Create a Message changedapi/beta/messages/create
Nearest release: v2.1.283, published 3 hours after this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Recorded here
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Lines−244removed
From line
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from line 243
243243
244244 - `document_title: string or null`
245245
246 maxLength: 500, minLength: 1
246 minLength: 1, maxLength: 500
247247
248248 - `end_char_index: number`
249249
from line 263
263263
264264 - `document_title: string or null`
265265
266 maxLength: 500, minLength: 1
266 minLength: 1, maxLength: 500
267267
268268 - `end_page_number: number`
269269
from line 287
287287
288288 - `document_title: string or null`
289289
290 maxLength: 500, minLength: 1
290 minLength: 1, maxLength: 500
291291
292292 - `end_block_index: number`
293293
from line 311
311311
312312 - `title: string or null`
313313
314 maxLength: 512, minLength: 1
314 minLength: 1, maxLength: 512
315315
316316 - `url: string`
317317
from line 467
467467
468468 - `title: optional string or null`
469469
470 maxLength: 500, minLength: 1
470 minLength: 1, maxLength: 500
471471
472472 - `BetaSearchResultBlockParam object`
473473
from line 531
531531
532532 - `name: string`
533533
534 maxLength: 200, minLength: 1
534 minLength: 1, maxLength: 200
535535
536536 - `cache_control: optional BetaCacheControlEphemeral or null`
537537
from line 567
567567
568568 For a toolset member tool_use, the toolset family this member belongs to.
569569
570 maxLength: 64, minLength: 1, pattern: ^[a-zA-Z0-9_-]+$
570 minLength: 1, maxLength: 64, pattern: ^[a-zA-Z0-9_-]+$
571571
572572 - `BetaToolResultBlockParam object`
573573
from line 603
603603
604604 - `tool_name: string`
605605
606 maxLength: 256, minLength: 1, pattern: ^[a-zA-Z0-9_-]{1,256}$
606 minLength: 1, maxLength: 256, pattern: ^[a-zA-Z0-9_-]{1,256}$
607607
608608 - `cache_control: optional BetaCacheControlEphemeral or null`
609609
from line 631
631631
632632 The caller-assigned identifier for this tab, unique within the inventory.
633633
634 maxLength: 4096, minLength: 1, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
634 minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
635635
636636 - `title: string`
637637
from line 657
657657
658658 Tabs opened and download state changes during this call. "Nothing to report" is expressed by omitting the field, never by an empty list.
659659
660 maxItems: 200, minItems: 1
660 minItems: 1, maxItems: 200
661661
662662 - `BetaBrowserStateChangeTabOpened object`
663663
from line 675
675675
676676 The `tab_id` of the opened tab, present in `tabs`.
677677
678 maxLength: 4096, minLength: 1, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
678 minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
679679
680680 - `BetaBrowserStateChangeDownloadStarted object`
681681
from line 687
687687
688688 The caller-assigned identifier for this download, stable across the state changes reporting it.
689689
690 maxLength: 4096, minLength: 1, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
690 minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
691691
692692 - `url: string`
693693
from line 708
708708
709709 The caller-assigned identifier for this download, stable across the state changes reporting it.
710710
711 maxLength: 4096, minLength: 1, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
711 minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
712712
713713 - `url: string`
714714
from line 720
720720
721721 Where the executor saved the file, on the executor's filesystem. Only included when another tool in the same environment can read the file at that path.
722722
723 pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$, maxLength: 4096
723 maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
724724
725725 - `size_bytes: optional number or null`
726726
from line 738
738738
739739 The caller-assigned identifier for this download, stable across the state changes reporting it.
740740
741 maxLength: 4096, minLength: 1, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
741 minLength: 1, maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
742742
743743 - `url: string`
744744
from line 750
750750
751751 The failure or cancellation detail, when known.
752752
753 pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$, maxLength: 4096
753 maxLength: 4096, pattern: ^[^\x00-\x1f\x7f-\x9f\u2028\u2029]*$
754754
755755 - `is_error: optional boolean`
756756
from line 758
758758
759759 For a toolset member tool_result, the toolset family of the paired tool_use.
760760
761 maxLength: 64, minLength: 1, pattern: ^[a-zA-Z0-9_-]+$
761 minLength: 1, maxLength: 64, pattern: ^[a-zA-Z0-9_-]+$
762762
763763 - `BetaServerToolUseBlockParam object`
764764
from line 1190
11901190
11911191 - `tool_name: string`
11921192
1193 maxLength: 256, minLength: 1, pattern: ^[a-zA-Z0-9_-]{1,256}$
1193 minLength: 1, maxLength: 256, pattern: ^[a-zA-Z0-9_-]{1,256}$
11941194
11951195 - `cache_control: optional BetaCacheControlEphemeral or null`
11961196
from line 1382
13821382
13831383 This is how the tool will be called by the model and in `tool_use` blocks.
13841384
1385 maxLength: 128, minLength: 1, pattern: ^[a-zA-Z0-9_-]{1,128}$
1385 minLength: 1, maxLength: 128, pattern: ^[a-zA-Z0-9_-]{1,128}$
13861386
13871387 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
13881388
from line 1633
16331633
16341634 - `configs: optional BetaBrowserToolsetConfigs or null`
16351635
1636 Per-member configuration for `browser_toolset_20260801`: one
1637 optional field per member tool, keyed by the member name — the same
1638 name the member's `tool_use` blocks carry. Every member is an
1639 accepted key, and a member's defaults apply wherever its key is
1640 absent. Unknown keys are rejected: the field set is this toolset
1641 version's complete member set.
1636 Sparse per-member overrides, keyed by member name. Absent, null, and {} are equivalent; a member's defaults apply wherever its key is absent.
16421637
16431638 - `type: optional BetaBrowserTypeConfig or null`
16441639
from line 2254
22592254
22602255 - `configs: optional BetaComputerToolsetConfigs or null`
22612256
2262 Per-member configuration for `computer_toolset_20260801`: one
2263 optional field per member tool, keyed by the member name — the same
2264 name the member's `tool_use` blocks carry. Every member is an
2265 accepted key, and a member's defaults apply wherever its key is
2266 absent. Unknown keys are rejected: the field set is this toolset
2267 version's complete member set.
2257 Sparse per-member overrides, keyed by member name. Absent, null, and {} are equivalent; a member's defaults apply wherever its key is absent.
22682258
22692259 - `type: optional BetaComputerTypeConfig or null`
22702260
from line 2608
26182608
26192609 Maximum number of times the tool can be used in the API request.
26202610
2621 exclusiveMinimum: 0
2611 minimum: 1
26222612
26232613 - `strict: optional boolean`
26242614
from line 2624
26342624
26352625 The city of the user.
26362626
2637 maxLength: 255, minLength: 1
2627 minLength: 1, maxLength: 255
26382628
26392629 - `country: optional string or null`
26402630
26412631 The two letter [ISO country code](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) of the user.
26422632
2643 maxLength: 2, minLength: 2
2633 minLength: 2, maxLength: 2
26442634
26452635 - `region: optional string or null`
26462636
26472637 The region of the user.
26482638
2649 maxLength: 255, minLength: 1
2639 minLength: 1, maxLength: 255
26502640
26512641 - `timezone: optional string or null`
26522642
26532643 The [IANA timezone](https://nodatime.org/TimeZones) of the user.
26542644
2655 maxLength: 255, minLength: 1
2645 minLength: 1, maxLength: 255
26562646
26572647 - `BetaWebFetchTool20250910 object`
26582648
from line 2688
26982688
26992689 Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.
27002690
2701 exclusiveMinimum: 0
2691 minimum: 1
27022692
27032693 - `max_uses: optional number or null`
27042694
27052695 Maximum number of times the tool can be used in the API request.
27062696
2707 exclusiveMinimum: 0
2697 minimum: 1
27082698
27092699 - `strict: optional boolean`
27102700
from line 2702
27122702
27132703 - `url_sources: optional BetaWebFetchURLSources or null`
27142704
2715 Which sources contribute to the set of URLs web fetch may fetch.
2705 Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.
27162706
2717 Each key is a tagged variant: `user_input` is `all` or `none`; the
2718 two tool filters are `all`, `none`, `only` (only the named tools'
2719 results) or `except` (every result but the named tools'). A named tool
2720 must be declared in this request's `tools[]`.
2721
27222707 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`
27232708
27242709 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].
from line 2826
28412826
28422827 Maximum number of times the tool can be used in the API request.
28432828
2844 exclusiveMinimum: 0
2829 minimum: 1
28452830
28462831 - `strict: optional boolean`
28472832
from line 2880
28952880
28962881 Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.
28972882
2898 exclusiveMinimum: 0
2883 minimum: 1
28992884
29002885 - `max_uses: optional number or null`
29012886
29022887 Maximum number of times the tool can be used in the API request.
29032888
2904 exclusiveMinimum: 0
2889 minimum: 1
29052890
29062891 - `strict: optional boolean`
29072892
from line 2894
29092894
29102895 - `url_sources: optional BetaWebFetchURLSources or null`
29112896
2912 Which sources contribute to the set of URLs web fetch may fetch.
2897 Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.
29132898
2914 Each key is a tagged variant: `user_input` is `all` or `none`; the
2915 two tool filters are `all`, `none`, `only` (only the named tools'
2916 results) or `except` (every result but the named tools'). A named tool
2917 must be declared in this request's `tools[]`.
2918
29192899 - `BetaWebFetchTool20260309 object`
29202900
29212901 Web fetch tool with use_cache parameter for bypassing cached content.
from line 2942
29622942
29632943 Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.
29642944
2965 exclusiveMinimum: 0
2945 minimum: 1
29662946
29672947 - `max_uses: optional number or null`
29682948
29692949 Maximum number of times the tool can be used in the API request.
29702950
2971 exclusiveMinimum: 0
2951 minimum: 1
29722952
29732953 - `strict: optional boolean`
29742954
from line 2956
29762956
29772957 - `url_sources: optional BetaWebFetchURLSources or null`
29782958
2979 Which sources contribute to the set of URLs web fetch may fetch.
2959 Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.
29802960
2981 Each key is a tagged variant: `user_input` is `all` or `none`; the
2982 two tool filters are `all`, `none`, `only` (only the named tools'
2983 results) or `except` (every result but the named tools'). A named tool
2984 must be declared in this request's `tools[]`.
2985
29862961 - `use_cache: optional boolean`
29872962
29882963 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.
from line 3002
30273002
30283003 Maximum number of times the tool can be used in the API request.
30293004
3030 exclusiveMinimum: 0
3005 minimum: 1
30313006
30323007 - `response_inclusion: optional "full" or "excluded"`
30333008
from line 3064
30893064
30903065 Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.
30913066
3092 exclusiveMinimum: 0
3067 minimum: 1
30933068
30943069 - `max_uses: optional number or null`
30953070
30963071 Maximum number of times the tool can be used in the API request.
30973072
3098 exclusiveMinimum: 0
3073 minimum: 1
30993074
31003075 - `response_inclusion: optional "full" or "excluded"`
31013076
from line 3086
31113086
31123087 - `url_sources: optional BetaWebFetchURLSources or null`
31133088
3114 Which sources contribute to the set of URLs web fetch may fetch.
3089 Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.
31153090
3116 Each key is a tagged variant: `user_input` is `all` or `none`; the
3117 two tool filters are `all`, `none`, `only` (only the named tools'
3118 results) or `except` (every result but the named tools'). A named tool
3119 must be declared in this request's `tools[]`.
3120
31213091 - `use_cache: optional boolean`
31223092
31233093 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.
from line 3102
31323102
31333103 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
31343104
3105 - `string`
3106
31353107 - `"claude-fable-5-1" or "claude-opus-5-5" or "claude-mythos-5-1" or 15 more`
31363108
31373109 The model that will complete your prompt.
from line 3146
31743146
31753147 Powerful intelligence for long-running agents and coding
31763148
3177 - `"claude-mythos-preview"`
3178
3179 New class of intelligence, strongest in coding and cybersecurity
3180
31813149 - `"claude-opus-4-6"`
31823150
31833151 Powerful intelligence for long-running agents and coding
from line 3178
32103178
32113179 High-performance model for agents and coding
32123180
3213 - `string`
3181 - `"claude-mythos-preview"`
32143182
3183 **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.anthropic.com/en/docs/resources/model-deprecations for more information.
3184
3185 New class of intelligence, strongest in coding and cybersecurity
3186
32153187 - `name: "advisor"`
32163188
32173189 Name of the tool.
from line 3222
32503222
32513223 Maximum number of times the tool can be used in the API request.
32523224
3253 exclusiveMinimum: 0
3225 minimum: 1
32543226
32553227 - `strict: optional boolean`
32563228
from line 3313
33413313
33423314 Name of the MCP server to configure tools for
33433315
3344 maxLength: 255, minLength: 1
3316 minLength: 1, maxLength: 255
33453317
33463318 - `cache_control: optional BetaCacheControlEphemeral or null`
33473319
from line 3423
34513423
34523424 The name of the MCP server this listing came from, as `mcp_servers` declares it.
34533425
3454 maxLength: 255, minLength: 1
3426 minLength: 1, maxLength: 255
34553427
34563428 - `tools: array of BetaMCPToolParam`
34573429
from line 3505
35333505
35343506 - `effort: optional "low" or "medium" or "high" or 2 more or null`
35353507
3536 All possible effort levels.
3508 How much effort the model should put into its response. Higher effort levels may result in more thorough analysis but take longer.
35373509
3510 Valid values are `low`, `medium`, `high`, `xhigh`, or `max`.
3511
35383512 - `"low"`
35393513
35403514 - `"medium"`
from line 3531
35573531
35583532- `compaction: optional BetaCompactionConfig or null`
35593533
3560 Compact the whole conversation and return a signed `compaction` block,
3561 alone, that a later request sends back first in `messages`, in place of
3562 the messages it summarizes. There is no trigger and no pause flag: sending
3563 the parameter compacts, and nothing is sampled after the block.
3534 Compaction configuration.
35643535
3565 The summarization prompt is the server's own unless `instructions` are
3566 given, which then replace it for this request; a value that is empty or
3567 only whitespace counts as absent.
3536 When set on `POST /v1/messages`, the request is a compaction request: the conversation in `messages` is summarized and the response holds only the resulting `compaction` block (`stop_reason` `"compaction"`), which later requests send first in `messages` in place of the messages it summarizes. `POST /v1/messages/count_tokens` accepts this parameter and ignores it: the count it returns is for the conversation in `messages` as sent. Cannot be combined with `context_management`.
35683537
35693538 - `type: "summarize"`
35703539
from line 3573
36043573
36053574 Skill ID
36063575
3607 maxLength: 64, minLength: 1
3576 minLength: 1, maxLength: 64
36083577
36093578 - `version: optional string`
36103579
36113580 Skill version or 'latest' for most recent version
36123581
3613 maxLength: 64, minLength: 1
3582 minLength: 1, maxLength: 64
36143583
36153584 - `string`
36163585
from line 3593
36243593
36253594 List of context management edits to apply
36263595
3627 minItems: 0
3628
36293596 - `BetaClearToolUses20250919Edit object`
36303597
36313598 - `type: "clear_tool_uses_20250919"`
from line 3691
37243691
37253692- `diagnostics: optional BetaDiagnosticsParam or null`
37263693
3727 Request-level diagnostics. Currently carries the previous response
3728 id for prompt-cache divergence reporting.
3694 Request-level diagnostics. Supply `previous_message_id` to have the response include `diagnostics.cache_miss_reason` explaining any prompt-cache divergence from that prior request.
37293695
37303696 - `previous_message_id: optional string or null`
37313697
from line 3738
37723738
37733739 The opaque `fallback_credit_token` from a prior refusal's `stop_details` — the same string the bare-string form carries.
37743740
3775 maxLength: 2048, minLength: 1
3741 minLength: 1, maxLength: 2048
37763742
37773743 - `mode: optional "strict" or "best_effort"`
37783744
from line 3766
38003766
38013767 - `effort: optional "low" or "medium" or "high" or 2 more or null`
38023768
3803 All possible effort levels.
3769 How much effort the model should put into its response. Higher effort levels may result in more thorough analysis but take longer.
38043770
3771 Valid values are `low`, `medium`, `high`, `xhigh`, or `max`.
3772
38053773 - `"low"`
38063774
38073775 - `"medium"`
from line 3792
38243792
38253793 - `task_budget: optional BetaTokenTaskBudget or null`
38263794
3827 User-configurable total token budget across contexts.
3795 Configuration for token budget tracking across contexts.
38283796
38293797 - `type: "tokens"`
38303798
from line 3836
38683836
38693837 - `block_binding: optional BetaThinkingBlockBinding or null`
38703838
3871 Controls for block binding: what happens when a thinking block this
3872 request sends back fails the conversation check. Every field is optional;
3873 an empty object means every default.
3839 Controls for block binding: what happens when a thinking block this request sends back fails the conversation check. `null`, absent or an empty object means every default.
38743840
38753841 - `prefix_mismatch_behavior: optional BetaThinkingPrefixMismatchBehavior or null`
38763842
3877 What happens when a thinking block in `messages` fails the conversation
3878 check: it was created in a different conversation, or the messages before
3879 it have changed since. `"error"` (the default) fails the request with a
3880 400 error. `"drop_block"` removes the failing blocks and the request
3881 proceeds; the model no longer sees the dropped reasoning.
3843 "error" (default) | "drop_block". What happens when a thinking block in `messages` fails the conversation check (it was created in a different conversation, or the messages before it have changed since). "error" fails the request with a 400 error. "drop_block" removes the failing blocks and the request proceeds; each removal is reported in `input_transformations`.
38823844
38833845 - `"error"`
38843846
from line 3866
39043866
39053867 - `block_binding: optional BetaThinkingBlockBinding or null`
39063868
3907 Controls for block binding: what happens when a thinking block this
3908 request sends back fails the conversation check. Every field is optional;
3909 an empty object means every default.
3869 Controls for block binding: what happens when a thinking block this request sends back fails the conversation check. `null`, absent or an empty object means every default.
39103870
39113871 - `display: optional "summarized" or "omitted" or "updates" or null`
39123872
from line 3932
39723932
39733933- `speed: optional "standard" or "fast" or null`
39743934
3975 Inference speed mode. `fast` provides significantly faster output token generation at premium pricing. Not all models support `fast`; invalid combinations are rejected at create time.
3935 The inference speed mode for this request. `"fast"` enables high output-tokens-per-second inference.
39763936
39773937 - `"standard"`
39783938
from line 4201
42414201
42424202 Note that even with `temperature` of `0.0`, the results will not be fully deterministic.
42434203
4244 maximum: 1, minimum: 0
4204 minimum: 0, maximum: 1
42454205
42464206- `top_k: optional number`
42474207
from line 4225
42654225
42664226 Recommended for advanced use cases only.
42674227
4268 maximum: 1, minimum: 0
4228 minimum: 0, maximum: 1
42694229
42704230## Returns
42714231
from line 4247
42874247
42884248 - `container: BetaContainer or null`
42894249
4290 Information about the container used in the request (for the code execution tool)
4250 Information about the container used in this request.
42914251
4252 This will be non-null if a container tool (e.g. code execution) was used.
4253
42924254 - `id: string`
42934255
42944256 Identifier for the container used in this request
from line 4277
43154277
43164278 Skill ID
43174279
4318 maxLength: 64, minLength: 1
4280 minLength: 1, maxLength: 64
43194281
43204282 - `version: string`
43214283
43224284 The resolved version: a skill version ID for custom skills.
43234285
4324 maxLength: 64, minLength: 1
4286 minLength: 1, maxLength: 64
43254287
43264288 - `content: array of BetaContentBlock`
43274289
from line 4456
44944456
44954457 - `text: string`
44964458
4497 minLength: 0
4498
44994459 - `BetaThinkingBlock object`
45004460
45014461 - `type: "thinking"`
from line 4534
45744534
45754535 For a toolset member tool_use, the toolset family.
45764536
4577 maxLength: 64, minLength: 1, pattern: ^[a-zA-Z0-9_-]+$
4537 minLength: 1, maxLength: 64, pattern: ^[a-zA-Z0-9_-]+$
45784538
45794539 - `BetaServerToolUseBlock object`
45804540
from line 5038
50785038
50795039 - `tool_name: string`
50805040
5081 maxLength: 256, minLength: 1, pattern: ^[a-zA-Z0-9_-]{1,256}$
5041 minLength: 1, maxLength: 256, pattern: ^[a-zA-Z0-9_-]{1,256}$
50825042
50835043 - `tool_use_id: string`
50845044
from line 5088
51285088
51295089 - `text: string`
51305090
5131 minLength: 0
5132
51335091 - `is_error: boolean`
51345092
51355093 default: false
from line 5225
52675225
52685226 This is how the tool will be called by the model and in `tool_use` blocks.
52695227
5270 maxLength: 128, minLength: 1, pattern: ^[a-zA-Z0-9_-]{1,128}$
5228 minLength: 1, maxLength: 128, pattern: ^[a-zA-Z0-9_-]{1,128}$
52715229
52725230 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
52735231
from line 5489
55315489
55325490 - `configs: optional BetaBrowserToolsetConfigs or null`
55335491
5534 Per-member configuration for `browser_toolset_20260801`: one
5535 optional field per member tool, keyed by the member name — the same
5536 name the member's `tool_use` blocks carry. Every member is an
5537 accepted key, and a member's defaults apply wherever its key is
5538 absent. Unknown keys are rejected: the field set is this toolset
5539 version's complete member set.
5492 Sparse per-member overrides, keyed by member name. Absent, null, and {} are equivalent; a member's defaults apply wherever its key is absent.
55405493
55415494 - `type: optional BetaBrowserTypeConfig or null`
55425495
from line 6110
61576110
61586111 - `configs: optional BetaComputerToolsetConfigs or null`
61596112
6160 Per-member configuration for `computer_toolset_20260801`: one
6161 optional field per member tool, keyed by the member name — the same
6162 name the member's `tool_use` blocks carry. Every member is an
6163 accepted key, and a member's defaults apply wherever its key is
6164 absent. Unknown keys are rejected: the field set is this toolset
6165 version's complete member set.
6113 Sparse per-member overrides, keyed by member name. Absent, null, and {} are equivalent; a member's defaults apply wherever its key is absent.
61666114
61676115 - `type: optional BetaComputerTypeConfig or null`
61686116
from line 6464
65166464
65176465 Maximum number of times the tool can be used in the API request.
65186466
6519 exclusiveMinimum: 0
6467 minimum: 1
65206468
65216469 - `strict: optional boolean`
65226470
from line 6480
65326480
65336481 The city of the user.
65346482
6535 maxLength: 255, minLength: 1
6483 minLength: 1, maxLength: 255
65366484
65376485 - `country: optional string or null`
65386486
65396487 The two letter [ISO country code](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2) of the user.
65406488
6541 maxLength: 2, minLength: 2
6489 minLength: 2, maxLength: 2
65426490
65436491 - `region: optional string or null`
65446492
65456493 The region of the user.
65466494
6547 maxLength: 255, minLength: 1
6495 minLength: 1, maxLength: 255
65486496
65496497 - `timezone: optional string or null`
65506498
65516499 The [IANA timezone](https://nodatime.org/TimeZones) of the user.
65526500
6553 maxLength: 255, minLength: 1
6501 minLength: 1, maxLength: 255
65546502
65556503 - `BetaWebFetchTool20250910 object`
65566504
from line 6546
65986546
65996547 Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.
66006548
6601 exclusiveMinimum: 0
6549 minimum: 1
66026550
66036551 - `max_uses: optional number or null`
66046552
66056553 Maximum number of times the tool can be used in the API request.
66066554
6607 exclusiveMinimum: 0
6555 minimum: 1
66086556
66096557 - `strict: optional boolean`
66106558
from line 6560
66126560
66136561 - `url_sources: optional BetaWebFetchURLSources or null`
66146562
6615 Which sources contribute to the set of URLs web fetch may fetch.
6563 Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.
66166564
6617 Each key is a tagged variant: `user_input` is `all` or `none`; the
6618 two tool filters are `all`, `none`, `only` (only the named tools'
6619 results) or `except` (every result but the named tools'). A named tool
6620 must be declared in this request's `tools[]`.
6621
66226565 - `client_tool_results: optional BetaWebFetchURLSourceAll or BetaWebFetchURLSourceNone or BetaWebFetchURLSourceOnly or BetaWebFetchURLSourceExcept`
66236566
66246567 Which client tools' results contribute fetchable URLs: "all", "none", or an only or except list of client tool names from tools[].
from line 6684
67416684
67426685 Maximum number of times the tool can be used in the API request.
67436686
6744 exclusiveMinimum: 0
6687 minimum: 1
67456688
67466689 - `strict: optional boolean`
67476690
from line 6738
67956738
67966739 Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.
67976740
6798 exclusiveMinimum: 0
6741 minimum: 1
67996742
68006743 - `max_uses: optional number or null`
68016744
68026745 Maximum number of times the tool can be used in the API request.
68036746
6804 exclusiveMinimum: 0
6747 minimum: 1
68056748
68066749 - `strict: optional boolean`
68076750
from line 6752
68096752
68106753 - `url_sources: optional BetaWebFetchURLSources or null`
68116754
6812 Which sources contribute to the set of URLs web fetch may fetch.
6755 Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.
68136756
6814 Each key is a tagged variant: `user_input` is `all` or `none`; the
6815 two tool filters are `all`, `none`, `only` (only the named tools'
6816 results) or `except` (every result but the named tools'). A named tool
6817 must be declared in this request's `tools[]`.
6818
68196757 - `BetaWebFetchTool20260309 object`
68206758
68216759 Web fetch tool with use_cache parameter for bypassing cached content.
from line 6800
68626800
68636801 Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.
68646802
6865 exclusiveMinimum: 0
6803 minimum: 1
68666804
68676805 - `max_uses: optional number or null`
68686806
68696807 Maximum number of times the tool can be used in the API request.
68706808
6871 exclusiveMinimum: 0
6809 minimum: 1
68726810
68736811 - `strict: optional boolean`
68746812
from line 6814
68766814
68776815 - `url_sources: optional BetaWebFetchURLSources or null`
68786816
6879 Which sources contribute to the set of URLs web fetch may fetch.
6817 Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.
68806818
6881 Each key is a tagged variant: `user_input` is `all` or `none`; the
6882 two tool filters are `all`, `none`, `only` (only the named tools'
6883 results) or `except` (every result but the named tools'). A named tool
6884 must be declared in this request's `tools[]`.
6885
68866819 - `use_cache: optional boolean`
68876820
68886821 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.
from line 6860
69276860
69286861 Maximum number of times the tool can be used in the API request.
69296862
6930 exclusiveMinimum: 0
6863 minimum: 1
69316864
69326865 - `response_inclusion: optional "full" or "excluded"`
69336866
from line 6922
69896922
69906923 Maximum number of tokens used by including web page text content in the context. The limit is approximate and does not apply to binary content such as PDFs.
69916924
6992 exclusiveMinimum: 0
6925 minimum: 1
69936926
69946927 - `max_uses: optional number or null`
69956928
69966929 Maximum number of times the tool can be used in the API request.
69976930
6998 exclusiveMinimum: 0
6931 minimum: 1
69996932
70006933 - `response_inclusion: optional "full" or "excluded"`
70016934
from line 6944
70116944
70126945 - `url_sources: optional BetaWebFetchURLSources or null`
70136946
7014 Which sources contribute to the set of URLs web fetch may fetch.
6947 Which sources contribute to the set of URLs the tool may fetch. Omitted means every source.
70156948
7016 Each key is a tagged variant: `user_input` is `all` or `none`; the
7017 two tool filters are `all`, `none`, `only` (only the named tools'
7018 results) or `except` (every result but the named tools'). A named tool
7019 must be declared in this request's `tools[]`.
7020
70216949 - `use_cache: optional boolean`
70226950
70236951 Whether to use cached content. Set to false to bypass the cache and fetch fresh content. Only set to false when the user explicitly requests fresh content or when fetching rapidly-changing sources.
from line 6960
70326960
70336961 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
70346962
6963 - `string`
6964
70356965 - `"claude-fable-5-1" or "claude-opus-5-5" or "claude-mythos-5-1" or 15 more`
70366966
70376967 The model that will complete your prompt.
from line 7004
70747004
70757005 Powerful intelligence for long-running agents and coding
70767006
7077 - `"claude-mythos-preview"`
7078
7079 New class of intelligence, strongest in coding and cybersecurity
7080
70817007 - `"claude-opus-4-6"`
70827008
70837009 Powerful intelligence for long-running agents and coding
from line 7036
71107036
71117037 High-performance model for agents and coding
71127038
7113 - `string`
7039 - `"claude-mythos-preview"`
71147040
7041 **Deprecated**: Will reach end-of-life on June 30, 2026. Please migrate to claude-mythos-5. Visit https://docs.anthropic.com/en/docs/resources/model-deprecations for more information.
7042
7043 New class of intelligence, strongest in coding and cybersecurity
7044
71157045 - `name: "advisor"`
71167046
71177047 Name of the tool.
from line 7080
71507080
71517081 Maximum number of times the tool can be used in the API request.
71527082
7153 exclusiveMinimum: 0
7083 minimum: 1
71547084
71557085 - `strict: optional boolean`
71567086
from line 7116
71867116
71877117 - `defer_loading: optional boolean`
71887118
7189
7119 If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.
7120
7121 - `strict: optional boolean`
7122
7123 When true, guarantees schema validation on tool names and inputs
7124
7125 - `BetaToolSearchToolRegex20251119 object`
7126
7127 - `type: "tool_search_tool_regex_20251119" or "tool_search_tool_regex"`
7128
7129 - `"tool_search_tool_regex_20251119"`
7130
7131 - `"tool_search_tool_regex"`
7132
7133 - `name: "tool_search_tool_regex"`
7134
7135 Name of the tool.
7136
7137 This is how the tool will be called by the model and in `tool_use` blocks.
7138
7139 - `allowed_callers: optional array of "direct" or "code_execution_20250825" or "code_execution_20260120" or "code_execution_20260521"`
7140
7141 - `"direct"`
7142
7143 - `"code_execution_20250825"`
7144
7145 - `"code_execution_20260120"`
7146
7147 - `"code_execution_20260521"`
7148
7149 - `cache_control: optional BetaCacheControlEphemeral or null`
7150
7151 Create a cache control breakpoint at this content block.
7152
7153 - `defer_loading: optional boolean`
7154
7155 If true, tool will not be included in initial system prompt. Only loaded when returned via tool_reference from tool search.
7156
7157 - `strict: optional boolean`
7158
7159 When true, guarantees schema validation on tool names and inputs
7160
7161 - `BetaMCPToolset object`
7162
7163 Configuration for a group of tools from an MCP server.
7164
7165 Allows configuring enabled status and defer_loading for all tools
7166 from an MCP server, with optional per-tool overrides.
7167
7168 - `type: "mcp_toolset"`
7169
7170 - `mcp_server_name: string`
7171
7172 Name of the MCP server to configure tools for
7173
7174 minLength: 1, maxLength: 255
7175
7176 - `cache_control: optional BetaCacheControlEphemeral or null`
7177
7178 Create a cache control breakpoint at this content block.
7179
7180 - `configs: optional map[BetaMCPToolConfig] or null`
7181
7182 Configuration overrides for specific tools, keyed by tool name
7183
7184 - `defer_loading: optional boolean`
7185
7186 - `enabled: optional boolean`
7187
7188 - `default_config: optional BetaMCPToolDefaultConfig`
7189
7190 Default configuration applied to all tools from this server
7191
7192 - `defer_loading: optional boolean`
7193
7194 - `enabled: optional boolean`
7195
7196 - `tools: optional array of BetaMCPToolParam or null`
7197
7198 The server's tool listing, pinned: when present, the server is not asked for its tools before sampling and exactly these entries, with `default_config` and `configs` applied, are the toolset's tools. Copy it from the `mcp_tool_listing` block of an earlier response.
7199
7200 - `input_schema: map[unknown]`
7201
7202 The tool's input schema as the MCP server lists it, verbatim.
7203
7204 - `name: st
No line in this hunk matches that.