beta, blocks are removed all the same
5787 but nothing is reported. Removed blocks contribute nothing to
5788 `usage.input_tokens`. When streaming, the array is final in `message_start`;
5789 the final `message_delta` event carries it only when a server-side model
5790 fallback happened mid-stream, in which case it holds the serving model's
5791 entries and replaces the one in `message_start`.
5792
5793 - `path: string`
5794
5795 Where the removed block was in your request, as `messages.{i}.content.{j}`:
5796 `i` indexes the `messages` array you sent and `j` that message's `content`
5797 array — the same form error messages use.
5798
5799 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
5800
5801 Which binding check removed the block: `model_binding_mismatch` — it was
5802 created by a model whose reasoning the requested model may not read;
5803 `prefix_binding_mismatch` — the conversation before it differs from the
5804 conversation it was created in (the rest of that turn's consecutive thinking
5805 blocks are removed with it, each with this reason);
5806 `organization_binding_mismatch` — it was created under a different
5807 organization (an Anthropic organization, AWS account or Google Cloud project)
5808 and this organization is not one of its additional organizations;
5809 `end_user_binding_mismatch` — it was created for a different end user, or
5810 was removed by the consumer-organization binding. A block that would fail
5811 several checks reports one reason, in this order of precedence:
5812 `organization_binding_mismatch`, `end_user_binding_mismatch`,
5813 `model_binding_mismatch`, `prefix_binding_mismatch`.
5814
5815 - `type: "thinking_dropped"`
5816
5817 Always `thinking_dropped` for this entry type.
5818
5819 default: thinking_dropped
56645820
56655821 - `BetaRawMessageStopEvent object`
56665822
from line 6110
59546110 "cache_creation_input_tokens": 0,
59556111 "cache_read_input_tokens": 0,
59566112 "input_tokens": 0,
5957 "model": "claude-sonnet-5",
6113 "model": "claude-fable-5-1",
59586114 "output_tokens": 0,
59596115 "type": "message"
59606116 }
from line 6125
59696125 },
59706126 "service_tier": "standard",
59716127 "speed": "standard"
5972 }
6128 },
6129 "input_transformations": [
6130 {
6131 "path": "path",
6132 "reason": "model_binding_mismatch",
6133 "type": "thinking_dropped"
6134 }
6135 ]
59736136}
59746137```
59756138
from line 6154
59916154
59926155 - `string`
59936156
5994 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
6157 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
59956158
59966159 - `"message-batches-2024-09-24"`
59976160
from line 6237
60746237 - `"thinking-display-updates-2026-08-18"`
60756238
60766239 - `"ce-user-management-2026-07-13"`
6240
6241 - `"mid-conversation-output-config-2026-07-01"`
6242
6243 - `"thinking-binding-controls-2026-08-01"`
6244
6245 - `"mid-conversation-system-clear-at-2026-08-21"`
60776246
60786247- `"anthropic-user-profile-id": optional string`
60796248
from line 7524
73557524
73567525 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
73577526
7358 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
7527 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
73597528
73607529 The model that will complete your prompt.
73617530
73627531 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
73637532
7533 - `"claude-fable-5-1"`
7534
7535 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
7536
7537 - `"claude-mythos-5-1"`
7538
7539 Our most capable model for cybersecurity and biology research, available through trusted access programs
7540
73647541 - `"claude-sonnet-5"`
73657542
73667543 High-performance model for coding and agents
from line 7618
74417618
74427619 - `"system"`
74437620
7621 - `clear_at: optional "next_user_message" or "never" or null`
7622
7623 How long this system message's text stays in front of the model. `"never"` (the default) renders it on every request that includes it. `"next_user_message"` renders it only for the user turn it follows: once a later `role: "user"` message exists in `messages` the message stays in the array (send it unchanged) but is no longer shown to the model. Only permitted on `role: "system"` messages.
7624
7625 - `"next_user_message"`
7626
7627 - `"never"`
7628
7629 - `output_config: optional BetaSystemMessageOutputConfig or null`
7630
7631 Per-message output configuration on a role:"system" input message.
7632
7633 Fields here apply per-turn; `format` remains top-level only. An
7634 empty `{}` is accepted on a message that carries content; a message
7635 with neither content nor output_config fields is rejected.
7636
7637 - `effort: optional "low" or "medium" or "high" or 2 more or null`
7638
7639 All possible effort levels.
7640
7641 - `"low"`
7642
7643 - `"medium"`
7644
7645 - `"high"`
7646
7647 - `"xhigh"`
7648
7649 - `"max"`
7650
74447651- `model: Model`
74457652
74467653 The model that will complete your prompt.
from line 7886
76797886
76807887 - `type: "enabled"`
76817888
7889 - `block_binding: optional BetaThinkingBlockBinding or null`
7890
7891 Controls for block binding: what happens when a thinking block this
7892 request sends back fails the conversation check. Every field is optional;
7893 an empty object means every default.
7894
7895 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
7896
7897 What happens when a thinking block in `messages` fails the conversation
7898 check: it was created in a different conversation, or the messages before
7899 it have changed since. `"error"` (the default) fails the request with a
7900 400 error. `"drop_block"` removes the failing blocks and the request
7901 proceeds; the model no longer sees the dropped reasoning.
7902
7903 - `"error"`
7904
7905 - `"drop_block"`
7906
76827907 - `display: optional "summarized" or "omitted" or "updates" or null`
76837908
76847909 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 7921
76967921 - `BetaThinkingConfigAdaptive object`
76977922
76987923 - `type: "adaptive"`
7924
7925 - `block_binding: optional BetaThinkingBlockBinding or null`
7926
7927 Controls for block binding: what happens when a thinking block this
7928 request sends back fails the conversation check. Every field is optional;
7929 an empty object means every default.
76997930
77007931 - `display: optional "summarized" or "omitted" or "updates" or null`
77017932
from line 8319
80888319
80898320 - `type: "browser_toolset_20260801"`
80908321
8091 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
8092
8093 - `"direct"`
8094
8095 - `"code_execution_20250825"`
8096
8097 - `"code_execution_20260120"`
8098
8099 - `"code_execution_20260521"`
8100
81018322 - `cache_control: optional BetaCacheControlEphemeral or null`
81028323
81038324 Create a cache control breakpoint at this content block.
from line 8944
87238944 via `configs.zoom.enabled`.
87248945
87258946 - `type: "computer_toolset_20260801"`
8726
8727 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
8728
8729 - `"direct"`
8730
8731 - `"code_execution_20250825"`
8732
8733 - `"code_execution_20260120"`
8734
8735 - `"code_execution_20260521"`
87368947
87378948 - `cache_control: optional BetaCacheControlEphemeral or null`
87388949
from line 9982
97719982
97729983 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
97739984
9774 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
9985 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
97759986
97769987 The model that will complete your prompt.
97779988
97789989 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
97799990
9991 - `"claude-fable-5-1"`
9992
9993 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
9994
9995 - `"claude-mythos-5-1"`
9996
9997 Our most capable model for cybersecurity and biology research, available through trusted access programs
9998
97809999 - `"claude-sonnet-5"`
978110000
978210001 High-performance model for coding and agents
from line 10132
991310132
991410133 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
991510134
9916 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
10135 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
991710136
991810137 The model that will complete your prompt.
991910138
992010139 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
10140
10141 - `"claude-fable-5-1"`
10142
10143 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
10144
10145 - `"claude-mythos-5-1"`
10146
10147 Our most capable model for cybersecurity and biology research, available through trusted access programs
992110148
992210149 - `"claude-sonnet-5"`
992310150
from line 11492
1126511492 from its schema.
1126611493
1126711494 - `type: "browser_toolset_20260801"`
11268
11269 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
11270
11271 - `"direct"`
11272
11273 - `"code_execution_20250825"`
11274
11275 - `"code_execution_20260120"`
11276
11277 - `"code_execution_20260521"`
1127811495
1127911496 - `cache_control: optional BetaCacheControlEphemeral or null`
1128011497
from line 13922
1370513922
1370613923 - `type: "computer_toolset_20260801"`
1370713924
13708 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
13709
13710 - `"direct"`
13711
13712 - `"code_execution_20250825"`
13713
13714 - `"code_execution_20260120"`
13715
13716 - `"code_execution_20260521"`
13717
1371813925 - `cache_control: optional BetaCacheControlEphemeral or null`
1371913926
1372013927 Create a cache control breakpoint at this content block.
from line 15427
1522015427
1522115428 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1522215429
15223 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
15430 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1522415431
1522515432 The model that will complete your prompt.
1522615433
1522715434 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
15435
15436 - `"claude-fable-5-1"`
15437
15438 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
15439
15440 - `"claude-mythos-5-1"`
15441
15442 Our most capable model for cybersecurity and biology research, available through trusted access programs
1522815443
1522915444 - `"claude-sonnet-5"`
1523015445
from line 16766
1655116766
1655216767 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1655316768
16554 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
16769 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1655516770
1655616771 The model that will complete your prompt.
1655716772
1655816773 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
16774
16775 - `"claude-fable-5-1"`
16776
16777 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
16778
16779 - `"claude-mythos-5-1"`
16780
16781 Our most capable model for cybersecurity and biology research, available through trusted access programs
1655916782
1656016783 - `"claude-sonnet-5"`
1656116784
from line 17630
1740717630
1740817631 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1740917632
17410 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
17633 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1741117634
1741217635 The model that will complete your prompt.
1741317636
1741417637 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
17638
17639 - `"claude-fable-5-1"`
17640
17641 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
17642
17643 - `"claude-mythos-5-1"`
17644
17645 Our most capable model for cybersecurity and biology research, available through trusted access programs
1741517646
1741617647 - `"claude-sonnet-5"`
1741717648
from line 17774
1754317774
1754417775 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1754517776
17546 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
17777 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1754717778
1754817779 The model that will complete your prompt.
1754917780
1755017781 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
17782
17783 - `"claude-fable-5-1"`
17784
17785 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
17786
17787 - `"claude-mythos-5-1"`
17788
17789 Our most capable model for cybersecurity and biology research, available through trusted access programs
1755117790
1755217791 - `"claude-sonnet-5"`
1755317792
from line 18035
1779618035
1779718036 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1779818037
17799 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
18038 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1780018039
1780118040 The model that will complete your prompt.
1780218041
1780318042 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1780418043
18044 - `"claude-fable-5-1"`
18045
18046 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
18047
18048 - `"claude-mythos-5-1"`
18049
18050 Our most capable model for cybersecurity and biology research, available through trusted access programs
18051
1780518052 - `"claude-sonnet-5"`
1780618053
1780718054 High-performance model for coding and agents
from line 18123
1787618123
1787718124 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1787818125
17879 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
18126 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1788018127
1788118128 The model that will complete your prompt.
1788218129
1788318130 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
18131
18132 - `"claude-fable-5-1"`
18133
18134 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
18135
18136 - `"claude-mythos-5-1"`
18137
18138 Our most capable model for cybersecurity and biology research, available through trusted access programs
1788418139
1788518140 - `"claude-sonnet-5"`
1788618141
from line 18250
1799518250
1799618251 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1799718252
17998 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
18253 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1799918254
1800018255 The model that will complete your prompt.
1800118256
1800218257 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
18258
18259 - `"claude-fable-5-1"`
18260
18261 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
18262
18263 - `"claude-mythos-5-1"`
18264
18265 Our most capable model for cybersecurity and biology research, available through trusted access programs
1800318266
1800418267 - `"claude-sonnet-5"`
1800518268
from line 18355
1809218355
1809318356 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1809418357
18095 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
18358 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1809618359
1809718360 The model that will complete your prompt.
1809818361
1809918362 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1810018363
18364 - `"claude-fable-5-1"`
18365
18366 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
18367
18368 - `"claude-mythos-5-1"`
18369
18370 Our most capable model for cybersecurity and biology research, available through trusted access programs
18371
1810118372 - `"claude-sonnet-5"`
1810218373
1810318374 High-performance model for coding and agents
from line 18503
1823218503
1823318504 - `type: "enabled"`
1823418505
18506 - `block_binding: optional BetaThinkingBlockBinding or null`
18507
18508 Controls for block binding: what happens when a thinking block this
18509 request sends back fails the conversation check. Every field is optional;
18510 an empty object means every default.
18511
18512 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
18513
18514 What happens when a thinking block in `messages` fails the conversation
18515 check: it was created in a different conversation, or the messages before
18516 it have changed since. `"error"` (the default) fails the request with a
18517 400 error. `"drop_block"` removes the failing blocks and the request
18518 proceeds; the model no longer sees the dropped reasoning.
18519
18520 - `"error"`
18521
18522 - `"drop_block"`
18523
1823518524 - `display: optional "summarized" or "omitted" or "updates" or null`
1823618525
1823718526 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 18539
1825018539
1825118540 - `type: "adaptive"`
1825218541
18542 - `block_binding: optional BetaThinkingBlockBinding or null`
18543
18544 Controls for block binding: what happens when a thinking block this
18545 request sends back fails the conversation check. Every field is optional;
18546 an empty object means every default.
18547
1825318548 - `display: optional "summarized" or "omitted" or "updates" or null`
1825418549
1825518550 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 18603
1830818603
1830918604 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1831018605
18311 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
18606 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1831218607
1831318608 The model that will complete your prompt.
1831418609
1831518610 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1831618611
18612 - `"claude-fable-5-1"`
18613
18614 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
18615
18616 - `"claude-mythos-5-1"`
18617
18618 Our most capable model for cybersecurity and biology research, available through trusted access programs
18619
1831718620 - `"claude-sonnet-5"`
1831818621
1831918622 High-performance model for coding and agents
from line 18751
1844818751
1844918752 - `type: "enabled"`
1845018753
18754 - `block_binding: optional BetaThinkingBlockBinding or null`
18755
18756 Controls for block binding: what happens when a thinking block this
18757 request sends back fails the conversation check. Every field is optional;
18758 an empty object means every default.
18759
18760 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
18761
18762 What happens when a thinking block in `messages` fails the conversation
18763 check: it was created in a different conversation, or the messages before
18764 it have changed since. `"error"` (the default) fails the request with a
18765 400 error. `"drop_block"` removes the failing blocks and the request
18766 proceeds; the model no longer sees the dropped reasoning.
18767
18768 - `"error"`
18769
18770 - `"drop_block"`
18771
1845118772 - `display: optional "summarized" or "omitted" or "updates" or null`
1845218773
1845318774 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 18786
1846518786 - `BetaThinkingConfigAdaptive object`
1846618787
1846718788 - `type: "adaptive"`
18789
18790 - `block_binding: optional BetaThinkingBlockBinding or null`
18791
18792 Controls for block binding: what happens when a thinking block this
18793 request sends back fails the conversation check. Every field is optional;
18794 an empty object means every default.
1846818795
1846918796 - `display: optional "summarized" or "omitted" or "updates" or null`
1847018797
from line 18994
1866718994
1866818995 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1866918996
18670 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
18997 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
1867118998
1867218999 The model that will complete your prompt.
1867319000
1867419001 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
19002
19003 - `"claude-fable-5-1"`
19004
19005 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
19006
19007 - `"claude-mythos-5-1"`
19008
19009 Our most capable model for cybersecurity and biology research, available through trusted access programs
1867519010
1867619011 - `"claude-sonnet-5"`
1867719012
from line 20724
2038920724
2039020725 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2039120726
20392 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
20727 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
2039320728
2039420729 The model that will complete your prompt.
2039520730
2039620731 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
20732
20733 - `"claude-fable-5-1"`
20734
20735 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
20736
20737 - `"claude-mythos-5-1"`
20738
20739 Our most capable model for cybersecurity and biology research, available through trusted access programs
2039720740
2039820741 - `"claude-sonnet-5"`
2039920742
from line 21469
2112621469
2112721470 - `"fast"`
2112821471
21472 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
21473
21474 Changes the API made to the request's input before showing it to the model:
21475 one entry per change, in request order. Today the only entry type is
21476 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
21477 block from the request's `messages` that was removed from the prompt instead
21478 of being shown to the model because it failed a binding check. More entry
21479 types may be added over time; ignore types you do not recognize.
21480
21481 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
21482 every such response from a model that supports extended thinking, as `[]`
21483 when nothing was changed; without the beta, blocks are removed all the same
21484 but nothing is reported. Removed blocks contribute nothing to
21485 `usage.input_tokens`. When streaming, the array is final in `message_start`;
21486 the final `message_delta` event carries it only when a server-side model
21487 fallback happened mid-stream, in which case it holds the serving model's
21488 entries and replaces the one in `message_start`.
21489
21490 - `path: string`
21491
21492 Where the removed block was in your request, as `messages.{i}.content.{j}`:
21493 `i` indexes the `messages` array you sent and `j` that message's `content`
21494 array — the same form error messages use.
21495
21496 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
21497
21498 Which binding check removed the block: `model_binding_mismatch` — it was
21499 created by a model whose reasoning the requested model may not read;
21500 `prefix_binding_mismatch` — the conversation before it differs from the
21501 conversation it was created in (the rest of that turn's consecutive thinking
21502 blocks are removed with it, each with this reason);
21503 `organization_binding_mismatch` — it was created under a different
21504 organization (an Anthropic organization, AWS account or Google Cloud project)
21505 and this organization is not one of its additional organizations;
21506 `end_user_binding_mismatch` — it was created for a different end user, or
21507 was removed by the consumer-organization binding. A block that would fail
21508 several checks reports one reason, in this order of precedence:
21509 `organization_binding_mismatch`, `end_user_binding_mismatch`,
21510 `model_binding_mismatch`, `prefix_binding_mismatch`.
21511
21512 - `"model_binding_mismatch"`
21513
21514 - `"prefix_binding_mismatch"`
21515
21516 - `"organization_binding_mismatch"`
21517
21518 - `"end_user_binding_mismatch"`
21519
21520 - `type: "thinking_dropped"`
21521
21522 Always `thinking_dropped` for this entry type.
21523
21524 default: thinking_dropped
21525
2112921526### Beta Message Delta Usage
2113021527
2113121528- `BetaMessageDeltaUsage object`
from line 21673
2127621673
2127721674 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2127821675
21279 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
21676 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
2128021677
2128121678 The model that will complete your prompt.
2128221679
2128321680 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
21681
21682 - `"claude-fable-5-1"`
21683
21684 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
21685
21686 - `"claude-mythos-5-1"`
21687
21688 Our most capable model for cybersecurity and biology research, available through trusted access programs
2128421689
2128521690 - `"claude-sonnet-5"`
2128621691
from line 21980
2157521980
2157621981 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2157721982
21578 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
21983 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
2157921984
2158021985 The model that will complete your prompt.
2158121986
2158221987 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
21988
21989 - `"claude-fable-5-1"`
21990
21991 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
21992
21993 - `"claude-mythos-5-1"`
21994
21995 Our most capable model for cybersecurity and biology research, available through trusted access programs
2158321996
2158421997 - `"claude-sonnet-5"`
2158521998
from line 23295
2288223295
2288323296 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2288423297
22885 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
23298 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
2288623299
2288723300 The model that will complete your prompt.
2288823301
2288923302 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2289023303
23304 - `"claude-fable-5-1"`
23305
23306 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
23307
23308 - `"claude-mythos-5-1"`
23309
23310 Our most capable model for cybersecurity and biology research, available through trusted access programs
23311
2289123312 - `"claude-sonnet-5"`
2289223313
2289323314 High-performance model for coding and agents
from line 23388
2296723388 - `"assistant"`
2296823389
2296923390 - `"system"`
23391
23392 - `clear_at: optional "next_user_message" or "never" or null`
23393
23394 How long this system message's text stays in front of the model. `"never"` (the default) renders it on every request that includes it. `"next_user_message"` renders it only for the user turn it follows: once a later `role: "user"` message exists in `messages` the message stays in the array (send it unchanged) but is no longer shown to the model. Only permitted on `role: "system"` messages.
23395
23396 - `"next_user_message"`
23397
23398 - `"never"`
23399
23400 - `output_config: optional BetaSystemMessageOutputConfig or null`
23401
23402 Per-message output configuration on a role:"system" input message.
23403
23404 Fields here apply per-turn; `format` remains top-level only. An
23405 empty `{}` is accepted on a message that carries content; a message
23406 with neither content nor output_config fields is rejected.
23407
23408 - `effort: optional "low" or "medium" or "high" or 2 more or null`
23409
23410 All possible effort levels.
23411
23412 - `"low"`
23413
23414 - `"medium"`
23415
23416 - `"high"`
23417
23418 - `"xhigh"`
23419
23420 - `"max"`
2297023421
2297123422### Beta Message Tokens Count
2297223423
from line 24770
2431924770
2432024771 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2432124772
24322 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
24773 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
2432324774
2432424775 The model that will complete your prompt.
2432524776
2432624777 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
24778
24779 - `"claude-fable-5-1"`
24780
24781 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
24782
24783 - `"claude-mythos-5-1"`
24784
24785 Our most capable model for cybersecurity and biology research, available through trusted access programs
2432724786
2432824787 - `"claude-sonnet-5"`
2432924788
from line 25263
2480425263
2480525264 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2480625265
24807 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
25266 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
2480825267
2480925268 The model that will complete your prompt.
2481025269
2481125270 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
25271
25272 - `"claude-fable-5-1"`
25273
25274 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
25275
25276 - `"claude-mythos-5-1"`
25277
25278 Our most capable model for cybersecurity and biology research, available through trusted access programs
2481225279
2481325280 - `"claude-sonnet-5"`
2481425281
from line 25523
2505625523 The number of web search tool requests.
2505725524
2505825525 default: 0, minimum: 0
25526
25527 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
25528
25529 Changes the API made to the request's input before showing it to the model:
25530 one entry per change, in request order. Today the only entry type is
25531 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
25532 block from the request's `messages` that was removed from the prompt instead
25533 of being shown to the model because it failed a binding check. More entry
25534 types may be added over time; ignore types you do not recognize.
25535
25536 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
25537 every such response from a model that supports extended thinking, as `[]`
25538 when nothing was changed; without the beta, blocks are removed all the same
25539 but nothing is reported. Removed blocks contribute nothing to
25540 `usage.input_tokens`. When streaming, the array is final in `message_start`;
25541 the final `message_delta` event carries it only when a server-side model
25542 fallback happened mid-stream, in which case it holds the serving model's
25543 entries and replaces the one in `message_start`.
25544
25545 - `path: string`
25546
25547 Where the removed block was in your request, as `messages.{i}.content.{j}`:
25548 `i` indexes the `messages` array you sent and `j` that message's `content`
25549 array — the same form error messages use.
25550
25551 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
25552
25553 Which binding check removed the block: `model_binding_mismatch` — it was
25554 created by a model whose reasoning the requested model may not read;
25555 `prefix_binding_mismatch` — the conversation before it differs from the
25556 conversation it was created in (the rest of that turn's consecutive thinking
25557 blocks are removed with it, each with this reason);
25558 `organization_binding_mismatch` — it was created under a different
25559 organization (an Anthropic organization, AWS account or Google Cloud project)
25560 and this organization is not one of its additional organizations;
25561 `end_user_binding_mismatch` — it was created for a different end user, or
25562 was removed by the consumer-organization binding. A block that would fail
25563 several checks reports one reason, in this order of precedence:
25564 `organization_binding_mismatch`, `end_user_binding_mismatch`,
25565 `model_binding_mismatch`, `prefix_binding_mismatch`.
25566
25567 - `"model_binding_mismatch"`
25568
25569 - `"prefix_binding_mismatch"`
25570
25571 - `"organization_binding_mismatch"`
25572
25573 - `"end_user_binding_mismatch"`
25574
25575 - `type: "thinking_dropped"`
25576
25577 Always `thinking_dropped` for this entry type.
25578
25579 default: thinking_dropped
2505925580
2506025581### Beta Raw Message Start Event
2506125582
from line 26505
2598426505
2598526506 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2598626507
25987 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
26508 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
2598826509
2598926510 The model that will complete your prompt.
2599026511
2599126512 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
26513
26514 - `"claude-fable-5-1"`
26515
26516 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
26517
26518 - `"claude-mythos-5-1"`
26519
26520 Our most capable model for cybersecurity and biology research, available through trusted access programs
2599226521
2599326522 - `"claude-sonnet-5"`
2599426523
from line 27250
2672127250
2672227251 - `"fast"`
2672327252
27253 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
27254
27255 Changes the API made to the request's input before showing it to the model:
27256 one entry per change, in request order. Today the only entry type is
27257 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
27258 block from the request's `messages` that was removed from the prompt instead
27259 of being shown to the model because it failed a binding check. More entry
27260 types may be added over time; ignore types you do not recognize.
27261
27262 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
27263 every such response from a model that supports extended thinking, as `[]`
27264 when nothing was changed; without the beta, blocks are removed all the same
27265 but nothing is reported. Removed blocks contribute nothing to
27266 `usage.input_tokens`. When streaming, the array is final in `message_start`;
27267 the final `message_delta` event carries it only when a server-side model
27268 fallback happened mid-stream, in which case it holds the serving model's
27269 entries and replaces the one in `message_start`.
27270
27271 - `path: string`
27272
27273 Where the removed block was in your request, as `messages.{i}.content.{j}`:
27274 `i` indexes the `messages` array you sent and `j` that message's `content`
27275 array — the same form error messages use.
27276
27277 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
27278
27279 Which binding check removed the block: `model_binding_mismatch` — it was
27280 created by a model whose reasoning the requested model may not read;
27281 `prefix_binding_mismatch` — the conversation before it differs from the
27282 conversation it was created in (the rest of that turn's consecutive thinking
27283 blocks are removed with it, each with this reason);
27284 `organization_binding_mismatch` — it was created under a different
27285 organization (an Anthropic organization, AWS account or Google Cloud project)
27286 and this organization is not one of its additional organizations;
27287 `end_user_binding_mismatch` — it was created for a different end user, or
27288 was removed by the consumer-organization binding. A block that would fail
27289 several checks reports one reason, in this order of precedence:
27290 `organization_binding_mismatch`, `end_user_binding_mismatch`,
27291 `model_binding_mismatch`, `prefix_binding_mismatch`.
27292
27293 - `"model_binding_mismatch"`
27294
27295 - `"prefix_binding_mismatch"`
27296
27297 - `"organization_binding_mismatch"`
27298
27299 - `"end_user_binding_mismatch"`
27300
27301 - `type: "thinking_dropped"`
27302
27303 Always `thinking_dropped` for this entry type.
27304
27305 default: thinking_dropped
27306
2672427307 - `type: "message_start"`
2672527308
2672627309 default: message_start
from line 28245
2766228245
2766328246 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
2766428247
27665 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
28248 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
2766628249
2766728250 The model that will complete your prompt.
2766828251
2766928252 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
28253
28254 - `"claude-fable-5-1"`
28255
28256 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
28257
28258 - `"claude-mythos-5-1"`
28259
28260 Our most capable model for cybersecurity and biology research, available through trusted access programs
2767028261
2767128262 - `"claude-sonnet-5"`
2767228263
from line 28990
2839928990
2840028991 - `"fast"`
2840128992
28993 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
28994
28995 Changes the API made to the request's input before showing it to the model:
28996 one entry per change, in request order. Today the only entry type is
28997 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
28998 block from the request's `messages` that was removed from the prompt instead
28999 of being shown to the model because it failed a binding check. More entry
29000 types may be added over time; ignore types you do not recognize.
29001
29002 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
29003 every such response from a model that supports extended thinking, as `[]`
29004 when nothing was changed; without the beta, blocks are removed all the same
29005 but nothing is reported. Removed blocks contribute nothing to
29006 `usage.input_tokens`. When streaming, the array is final in `message_start`;
29007 the final `message_delta` event carries it only when a server-side model
29008 fallback happened mid-stream, in which case it holds the serving model's
29009 entries and replaces the one in `message_start`.
29010
29011 - `path: string`
29012
29013 Where the removed block was in your request, as `messages.{i}.content.{j}`:
29014 `i` indexes the `messages` array you sent and `j` that message's `content`
29015 array — the same form error messages use.
29016
29017 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
29018
29019 Which binding check removed the block: `model_binding_mismatch` — it was
29020 created by a model whose reasoning the requested model may not read;
29021 `prefix_binding_mismatch` — the conversation before it differs from the
29022 conversation it was created in (the rest of that turn's consecutive thinking
29023 blocks are removed with it, each with this reason);
29024 `organization_binding_mismatch` — it was created under a different
29025 organization (an Anthropic organization, AWS account or Google Cloud project)
29026 and this organization is not one of its additional organizations;
29027 `end_user_binding_mismatch` — it was created for a different end user, or
29028 was removed by the consumer-organization binding. A block that would fail
29029 several checks reports one reason, in this order of precedence:
29030 `organization_binding_mismatch`, `end_user_binding_mismatch`,
29031 `model_binding_mismatch`, `prefix_binding_mismatch`.
29032
29033 - `"model_binding_mismatch"`
29034
29035 - `"prefix_binding_mismatch"`
29036
29037 - `"organization_binding_mismatch"`
29038
29039 - `"end_user_binding_mismatch"`
29040
29041 - `type: "thinking_dropped"`
29042
29043 Always `thinking_dropped` for this entry type.
29044
29045 default: thinking_dropped
29046
2840229047 - `type: "message_start"`
2840329048
2840429049 default: message_start
from line 29134
2848929134 - `server_tool_use: BetaServerToolUsage or null`
2849029135
2849129136 The number of server tool requests.
29137
29138 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
29139
29140 Changes the API made to the request's input before showing it to the model:
29141 one entry per change, in request order. Today the only entry type is
29142 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
29143 block from the request's `messages` that was removed from the prompt instead
29144 of being shown to the model because it failed a binding check. More entry
29145 types may be added over time; ignore types you do not recognize.
29146
29147 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
29148 every such response from a model that supports extended thinking, as `[]`
29149 when nothing was changed; without the beta, blocks are removed all the same
29150 but nothing is reported. Removed blocks contribute nothing to
29151 `usage.input_tokens`. When streaming, the array is final in `message_start`;
29152 the final `message_delta` event carries it only when a server-side model
29153 fallback happened mid-stream, in which case it holds the serving model's
29154 entries and replaces the one in `message_start`.
29155
29156 - `path: string`
29157
29158 Where the removed block was in your request, as `messages.{i}.content.{j}`:
29159 `i` indexes the `messages` array you sent and `j` that message's `content`
29160 array — the same form error messages use.
29161
29162 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
29163
29164 Which binding check removed the block: `model_binding_mismatch` — it was
29165 created by a model whose reasoning the requested model may not read;
29166 `prefix_binding_mismatch` — the conversation before it differs from the
29167 conversation it was created in (the rest of that turn's consecutive thinking
29168 blocks are removed with it, each with this reason);
29169 `organization_binding_mismatch` — it was created under a different
29170 organization (an Anthropic organization, AWS account or Google Cloud project)
29171 and this organization is not one of its additional organizations;
29172 `end_user_binding_mismatch` — it was created for a different end user, or
29173 was removed by the consumer-organization binding. A block that would fail
29174 several checks reports one reason, in this order of precedence:
29175 `organization_binding_mismatch`, `end_user_binding_mismatch`,
29176 `model_binding_mismatch`, `prefix_binding_mismatch`.
29177
29178 - `type: "thinking_dropped"`
29179
29180 Always `thinking_dropped` for this entry type.
29181
29182 default: thinking_dropped
2849229183
2849329184 - `BetaRawMessageStopEvent object`
2849429185
from line 30468
2977730468
2977830469 - `"model_context_window_exceeded"`
2977930470
30471### Beta System Message Output Config
30472
30473- `BetaSystemMessageOutputConfig object`
30474
30475 Per-message output configuration on a role:"system" input message.
30476
30477 Fields here apply per-turn; `format` remains top-level only. An
30478 empty `{}` is accepted on a message that carries content; a message
30479 with neither content nor output_config fields is rejected.
30480
30481 - `effort: optional "low" or "medium" or "high" or 2 more or null`
30482
30483 All possible effort levels.
30484
30485 - `"low"`
30486
30487 - `"medium"`
30488
30489 - `"high"`
30490
30491 - `"xhigh"`
30492
30493 - `"max"`
30494
2978030495### Beta Text Block
2978130496
2978230497- `BetaTextBlock object`
from line 31388
3067331388
3067431389 default: thinking
3067531390
31391### Beta Thinking Block Binding
31392
31393- `BetaThinkingBlockBinding object`
31394
31395 Controls for block binding: what happens when a thinking block this
31396 request sends back fails the conversation check. Every field is optional;
31397 an empty object means every default.
31398
31399 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
31400
31401 What happens when a thinking block in `messages` fails the conversation
31402 check: it was created in a different conversation, or the messages before
31403 it have changed since. `"error"` (the default) fails the request with a
31404 400 error. `"drop_block"` removes the failing blocks and the request
31405 proceeds; the model no longer sees the dropped reasoning.
31406
31407 - `"error"`
31408
31409 - `"drop_block"`
31410
3067631411### Beta Thinking Block Param
3067731412
3067831413- `BetaThinkingBlockParam object`
from line 31430
3069531430
3069631431 - `type: "adaptive"`
3069731432
31433 - `block_binding: optional BetaThinkingBlockBinding or null`
31434
31435 Controls for block binding: what happens when a thinking block this
31436 request sends back fails the conversation check. Every field is optional;
31437 an empty object means every default.
31438
31439 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
31440
31441 What happens when a thinking block in `messages` fails the conversation
31442 check: it was created in a different conversation, or the messages before
31443 it have changed since. `"error"` (the default) fails the request with a
31444 400 error. `"drop_block"` removes the failing blocks and the request
31445 proceeds; the model no longer sees the dropped reasoning.
31446
31447 - `"error"`
31448
31449 - `"drop_block"`
31450
3069831451 - `display: optional "summarized" or "omitted" or "updates" or null`
3069931452
3070031453 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 31480
3072731480
3072831481 - `type: "enabled"`
3072931482
31483 - `block_binding: optional BetaThinkingBlockBinding or null`
31484
31485 Controls for block binding: what happens when a thinking block this
31486 request sends back fails the conversation check. Every field is optional;
31487 an empty object means every default.
31488
31489 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
31490
31491 What happens when a thinking block in `messages` fails the conversation
31492 check: it was created in a different conversation, or the messages before
31493 it have changed since. `"error"` (the default) fails the request with a
31494 400 error. `"drop_block"` removes the failing blocks and the request
31495 proceeds; the model no longer sees the dropped reasoning.
31496
31497 - `"error"`
31498
31499 - `"drop_block"`
31500
3073031501 - `display: optional "summarized" or "omitted" or "updates" or null`
3073131502
3073231503 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 31532
3076131532
3076231533 - `type: "enabled"`
3076331534
31535 - `block_binding: optional BetaThinkingBlockBinding or null`
31536
31537 Controls for block binding: what happens when a thinking block this
31538 request sends back fails the conversation check. Every field is optional;
31539 an empty object means every default.
31540
31541 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
31542
31543 What happens when a thinking block in `messages` fails the conversation
31544 check: it was created in a different conversation, or the messages before
31545 it have changed since. `"error"` (the default) fails the request with a
31546 400 error. `"drop_block"` removes the failing blocks and the request
31547 proceeds; the model no longer sees the dropped reasoning.
31548
31549 - `"error"`
31550
31551 - `"drop_block"`
31552
3076431553 - `display: optional "summarized" or "omitted" or "updates" or null`
3076531554
3076631555 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 31568
3077931568
3078031569 - `type: "adaptive"`
3078131570
31571 - `block_binding: optional BetaThinkingBlockBinding or null`
31572
31573 Controls for block binding: what happens when a thinking block this
31574 request sends back fails the conversation check. Every field is optional;
31575 an empty object means every default.
31576
3078231577 - `display: optional "summarized" or "omitted" or "updates" or null`
3078331578
3078431579 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 31599
3080431599 - `type: "thinking_delta"`
3080531600
3080631601 default: thinking_delta
31602
31603### Beta Thinking Dropped Input Transformation
31604
31605- `BetaThinkingDroppedInputTransformation object`
31606
31607 - `path: string`
31608
31609 Where the removed block was in your request, as `messages.{i}.content.{j}`:
31610 `i` indexes the `messages` array you sent and `j` that message's `content`
31611 array — the same form error messages use.
31612
31613 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
31614
31615 Which binding check removed the block: `model_binding_mismatch` — it was
31616 created by a model whose reasoning the requested model may not read;
31617 `prefix_binding_mismatch` — the conversation before it differs from the
31618 conversation it was created in (the rest of that turn's consecutive thinking
31619 blocks are removed with it, each with this reason);
31620 `organization_binding_mismatch` — it was created under a different
31621 organization (an Anthropic organization, AWS account or Google Cloud project)
31622 and this organization is not one of its additional organizations;
31623 `end_user_binding_mismatch` — it was created for a different end user, or
31624 was removed by the consumer-organization binding. A block that would fail
31625 several checks reports one reason, in this order of precedence:
31626 `organization_binding_mismatch`, `end_user_binding_mismatch`,
31627 `model_binding_mismatch`, `prefix_binding_mismatch`.
31628
31629 - `"model_binding_mismatch"`
31630
31631 - `"prefix_binding_mismatch"`
31632
31633 - `"organization_binding_mismatch"`
31634
31635 - `"end_user_binding_mismatch"`
31636
31637 - `type: "thinking_dropped"`
31638
31639 Always `thinking_dropped` for this entry type.
31640
31641 default: thinking_dropped
31642
31643### Beta Thinking Prefix Mismatch Behavior
31644
31645- `BetaThinkingPrefixMismatchBehavior = "error" or "drop_block"`
31646
31647 What happens when a thinking block in `messages` fails the conversation
31648 check: it was created in a different conversation, or the messages before
31649 it have changed since. `"error"` (the default) fails the request with a
31650 400 error. `"drop_block"` removes the failing blocks and the request
31651 proceeds; the model no longer sees the dropped reasoning.
31652
31653 - `"error"`
31654
31655 - `"drop_block"`
3080731656
3080831657### Beta Thinking Turns
3080931658
from line 33578
3272933578 from its schema.
3273033579
3273133580 - `type: "browser_toolset_20260801"`
32732
32733 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
32734
32735 - `"direct"`
32736
32737 - `"code_execution_20250825"`
32738
32739 - `"code_execution_20260120"`
32740
32741 - `"code_execution_20260521"`
3274233581
3274333582 - `cache_control: optional BetaCacheControlEphemeral or null`
3274433583
from line 34205
3336634205
3336734206 - `type: "computer_toolset_20260801"`
3336834207
33369 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
33370
33371 - `"direct"`
33372
33373 - `"code_execution_20250825"`
33374
33375 - `"code_execution_20260120"`
33376
33377 - `"code_execution_20260521"`
33378
3337934208 - `cache_control: optional BetaCacheControlEphemeral or null`
3338034209
3338134210 Create a cache control breakpoint at this content block.
from line 34966
3413734966
3413834967 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
3413934968
34140 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
34969 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
3414134970
3414234971 The model that will complete your prompt.
3414334972
3414434973 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
34974
34975 - `"claude-fable-5-1"`
34976
34977 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
34978
34979 - `"claude-mythos-5-1"`
34980
34981 Our most capable model for cybersecurity and biology research, available through trusted access programs
3414534982
3414634983 - `"claude-sonnet-5"`
3414734984
from line 35512
3467535512
3467635513 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
3467735514
34678 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
35515 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
3467935516
3468035517 The model that will complete your prompt.
3468135518
3468235519 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
35520
35521 - `"claude-fable-5-1"`
35522
35523 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
35524
35525 - `"claude-mythos-5-1"`
35526
35527 Our most capable model for cybersecurity and biology research, available through trusted access programs
3468335528
3468435529 - `"claude-sonnet-5"`
3468535530
from line 37663
3681837663
3681937664 - `string`
3682037665
36821 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
37666 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
3682237667
3682337668 - `"message-batches-2024-09-24"`
3682437669
from line 37746
3690137746 - `"thinking-display-updates-2026-08-18"`
3690237747
3690337748 - `"ce-user-management-2026-07-13"`
37749
37750 - `"mid-conversation-output-config-2026-07-01"`
37751
37752 - `"thinking-binding-controls-2026-08-01"`
37753
37754 - `"mid-conversation-system-clear-at-2026-08-21"`
3690437755
3690537756- `"anthropic-user-profile-id": optional string`
3690637757
from line 39065
3821439065
3821539066 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
3821639067
38217 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
39068 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
3821839069
3821939070 The model that will complete your prompt.
3822039071
3822139072 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
3822239073
39074 - `"claude-fable-5-1"`
39075
39076 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
39077
39078 - `"claude-mythos-5-1"`
39079
39080 Our most capable model for cybersecurity and biology research, available through trusted access programs
39081
3822339082 - `"claude-sonnet-5"`
3822439083
3822539084 High-performance model for coding and agents
from line 39158
3829939158 - `"assistant"`
3830039159
3830139160 - `"system"`
39161
39162 - `clear_at: optional "next_user_message" or "never" or null`
39163
39164 How long this system message's text stays in front of the model. `"never"` (the default) renders it on every request that includes it. `"next_user_message"` renders it only for the user turn it follows: once a later `role: "user"` message exists in `messages` the message stays in the array (send it unchanged) but is no longer shown to the model. Only permitted on `role: "system"` messages.
39165
39166 - `"next_user_message"`
39167
39168 - `"never"`
39169
39170 - `output_config: optional BetaSystemMessageOutputConfig or null`
39171
39172 Per-message output configuration on a role:"system" input message.
39173
39174 Fields here apply per-turn; `format` remains top-level only. An
39175 empty `{}` is accepted on a message that carries content; a message
39176 with neither content nor output_config fields is rejected.
39177
39178 - `effort: optional "low" or "medium" or "high" or 2 more or null`
39179
39180 All possible effort levels.
39181
39182 - `"low"`
39183
39184 - `"medium"`
39185
39186 - `"high"`
39187
39188 - `"xhigh"`
39189
39190 - `"max"`
3830239191
3830339192 - `model: Model`
3830439193
from line 39491
3860239491
3860339492 - `type: "enabled"`
3860439493
39494 - `block_binding: optional BetaThinkingBlockBinding or null`
39495
39496 Controls for block binding: what happens when a thinking block this
39497 request sends back fails the conversation check. Every field is optional;
39498 an empty object means every default.
39499
39500 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
39501
39502 What happens when a thinking block in `messages` fails the conversation
39503 check: it was created in a different conversation, or the messages before
39504 it have changed since. `"error"` (the default) fails the request with a
39505 400 error. `"drop_block"` removes the failing blocks and the request
39506 proceeds; the model no longer sees the dropped reasoning.
39507
39508 - `"error"`
39509
39510 - `"drop_block"`
39511
3860539512 - `display: optional "summarized" or "omitted" or "updates" or null`
3860639513
3860739514 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 39526
3861939526 - `BetaThinkingConfigAdaptive object`
3862039527
3862139528 - `type: "adaptive"`
39529
39530 - `block_binding: optional BetaThinkingBlockBinding or null`
39531
39532 Controls for block binding: what happens when a thinking block this
39533 request sends back fails the conversation check. Every field is optional;
39534 an empty object means every default.
3862239535
3862339536 - `display: optional "summarized" or "omitted" or "updates" or null`
3862439537
from line 40034
3912140034
3912240035 - `type: "browser_toolset_20260801"`
3912340036
39124 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
39125
39126 - `"direct"`
39127
39128 - `"code_execution_20250825"`
39129
39130 - `"code_execution_20260120"`
39131
39132 - `"code_execution_20260521"`
39133
3913440037 - `cache_control: optional BetaCacheControlEphemeral or null`
3913540038
3913640039 Create a cache control breakpoint at this content block.
from line 40659
3975640659 via `configs.zoom.enabled`.
3975740660
3975840661 - `type: "computer_toolset_20260801"`
39759
39760 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
39761
39762 - `"direct"`
39763
39764 - `"code_execution_20250825"`
39765
39766 - `"code_execution_20260120"`
39767
39768 - `"code_execution_20260521"`
3976940662
3977040663 - `cache_control: optional BetaCacheControlEphemeral or null`
3977140664
from line 41798
4090541798
4090641799 - `string`
4090741800
40908 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
41801 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
4090941802
4091041803 - `"message-batches-2024-09-24"`
4091141804
from line 41881
4098841881 - `"thinking-display-updates-2026-08-18"`
4098941882
4099041883 - `"ce-user-management-2026-07-13"`
41884
41885 - `"mid-conversation-output-config-2026-07-01"`
41886
41887 - `"thinking-binding-controls-2026-08-01"`
41888
41889 - `"mid-conversation-system-clear-at-2026-08-21"`
4099141890
4099241891#### Returns
4099341892
from line 42064
4116542064
4116642065 - `string`
4116742066
41168 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
42067 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
4116942068
4117042069 - `"message-batches-2024-09-24"`
4117142070
from line 42147
4124842147 - `"thinking-display-updates-2026-08-18"`
4124942148
4125042149 - `"ce-user-management-2026-07-13"`
42150
42151 - `"mid-conversation-output-config-2026-07-01"`
42152
42153 - `"thinking-binding-controls-2026-08-01"`
42154
42155 - `"mid-conversation-system-clear-at-2026-08-21"`
4125142156
4125242157#### Returns
4125342158
from line 42339
4143442339
4143542340 - `string`
4143642341
41437 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
42342 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
4143842343
4143942344 - `"message-batches-2024-09-24"`
4144042345
from line 42422
4151742422 - `"thinking-display-updates-2026-08-18"`
4151842423
4151942424 - `"ce-user-management-2026-07-13"`
42425
42426 - `"mid-conversation-output-config-2026-07-01"`
42427
42428 - `"thinking-binding-controls-2026-08-01"`
42429
42430 - `"mid-conversation-system-clear-at-2026-08-21"`
4152042431
4152142432#### Returns
4152242433
from line 42596
4168542596
4168642597 - `string`
4168742598
41688 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
42599 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
4168942600
4169042601 - `"message-batches-2024-09-24"`
4169142602
from line 42679
4176842679 - `"thinking-display-updates-2026-08-18"`
4176942680
4177042681 - `"ce-user-management-2026-07-13"`
42682
42683 - `"mid-conversation-output-config-2026-07-01"`
42684
42685 - `"thinking-binding-controls-2026-08-01"`
42686
42687 - `"mid-conversation-system-clear-at-2026-08-21"`
4177142688
4177242689#### Returns
4177342690
from line 42745
4182842745
4182942746 - `string`
4183042747
41831 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
42748 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
4183242749
4183342750 - `"message-batches-2024-09-24"`
4183442751
from line 42828
4191142828 - `"thinking-display-updates-2026-08-18"`
4191242829
4191342830 - `"ce-user-management-2026-07-13"`
42831
42832 - `"mid-conversation-output-config-2026-07-01"`
42833
42834 - `"thinking-binding-controls-2026-08-01"`
42835
42836 - `"mid-conversation-system-clear-at-2026-08-21"`
4191442837
4191542838#### Returns
4191642839
from line 43778
4285543778
4285643779 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
4285743780
42858 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
43781 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
4285943782
4286043783 The model that will complete your prompt.
4286143784
4286243785 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
43786
43787 - `"claude-fable-5-1"`
43788
43789 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
43790
43791 - `"claude-mythos-5-1"`
43792
43793 Our most capable model for cybersecurity and biology research, available through trusted access programs
4286343794
4286443795 - `"claude-sonnet-5"`
4286543796
from line 44523
4359244523
4359344524 - `"fast"`
4359444525
44526 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
44527
44528 Changes the API made to the request's input before showing it to the model:
44529 one entry per change, in request order. Today the only entry type is
44530 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
44531 block from the request's `messages` that was removed from the prompt instead
44532 of being shown to the model because it failed a binding check. More entry
44533 types may be added over time; ignore types you do not recognize.
44534
44535 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
44536 every such response from a model that supports extended thinking, as `[]`
44537 when nothing was changed; without the beta, blocks are removed all the same
44538 but nothing is reported. Removed blocks contribute nothing to
44539 `usage.input_tokens`. When streaming, the array is final in `message_start`;
44540 the final `message_delta` event carries it only when a server-side model
44541 fallback happened mid-stream, in which case it holds the serving model's
44542 entries and replaces the one in `message_start`.
44543
44544 - `path: string`
44545
44546 Where the removed block was in your request, as `messages.{i}.content.{j}`:
44547 `i` indexes the `messages` array you sent and `j` that message's `content`
44548 array — the same form error messages use.
44549
44550 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
44551
44552 Which binding check removed the block: `model_binding_mismatch` — it was
44553 created by a model whose reasoning the requested model may not read;
44554 `prefix_binding_mismatch` — the conversation before it differs from the
44555 conversation it was created in (the rest of that turn's consecutive thinking
44556 blocks are removed with it, each with this reason);
44557 `organization_binding_mismatch` — it was created under a different
44558 organization (an Anthropic organization, AWS account or Google Cloud project)
44559 and this organization is not one of its additional organizations;
44560 `end_user_binding_mismatch` — it was created for a different end user, or
44561 was removed by the consumer-organization binding. A block that would fail
44562 several checks reports one reason, in this order of precedence:
44563 `organization_binding_mismatch`, `end_user_binding_mismatch`,
44564 `model_binding_mismatch`, `prefix_binding_mismatch`.
44565
44566 - `"model_binding_mismatch"`
44567
44568 - `"prefix_binding_mismatch"`
44569
44570 - `"organization_binding_mismatch"`
44571
44572 - `"end_user_binding_mismatch"`
44573
44574 - `type: "thinking_dropped"`
44575
44576 Always `thinking_dropped` for this entry type.
44577
44578 default: thinking_dropped
44579
4359544580 - `type: "succeeded"`
4359644581
4359744582 default: succeeded
4359844583
api/beta/messages/batches Changed · +357 / -31 lines
This page is larger than the 256 KiB this site keeps, so one side of the diff below stops where the stored text does.
from line 18
1818
1919 - `string`
2020
21 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
21 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2222
2323 - `"message-batches-2024-09-24"`
2424
from line 102
102102
103103 - `"ce-user-management-2026-07-13"`
104104
105 - `"mid-conversation-output-config-2026-07-01"`
106
107 - `"thinking-binding-controls-2026-08-01"`
108
109 - `"mid-conversation-system-clear-at-2026-08-21"`
110
105111- `"anthropic-user-profile-id": optional string`
106112
107113 The user profile ID to attribute the requests in this batch to. Use when acting on behalf of a party other than your organization. Requires the `user-profiles` beta header. Applies to every request in the batch; an individual request whose `user_profile_id` body field conflicts with this header is errored.
from line 1420
14141420
14151421 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
14161422
1417 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
1423 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
14181424
14191425 The model that will complete your prompt.
14201426
14211427 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
14221428
1429 - `"claude-fable-5-1"`
1430
1431 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
1432
1433 - `"claude-mythos-5-1"`
1434
1435 Our most capable model for cybersecurity and biology research, available through trusted access programs
1436
14231437 - `"claude-sonnet-5"`
14241438
14251439 High-performance model for coding and agents
from line 1514
15001514
15011515 - `"system"`
15021516
1517 - `clear_at: optional "next_user_message" or "never" or null`
1518
1519 How long this system message's text stays in front of the model. `"never"` (the default) renders it on every request that includes it. `"next_user_message"` renders it only for the user turn it follows: once a later `role: "user"` message exists in `messages` the message stays in the array (send it unchanged) but is no longer shown to the model. Only permitted on `role: "system"` messages.
1520
1521 - `"next_user_message"`
1522
1523 - `"never"`
1524
1525 - `output_config: optional BetaSystemMessageOutputConfig or null`
1526
1527 Per-message output configuration on a role:"system" input message.
1528
1529 Fields here apply per-turn; `format` remains top-level only. An
1530 empty `{}` is accepted on a message that carries content; a message
1531 with neither content nor output_config fields is rejected.
1532
1533 - `effort: optional "low" or "medium" or "high" or 2 more or null`
1534
1535 All possible effort levels.
1536
1537 - `"low"`
1538
1539 - `"medium"`
1540
1541 - `"high"`
1542
1543 - `"xhigh"`
1544
1545 - `"max"`
1546
15031547 - `model: Model`
15041548
15051549 The model that will complete your prompt.
from line 1846
18021846
18031847 - `type: "enabled"`
18041848
1849 - `block_binding: optional BetaThinkingBlockBinding or null`
1850
1851 Controls for block binding: what happens when a thinking block this
1852 request sends back fails the conversation check. Every field is optional;
1853 an empty object means every default.
1854
1855 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
1856
1857 What happens when a thinking block in `messages` fails the conversation
1858 check: it was created in a different conversation, or the messages before
1859 it have changed since. `"error"` (the default) fails the request with a
1860 400 error. `"drop_block"` removes the failing blocks and the request
1861 proceeds; the model no longer sees the dropped reasoning.
1862
1863 - `"error"`
1864
1865 - `"drop_block"`
1866
18051867 - `display: optional "summarized" or "omitted" or "updates" or null`
18061868
18071869 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 1882
18201882
18211883 - `type: "adaptive"`
18221884
1885 - `block_binding: optional BetaThinkingBlockBinding or null`
1886
1887 Controls for block binding: what happens when a thinking block this
1888 request sends back fails the conversation check. Every field is optional;
1889 an empty object means every default.
1890
18231891 - `display: optional "summarized" or "omitted" or "updates" or null`
18241892
18251893 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 2389
23212389
23222390 - `type: "browser_toolset_20260801"`
23232391
2324 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2325
2326 - `"direct"`
2327
2328 - `"code_execution_20250825"`
2329
2330 - `"code_execution_20260120"`
2331
2332 - `"code_execution_20260521"`
2333
23342392 - `cache_control: optional BetaCacheControlEphemeral or null`
23352393
23362394 Create a cache control breakpoint at this content block.
from line 3015
29573015
29583016 - `type: "computer_toolset_20260801"`
29593017
2960 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2961
2962 - `"direct"`
2963
2964 - `"code_execution_20250825"`
2965
2966 - `"code_execution_20260120"`
2967
2968 - `"code_execution_20260521"`
2969
29703018 - `cache_control: optional BetaCacheControlEphemeral or null`
29713019
29723020 Create a cache control breakpoint at this content block.
from line 4153
41054153
41064154 - `string`
41074155
4108 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
4156 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
41094157
41104158 - `"message-batches-2024-09-24"`
41114159
from line 4237
41894237
41904238 - `"ce-user-management-2026-07-13"`
41914239
4240 - `"mid-conversation-output-config-2026-07-01"`
4241
4242 - `"thinking-binding-controls-2026-08-01"`
4243
4244 - `"mid-conversation-system-clear-at-2026-08-21"`
4245
41924246### Returns
41934247
41944248- `BetaMessageBatch object`
from line 4419
43654419
43664420 - `string`
43674421
4368 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
4422 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
43694423
43704424 - `"message-batches-2024-09-24"`
43714425
from line 4503
44494503
44504504 - `"ce-user-management-2026-07-13"`
44514505
4506 - `"mid-conversation-output-config-2026-07-01"`
4507
4508 - `"thinking-binding-controls-2026-08-01"`
4509
4510 - `"mid-conversation-system-clear-at-2026-08-21"`
4511
44524512### Returns
44534513
44544514- `data: array of BetaMessageBatch`
from line 4694
46344694
46354695 - `string`
46364696
4637 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
4697 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
46384698
46394699 - `"message-batches-2024-09-24"`
46404700
from line 4778
47184778
47194779 - `"ce-user-management-2026-07-13"`
47204780
4781 - `"mid-conversation-output-config-2026-07-01"`
4782
4783 - `"thinking-binding-controls-2026-08-01"`
4784
4785 - `"mid-conversation-system-clear-at-2026-08-21"`
4786
47214787### Returns
47224788
47234789- `BetaMessageBatch object`
from line 4951
48854951
48864952 - `string`
48874953
4888 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
4954 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
48894955
48904956 - `"message-batches-2024-09-24"`
48914957
from line 5035
49695035
49705036 - `"ce-user-management-2026-07-13"`
49715037
5038 - `"mid-conversation-output-config-2026-07-01"`
5039
5040 - `"thinking-binding-controls-2026-08-01"`
5041
5042 - `"mid-conversation-system-clear-at-2026-08-21"`
5043
49725044### Returns
49735045
49745046- `BetaDeletedMessageBatch object`
from line 5100
50285100
50295101 - `string`
50305102
5031 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
5103 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
50325104
50335105 - `"message-batches-2024-09-24"`
50345106
from line 5184
51125184
51135185 - `"ce-user-management-2026-07-13"`
51145186
5187 - `"mid-conversation-output-config-2026-07-01"`
5188
5189 - `"thinking-binding-controls-2026-08-01"`
5190
5191 - `"mid-conversation-system-clear-at-2026-08-21"`
5192
51155193### Returns
51165194
51175195- `BetaMessageBatchIndividualResponse object`
from line 6133
60556133
60566134 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
60576135
6058 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
6136 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
60596137
60606138 The model that will complete your prompt.
60616139
60626140 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
60636141
6142 - `"claude-fable-5-1"`
6143
6144 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
6145
6146 - `"claude-mythos-5-1"`
6147
6148 Our most capable model for cybersecurity and biology research, available through trusted access programs
6149
60646150 - `"claude-sonnet-5"`
60656151
60666152 High-performance model for coding and agents
from line 6878
67926878
67936879 - `"fast"`
67946880
6881 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
6882
6883 Changes the API made to the request's input before showing it to the model:
6884 one entry per change, in request order. Today the only entry type is
6885 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
6886 block from the request's `messages` that was removed from the prompt instead
6887 of being shown to the model because it failed a binding check. More entry
6888 types may be added over time; ignore types you do not recognize.
6889
6890 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
6891 every such response from a model that supports extended thinking, as `[]`
6892 when nothing was changed; without the beta, blocks are removed all the same
6893 but nothing is reported. Removed blocks contribute nothing to
6894 `usage.input_tokens`. When streaming, the array is final in `message_start`;
6895 the final `message_delta` event carries it only when a server-side model
6896 fallback happened mid-stream, in which case it holds the serving model's
6897 entries and replaces the one in `message_start`.
6898
6899 - `path: string`
6900
6901 Where the removed block was in your request, as `messages.{i}.content.{j}`:
6902 `i` indexes the `messages` array you sent and `j` that message's `content`
6903 array — the same form error messages use.
6904
6905 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
6906
6907 Which binding check removed the block: `model_binding_mismatch` — it was
6908 created by a model whose reasoning the requested model may not read;
6909 `prefix_binding_mismatch` — the conversation before it differs from the
6910 conversation it was created in (the rest of that turn's consecutive thinking
6911 blocks are removed with it, each with this reason);
6912 `organization_binding_mismatch` — it was created under a different
6913 organization (an Anthropic organization, AWS account or Google Cloud project)
6914 and this organization is not one of its additional organizations;
6915 `end_user_binding_mismatch` — it was created for a different end user, or
6916 was removed by the consumer-organization binding. A block that would fail
6917 several checks reports one reason, in this order of precedence:
6918 `organization_binding_mismatch`, `end_user_binding_mismatch`,
6919 `model_binding_mismatch`, `prefix_binding_mismatch`.
6920
6921 - `"model_binding_mismatch"`
6922
6923 - `"prefix_binding_mismatch"`
6924
6925 - `"organization_binding_mismatch"`
6926
6927 - `"end_user_binding_mismatch"`
6928
6929 - `type: "thinking_dropped"`
6930
6931 Always `thinking_dropped` for this entry type.
6932
6933 default: thinking_dropped
6934
67956935 - `type: "succeeded"`
67966936
67976937 default: succeeded
from line 8258
81188258
81198259 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
81208260
8121 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
8261 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
81228262
81238263 The model that will complete your prompt.
81248264
81258265 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
81268266
8267 - `"claude-fable-5-1"`
8268
8269 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
8270
8271 - `"claude-mythos-5-1"`
8272
8273 Our most capable model for cybersecurity and biology research, available through trusted access programs
8274
81278275 - `"claude-sonnet-5"`
81288276
81298277 High-performance model for coding and agents
from line 8336
81888336
81898337 - `to: BetaFallbackInfo`
81908338
8191 The fallback model producing the content that follows this block. Its `model` is always the canonical id.
8192
8193 - `trigger: BetaFallbackRefusalTrigger`
8194
8195 What caused the `from` model to hand over at this hop.
8196
8197 - `category: "cyber" or "bio" or "frontier_llm" or 2 more or null`
8198
8199 The policy category that triggered a refusal.
8200
8201 - `"cyber"`
8202
8203 The request could enable cyber harm, such as malware or exploit development. Benign cybersecurity work can also trigger this category.
8204
8205 - `"bio"`
8206
8207 The request could enable biological harm, such as dangerous lab methods. Beneficial life sciences work can also trigger this category.
8208
8209 - `"frontier_llm"`
8210
8211 The request could assist the development of competing AI models, which is restricted under [Anthropic's commercial terms](https://www.anthropic.com/legal/commercial-terms). Benign machine learning work can also trigger this category.
8212
8213 - `"reasoning_extraction"`
8214
8215 The request asks the model to reproduce its internal reasoning in the response text. To get reasoning in a structured form instead, use [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/adaptive-thinking).
8216
8217 - `"general_harms"`
8218
8219 The request could be related to an area that was determined as harmful. Benign work might sometimes trigger this category.
8220
8221 - `type: "refusal"`
8222
8223 default: refusal
8224
8225 - `type: "fallback"`
8226
8227 default: fallback
8228
8229 - `context_management: BetaContextManagementResponse or null`
8230
8231 Context management response.
8232
8233 Information about context management strategies applied during the request.
8234
8235 - `applied_edits: array of BetaClearToolUses20250919EditResponse or BetaClearThinking20251015EditResponse`
8236
8237 List of context management edits that were applied.
8238
8239 - `BetaClearToolUses20250919EditResponse object`
8240
8241 - `cleared_input_tokens: number`
8242
8243 Number of input tokens cleared by this edit.
8244
8245 minimum: 0
8246
8247 - `cleared_tool_uses: number`
8248
8249 Number of tool uses that were cleared.
8250
8251 minimum: 0
8252
8253 - `type: "clear_tool_uses_20250919"`
8254
8255 The type of context management edit applied.
8256
8257 default: clear_tool_uses_20250919
8258
8259 - `BetaClearThinking20251015EditResponse object`
8260
8261 - `cleared_input_tokens: number`
8262
8263 Number of input tokens cleared by this edit.
8264
8265 minimum: 0
8266
8267 - `cleared_thinking_turns: number`
8268
8269 Number of thinking turns that were cleared.
8270
8271 minimum: 0
8272
8273 - `type: "clear_thinking_20251015"`
8274
8275 The type of context management edit applied.
8276
8277 default: clear_thinking_20251015
8278
8279 - `diagnostics: BetaDiagnostics or null`
8280
8281 Response envelope for request-level diagnostics. Present (possibly
8282 null) whenever the caller supplied `diagnostics` on the request.
8283
8284 - `cache_miss_reason: BetaCacheMissModelChanged or BetaCacheMissSystemChanged or BetaCacheMissToolsChanged or 3 more or null`
8285
8286 Explains why the prompt cache could not fully reuse the prefix from the request identified by `diagnostics.previous_message_id`. `null` means diagnosis is still pending — the response was serialized before the background comparison completed.
8287
8288 - `BetaCacheMissModelChanged object`
8289
8290 - `cache_missed_input_tokens: number`
8291
8292 Approximate number of input tokens that would have been read from cache had the prefix matched the previous request.
8293
8294 - `type: "model_changed"`
8295
8296 default: model_changed
8297
8298 - `BetaCacheMissSystemChanged object`
8299
8300 - `cache_missed_input_tokens: number`
8301
8302 Approximate number of input tokens that would have been read from cache had the prefix matched the previous request.
8303
8304 - `type: "system_changed"`
8305
8306 default: system_changed
8307
8308 - `BetaCacheMissToolsChanged object`
8309
8310 - `cache_missed_input_tokens: number`
8311
8312 Approximate number of input tokens that would have been read from cache had the prefix matched the previous request.
8313
8314 - `type: "tools_changed"`
8315
8316 default: tools_changed
8317
8318 - `BetaCacheMissMessagesChanged object`
8319
8320 - `cache_missed_input_tokens: number`
8321
8322 Approximate number of input tokens that would have been read from cache had the prefix matched the previous request.
8323
8324 - `type: "messages_changed"`
8325
8326 default: messages_changed
8327
8328 - `BetaCacheMissPreviousMessageNotFound object`
8329
8330 - `type: "previous_message_not_found"`
8331
8332 default: previous_message_not_found
8333
8334 - `BetaCacheMissUnavailable object`
8335
8336 - `type: "unavailable"`
8337
8338 default: unavailable
8339
8340 - `model: Model`
8341
8342 The model that will complete your prompt.
8343
8344 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
8345
8346 - `role: "assistant"`
8347
8348 Conversational role of the generated message.
8349
8350 This will always be `"assistant"`.
8351
8352 default: assistant
8353
8354 - `stop_details: BetaRefusalStopDetails or null`
8355
8356 Structured information about a refusal.
8357
8358 - `category: "cyber" or "bio" or "frontier_llm" or 2 more or null`
8359
8360 The policy category that triggered a refusal.
8361
8362 - `"cyber"`
8363
8364 The request could enable cyber harm, such as malware or exploit development. Benign cybersecurity work can also trigger this category.
8365
8366 - `"bio"`
8367
8368 The request could enable biological harm, such as dangerous lab methods. Beneficial life sciences work can also trigger this category.
8369
8370 - `"frontier_llm"`
8371
8372 The request could assist the development of competing AI models, which is restricted under [Anthropic's commercial terms](https://www.anthropic.com/legal/commercial-terms). Benign machine learning work can also trigger this category.
8373
8374 - `"reasoning_extraction"`
8375
8376 The request asks the model to reproduce its internal reasoning in the response text. To get reasoning in a structured form instead, use [adaptive thinking](https://platform.claude.com/docs/en/build-with-claude/adaptive-thinking
8339 The fallback model produ
api/beta/messages/batches/cancel Changed · +7 / -1 lines
from line 22
2222
2323 - `string`
2424
25 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
25 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2626
2727 - `"message-batches-2024-09-24"`
2828
from line 105
105105 - `"thinking-display-updates-2026-08-18"`
106106
107107 - `"ce-user-management-2026-07-13"`
108
109 - `"mid-conversation-output-config-2026-07-01"`
110
111 - `"thinking-binding-controls-2026-08-01"`
112
113 - `"mid-conversation-system-clear-at-2026-08-21"`
108114
109115## Returns
110116
api/beta/messages/batches/create Changed · +70 / -22 lines
from line 16
1616
1717 - `string`
1818
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2020
2121 - `"message-batches-2024-09-24"`
2222
from line 100
100100
101101 - `"ce-user-management-2026-07-13"`
102102
103 - `"mid-conversation-output-config-2026-07-01"`
104
105 - `"thinking-binding-controls-2026-08-01"`
106
107 - `"mid-conversation-system-clear-at-2026-08-21"`
108
103109- `"anthropic-user-profile-id": optional string`
104110
105111 The user profile ID to attribute the requests in this batch to. Use when acting on behalf of a party other than your organization. Requires the `user-profiles` beta header. Applies to every request in the batch; an individual request whose `user_profile_id` body field conflicts with this header is errored.
from line 1418
14121418
14131419 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
14141420
1415 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
1421 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
14161422
14171423 The model that will complete your prompt.
14181424
14191425 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
14201426
1427 - `"claude-fable-5-1"`
1428
1429 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
1430
1431 - `"claude-mythos-5-1"`
1432
1433 Our most capable model for cybersecurity and biology research, available through trusted access programs
1434
14211435 - `"claude-sonnet-5"`
14221436
14231437 High-performance model for coding and agents
from line 1512
14981512
14991513 - `"system"`
15001514
1515 - `clear_at: optional "next_user_message" or "never" or null`
1516
1517 How long this system message's text stays in front of the model. `"never"` (the default) renders it on every request that includes it. `"next_user_message"` renders it only for the user turn it follows: once a later `role: "user"` message exists in `messages` the message stays in the array (send it unchanged) but is no longer shown to the model. Only permitted on `role: "system"` messages.
1518
1519 - `"next_user_message"`
1520
1521 - `"never"`
1522
1523 - `output_config: optional BetaSystemMessageOutputConfig or null`
1524
1525 Per-message output configuration on a role:"system" input message.
1526
1527 Fields here apply per-turn; `format` remains top-level only. An
1528 empty `{}` is accepted on a message that carries content; a message
1529 with neither content nor output_config fields is rejected.
1530
1531 - `effort: optional "low" or "medium" or "high" or 2 more or null`
1532
1533 All possible effort levels.
1534
1535 - `"low"`
1536
1537 - `"medium"`
1538
1539 - `"high"`
1540
1541 - `"xhigh"`
1542
1543 - `"max"`
1544
15011545 - `model: Model`
15021546
15031547 The model that will complete your prompt.
from line 1844
18001844
18011845 - `type: "enabled"`
18021846
1847 - `block_binding: optional BetaThinkingBlockBinding or null`
1848
1849 Controls for block binding: what happens when a thinking block this
1850 request sends back fails the conversation check. Every field is optional;
1851 an empty object means every default.
1852
1853 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
1854
1855 What happens when a thinking block in `messages` fails the conversation
1856 check: it was created in a different conversation, or the messages before
1857 it have changed since. `"error"` (the default) fails the request with a
1858 400 error. `"drop_block"` removes the failing blocks and the request
1859 proceeds; the model no longer sees the dropped reasoning.
1860
1861 - `"error"`
1862
1863 - `"drop_block"`
1864
18031865 - `display: optional "summarized" or "omitted" or "updates" or null`
18041866
18051867 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 1880
18181880
18191881 - `type: "adaptive"`
18201882
1883 - `block_binding: optional BetaThinkingBlockBinding or null`
1884
1885 Controls for block binding: what happens when a thinking block this
1886 request sends back fails the conversation check. Every field is optional;
1887 an empty object means every default.
1888
18211889 - `display: optional "summarized" or "omitted" or "updates" or null`
18221890
18231891 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 2387
23192387
23202388 - `type: "browser_toolset_20260801"`
23212389
2322 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2323
2324 - `"direct"`
2325
2326 - `"code_execution_20250825"`
2327
2328 - `"code_execution_20260120"`
2329
2330 - `"code_execution_20260521"`
2331
23322390 - `cache_control: optional BetaCacheControlEphemeral or null`
23332391
23342392 Create a cache control breakpoint at this content block.
from line 3012
29543012 via `configs.zoom.enabled`.
29553013
29563014 - `type: "computer_toolset_20260801"`
2957
2958 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2959
2960 - `"direct"`
2961
2962 - `"code_execution_20250825"`
2963
2964 - `"code_execution_20260120"`
2965
2966 - `"code_execution_20260521"`
29673015
29683016 - `cache_control: optional BetaCacheControlEphemeral or null`
29693017
api/beta/messages/batches/delete Changed · +7 / -1 lines
from line 22
2222
2323 - `string`
2424
25 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
25 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2626
2727 - `"message-batches-2024-09-24"`
2828
from line 105
105105 - `"thinking-display-updates-2026-08-18"`
106106
107107 - `"ce-user-management-2026-07-13"`
108
109 - `"mid-conversation-output-config-2026-07-01"`
110
111 - `"thinking-binding-controls-2026-08-01"`
112
113 - `"mid-conversation-system-clear-at-2026-08-21"`
108114
109115## Returns
110116
api/beta/messages/batches/list Changed · +7 / -1 lines
from line 32
3232
3333 - `string`
3434
35 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
35 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
3636
3737 - `"message-batches-2024-09-24"`
3838
from line 115
115115 - `"thinking-display-updates-2026-08-18"`
116116
117117 - `"ce-user-management-2026-07-13"`
118
119 - `"mid-conversation-output-config-2026-07-01"`
120
121 - `"thinking-binding-controls-2026-08-01"`
122
123 - `"mid-conversation-system-clear-at-2026-08-21"`
118124
119125## Returns
120126
api/beta/messages/batches/results Changed · +70 / -2 lines
from line 22
2222
2323 - `string`
2424
25 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
25 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2626
2727 - `"message-batches-2024-09-24"`
2828
from line 106
106106
107107 - `"ce-user-management-2026-07-13"`
108108
109 - `"mid-conversation-output-config-2026-07-01"`
110
111 - `"thinking-binding-controls-2026-08-01"`
112
113 - `"mid-conversation-system-clear-at-2026-08-21"`
114
109115## Returns
110116
111117- `BetaMessageBatchIndividualResponse object`
from line 1055
10491055
10501056 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
10511057
1052 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
1058 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
10531059
10541060 The model that will complete your prompt.
10551061
10561062 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
10571063
1064 - `"claude-fable-5-1"`
1065
1066 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
1067
1068 - `"claude-mythos-5-1"`
1069
1070 Our most capable model for cybersecurity and biology research, available through trusted access programs
1071
10581072 - `"claude-sonnet-5"`
10591073
10601074 High-performance model for coding and agents
from line 1799
17851799 - `"standard"`
17861800
17871801 - `"fast"`
1802
1803 - `input_transformations: optional array of BetaThinkingDroppedInputTransformation or null`
1804
1805 Changes the API made to the request's input before showing it to the model:
1806 one entry per change, in request order. Today the only entry type is
1807 `thinking_dropped` — a `thinking`, `redacted_thinking` or `connector_text`
1808 block from the request's `messages` that was removed from the prompt instead
1809 of being shown to the model because it failed a binding check. More entry
1810 types may be added over time; ignore types you do not recognize.
1811
1812 Requires `anthropic-beta: thinking-binding-controls-2026-08-01`. Present on
1813 every such response from a model that supports extended thinking, as `[]`
1814 when nothing was changed; without the beta, blocks are removed all the same
1815 but nothing is reported. Removed blocks contribute nothing to
1816 `usage.input_tokens`. When streaming, the array is final in `message_start`;
1817 the final `message_delta` event carries it only when a server-side model
1818 fallback happened mid-stream, in which case it holds the serving model's
1819 entries and replaces the one in `message_start`.
1820
1821 - `path: string`
1822
1823 Where the removed block was in your request, as `messages.{i}.content.{j}`:
1824 `i` indexes the `messages` array you sent and `j` that message's `content`
1825 array — the same form error messages use.
1826
1827 - `reason: "model_binding_mismatch" or "prefix_binding_mismatch" or "organization_binding_mismatch" or "end_user_binding_mismatch"`
1828
1829 Which binding check removed the block: `model_binding_mismatch` — it was
1830 created by a model whose reasoning the requested model may not read;
1831 `prefix_binding_mismatch` — the conversation before it differs from the
1832 conversation it was created in (the rest of that turn's consecutive thinking
1833 blocks are removed with it, each with this reason);
1834 `organization_binding_mismatch` — it was created under a different
1835 organization (an Anthropic organization, AWS account or Google Cloud project)
1836 and this organization is not one of its additional organizations;
1837 `end_user_binding_mismatch` — it was created for a different end user, or
1838 was removed by the consumer-organization binding. A block that would fail
1839 several checks reports one reason, in this order of precedence:
1840 `organization_binding_mismatch`, `end_user_binding_mismatch`,
1841 `model_binding_mismatch`, `prefix_binding_mismatch`.
1842
1843 - `"model_binding_mismatch"`
1844
1845 - `"prefix_binding_mismatch"`
1846
1847 - `"organization_binding_mismatch"`
1848
1849 - `"end_user_binding_mismatch"`
1850
1851 - `type: "thinking_dropped"`
1852
1853 Always `thinking_dropped` for this entry type.
1854
1855 default: thinking_dropped
17881856
17891857 - `type: "succeeded"`
17901858
api/beta/messages/batches/retrieve Changed · +7 / -1 lines
from line 20
2020
2121 - `string`
2222
23 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
23 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2424
2525 - `"message-batches-2024-09-24"`
2626
from line 103
103103 - `"thinking-display-updates-2026-08-18"`
104104
105105 - `"ce-user-management-2026-07-13"`
106
107 - `"mid-conversation-output-config-2026-07-01"`
108
109 - `"thinking-binding-controls-2026-08-01"`
110
111 - `"mid-conversation-system-clear-at-2026-08-21"`
106112
107113## Returns
108114
api/beta/messages/count_tokens Changed · +70 / -22 lines
from line 16
1616
1717 - `string`
1818
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 38 more`
19 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 41 more`
2020
2121 - `"message-batches-2024-09-24"`
2222
from line 100
100100
101101 - `"ce-user-management-2026-07-13"`
102102
103 - `"mid-conversation-output-config-2026-07-01"`
104
105 - `"thinking-binding-controls-2026-08-01"`
106
107 - `"mid-conversation-system-clear-at-2026-08-21"`
108
103109- `"anthropic-user-profile-id": optional string`
104110
105111 The user profile ID to attribute this request to. Use when acting on behalf of a party other than your organization. Requires the `user-profiles` beta header.
from line 1386
13801386
13811387 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
13821388
1383 - `"claude-sonnet-5" or "claude-fable-5" or "claude-mythos-5" or 12 more`
1389 - `"claude-fable-5-1" or "claude-mythos-5-1" or "claude-sonnet-5" or 14 more`
13841390
13851391 The model that will complete your prompt.
13861392
13871393 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
13881394
1395 - `"claude-fable-5-1"`
1396
1397 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
1398
1399 - `"claude-mythos-5-1"`
1400
1401 Our most capable model for cybersecurity and biology research, available through trusted access programs
1402
13891403 - `"claude-sonnet-5"`
13901404
13911405 High-performance model for coding and agents
from line 1480
14661480
14671481 - `"system"`
14681482
1483 - `clear_at: optional "next_user_message" or "never" or null`
1484
1485 How long this system message's text stays in front of the model. `"never"` (the default) renders it on every request that includes it. `"next_user_message"` renders it only for the user turn it follows: once a later `role: "user"` message exists in `messages` the message stays in the array (send it unchanged) but is no longer shown to the model. Only permitted on `role: "system"` messages.
1486
1487 - `"next_user_message"`
1488
1489 - `"never"`
1490
1491 - `output_config: optional BetaSystemMessageOutputConfig or null`
1492
1493 Per-message output configuration on a role:"system" input message.
1494
1495 Fields here apply per-turn; `format` remains top-level only. An
1496 empty `{}` is accepted on a message that carries content; a message
1497 with neither content nor output_config fields is rejected.
1498
1499 - `effort: optional "low" or "medium" or "high" or 2 more or null`
1500
1501 All possible effort levels.
1502
1503 - `"low"`
1504
1505 - `"medium"`
1506
1507 - `"high"`
1508
1509 - `"xhigh"`
1510
1511 - `"max"`
1512
14691513- `model: Model`
14701514
14711515 The model that will complete your prompt.
from line 1748
17041748
17051749 - `type: "enabled"`
17061750
1751 - `block_binding: optional BetaThinkingBlockBinding or null`
1752
1753 Controls for block binding: what happens when a thinking block this
1754 request sends back fails the conversation check. Every field is optional;
1755 an empty object means every default.
1756
1757 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
1758
1759 What happens when a thinking block in `messages` fails the conversation
1760 check: it was created in a different conversation, or the messages before
1761 it have changed since. `"error"` (the default) fails the request with a
1762 400 error. `"drop_block"` removes the failing blocks and the request
1763 proceeds; the model no longer sees the dropped reasoning.
1764
1765 - `"error"`
1766
1767 - `"drop_block"`
1768
17071769 - `display: optional "summarized" or "omitted" or "updates" or null`
17081770
17091771 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 1784
17221784
17231785 - `type: "adaptive"`
17241786
1787 - `block_binding: optional BetaThinkingBlockBinding or null`
1788
1789 Controls for block binding: what happens when a thinking block this
1790 request sends back fails the conversation check. Every field is optional;
1791 an empty object means every default.
1792
17251793 - `display: optional "summarized" or "omitted" or "updates" or null`
17261794
17271795 Controls how thinking content appears in the response. When set to `summarized`, thinking is returned normally. When set to `omitted`, thinking content is redacted but a signature is returned for multi-turn continuity. Defaults to `summarized`.
from line 2181
21132181
21142182 - `type: "browser_toolset_20260801"`
21152183
2116 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2117
2118 - `"direct"`
2119
2120 - `"code_execution_20250825"`
2121
2122 - `"code_execution_20260120"`
2123
2124 - `"code_execution_20260521"`
2125
21262184 - `cache_control: optional BetaCacheControlEphemeral or null`
21272185
21282186 Create a cache control breakpoint at this content block.
from line 2806
27482806 via `configs.zoom.enabled`.
27492807
27502808 - `type: "computer_toolset_20260801"`
2751
2752 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
2753
2754 - `"direct"`
2755
2756 - `"code_execution_20250825"`
2757
2758 - `"code_execution_20260120"`
2759
2760 - `"code_execution_20260521"`
27612809
27622810 - `cache_control: optional BetaCacheControlEphemeral or null`
27632811