Create Session changedapi/beta/sessions/create
Nearest release: v2.1.286, published an hour 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
Lines+248added
Lines−266removed
From line
17
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits15to this page, all time
The whole hunk
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1717
1818 - `string`
1919
20 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 45 more`
20 - `"message-batches-2024-09-24"`
2121
22 - `"message-batches-2024-09-24"`
22 - `"prompt-caching-2024-07-31"`
2323
24 - `"prompt-caching-2024-07-31"`
24 - `"computer-use-2024-10-22"`
2525
26 - `"computer-use-2024-10-22"`
26 - `"computer-use-2025-01-24"`
2727
28 - `"computer-use-2025-01-24"`
28 - `"pdfs-2024-09-25"`
2929
30 - `"pdfs-2024-09-25"`
30 - `"token-counting-2024-11-01"`
3131
32 - `"token-counting-2024-11-01"`
32 - `"token-efficient-tools-2025-02-19"`
3333
34 - `"token-efficient-tools-2025-02-19"`
34 - `"output-128k-2025-02-19"`
3535
36 - `"output-128k-2025-02-19"`
36 - `"files-api-2025-04-14"`
3737
38 - `"files-api-2025-04-14"`
38 - `"mcp-client-2025-04-04"`
3939
40 - `"mcp-client-2025-04-04"`
40 - `"mcp-client-2025-11-20"`
4141
42 - `"mcp-client-2025-11-20"`
42 - `"dev-full-thinking-2025-05-14"`
4343
44 - `"dev-full-thinking-2025-05-14"`
44 - `"interleaved-thinking-2025-05-14"`
4545
46 - `"interleaved-thinking-2025-05-14"`
46 - `"code-execution-2025-05-22"`
4747
48 - `"code-execution-2025-05-22"`
48 - `"extended-cache-ttl-2025-04-11"`
4949
50 - `"extended-cache-ttl-2025-04-11"`
50 - `"context-1m-2025-08-07"`
5151
52 - `"context-1m-2025-08-07"`
52 - `"context-management-2025-06-27"`
5353
54 - `"context-management-2025-06-27"`
54 - `"model-context-window-exceeded-2025-08-26"`
5555
56 - `"model-context-window-exceeded-2025-08-26"`
56 - `"skills-2025-10-02"`
5757
58 - `"skills-2025-10-02"`
58 - `"fast-mode-2026-02-01"`
5959
60 - `"fast-mode-2026-02-01"`
60 - `"output-300k-2026-03-24"`
6161
62 - `"output-300k-2026-03-24"`
62 - `"user-profiles-2026-03-24"`
6363
64 - `"user-profiles-2026-03-24"`
64 - `"user-profiles-2026-08-18"`
6565
66 - `"user-profiles-2026-08-18"`
66 - `"user-profiles-2026-09-04"`
6767
68 - `"user-profiles-2026-09-04"`
68 - `"advisor-tool-2026-03-01"`
6969
70 - `"advisor-tool-2026-03-01"`
70 - `"managed-agents-2026-04-01"`
7171
72 - `"managed-agents-2026-04-01"`
72 - `"cache-diagnosis-2026-04-07"`
7373
74 - `"cache-diagnosis-2026-04-07"`
74 - `"dreaming-2026-04-21"`
7575
76 - `"dreaming-2026-04-21"`
76 - `"thinking-token-count-2026-05-13"`
7777
78 - `"thinking-token-count-2026-05-13"`
78 - `"server-side-fallback-2026-06-01"`
7979
80 - `"server-side-fallback-2026-06-01"`
80 - `"server-side-fallback-2026-07-01"`
8181
82 - `"server-side-fallback-2026-07-01"`
82 - `"fallback-credit-2026-06-01"`
8383
84 - `"fallback-credit-2026-06-01"`
84 - `"fallback-credit-2026-07-01"`
8585
86 - `"fallback-credit-2026-07-01"`
86 - `"agent-memory-2026-07-22"`
8787
88 - `"agent-memory-2026-07-22"`
88 - `"mid-conversation-tool-changes-2026-07-01"`
8989
90 - `"mid-conversation-tool-changes-2026-07-01"`
90 - `"compact-2026-01-12"`
9191
92 - `"compact-2026-01-12"`
92 - `"computer-use-2025-11-24"`
9393
94 - `"computer-use-2025-11-24"`
94 - `"mcp-tunnels-2026-06-22"`
9595
96 - `"mcp-tunnels-2026-06-22"`
96 - `"structured-outputs-2025-11-13"`
9797
98 - `"structured-outputs-2025-11-13"`
98 - `"task-budgets-2026-03-13"`
9999
100 - `"task-budgets-2026-03-13"`
100 - `"thinking-display-updates-2026-08-18"`
101101
102 - `"thinking-display-updates-2026-08-18"`
102 - `"ce-user-management-2026-07-13"`
103103
104 - `"ce-user-management-2026-07-13"`
104 - `"mid-conversation-output-config-2026-07-01"`
105105
106 - `"mid-conversation-output-config-2026-07-01"`
106 - `"thinking-binding-controls-2026-08-01"`
107107
108 - `"thinking-binding-controls-2026-08-01"`
108 - `"mid-conversation-system-clear-at-2026-08-21"`
109109
110 - `"mid-conversation-system-clear-at-2026-08-21"`
110 - `"compact-2026-09-04"`
111111
112 - `"compact-2026-09-04"`
112 - `"inline-tools-2026-09-15"`
113113
114 - `"inline-tools-2026-09-15"`
114 - `"mcp-client-2026-09-15"`
115115
116 - `"mcp-client-2026-09-15"`
117
118116- `"anthropic-workspace-id": optional string`
119117
120118 Optional header to select the Workspace for this request. The value is a Workspace ID (for example, `wrkspc_011CZkZaBF1tNoB5wlCeusgy`).
from line 185
187185
188186 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
189187
190 - `"claude-sonnet-5-5" or "claude-opus-5-5" or "claude-fable-5-1" or 13 more`
188 - `"claude-sonnet-5-5"`
191189
192 The model that will power your agent.
190 Efficient model for coding and agents
193191
194 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
192 - `"claude-opus-5-5"`
195193
196 - `"claude-sonnet-5-5"`
194 Powerful intelligence for coding, knowledge work, and long-running agents
197195
198 Efficient model for coding and agents
196 - `"claude-fable-5-1"`
199197
200 - `"claude-opus-5-5"`
198 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
201199
202 Powerful intelligence for coding, knowledge work, and long-running agents
200 - `"claude-sonnet-5"`
203201
204 - `"claude-fable-5-1"`
202 Efficient model for coding and agents
205203
206 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
204 - `"claude-fable-5"`
207205
208 - `"claude-sonnet-5"`
206 Next generation of intelligence for the hardest knowledge work and coding problems
209207
210 Efficient model for coding and agents
208 - `"claude-opus-5"`
211209
212 - `"claude-fable-5"`
210 Powerful intelligence for long-running agents and coding
213211
214 Next generation of intelligence for the hardest knowledge work and coding problems
212 - `"claude-opus-4-8"`
215213
216 - `"claude-opus-5"`
214 Powerful intelligence for long-running agents and coding
217215
218 Powerful intelligence for long-running agents and coding
216 - `"claude-opus-4-7"`
219217
220 - `"claude-opus-4-8"`
218 Powerful intelligence for long-running agents and coding
221219
222 Powerful intelligence for long-running agents and coding
220 - `"claude-opus-4-6"`
223221
224 - `"claude-opus-4-7"`
222 Powerful intelligence for long-running agents and coding
225223
226 Powerful intelligence for long-running agents and coding
224 - `"claude-sonnet-4-6"`
227225
228 - `"claude-opus-4-6"`
226 Best combination of speed and intelligence
229227
230 Powerful intelligence for long-running agents and coding
228 - `"claude-haiku-4-5"`
231229
232 - `"claude-sonnet-4-6"`
230 Fastest model with near-frontier intelligence
233231
234 Best combination of speed and intelligence
232 - `"claude-haiku-4-5-20251001"`
235233
236 - `"claude-haiku-4-5"`
234 Fastest model with near-frontier intelligence
237235
238 Fastest model with near-frontier intelligence
236 - `"claude-opus-4-5"`
239237
240 - `"claude-haiku-4-5-20251001"`
238 Powerful intelligence for long-running agents and coding
241239
242 Fastest model with near-frontier intelligence
240 - `"claude-opus-4-5-20251101"`
243241
244 - `"claude-opus-4-5"`
242 Powerful intelligence for long-running agents and coding
245243
246 Powerful intelligence for long-running agents and coding
244 - `"claude-sonnet-4-5"`
247245
248 - `"claude-opus-4-5-20251101"`
246 High-performance model for agents and coding
249247
250 Powerful intelligence for long-running agents and coding
248 - `"claude-sonnet-4-5-20250929"`
251249
252 - `"claude-sonnet-4-5"`
250 High-performance model for agents and coding
253251
254 High-performance model for agents and coding
255
256 - `"claude-sonnet-4-5-20250929"`
257
258 High-performance model for agents and coding
259
260252 - `string`
261253
262254 - `BetaManagedAgentsModelConfigParams object`
from line 265
273265
274266 How hard Claude works on each inference call. Accepts a bare level string (`"high"`) or `{"type": "high"}`. On create, omitting it resolves the per-model default; on update, omitting it leaves the stored value unchanged.
275267
276 - `BetaManagedAgentsEffortLevel = "low" or "medium" or "high" or 2 more`
268 - `"low"`
277269
278 How hard Claude works on each turn. Higher levels favor reasoning depth over latency. Not all models accept every level; invalid combinations are rejected at create time.
270 Low effort. Favors latency over reasoning depth.
279271
280 - `"low"`
272 - `"medium"`
281273
282 Low effort. Favors latency over reasoning depth.
274 Medium effort. Balances latency and reasoning depth.
283275
284 - `"medium"`
276 - `"high"`
285277
286 Medium effort. Balances latency and reasoning depth.
278 High effort. Favors reasoning depth.
287279
288 - `"high"`
280 - `"xhigh"`
289281
290 High effort. Favors reasoning depth.
282 Extra-high effort. Not all models accept this level.
291283
292 - `"xhigh"`
284 - `"max"`
293285
294 Extra-high effort. Not all models accept this level.
286 Maximum effort. Favors reasoning depth over latency.
295287
296 - `"max"`
297
298 Maximum effort. Favors reasoning depth over latency.
299
300288 - `BetaManagedAgentsEffortLow object`
301289
302290 Low effort. Favors latency over reasoning depth.
from line 1181
11931181
11941182 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
11951183
1196 - `"claude-sonnet-5-5" or "claude-opus-5-5" or "claude-fable-5-1" or 13 more`
1184 - `"claude-sonnet-5-5"`
11971185
1198 The model that will power your agent.
1186 Efficient model for coding and agents
11991187
1200 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1188 - `"claude-opus-5-5"`
12011189
1202 - `"claude-sonnet-5-5"`
1190 Powerful intelligence for coding, knowledge work, and long-running agents
12031191
1204 Efficient model for coding and agents
1192 - `"claude-fable-5-1"`
12051193
1206 - `"claude-opus-5-5"`
1194 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
12071195
1208 Powerful intelligence for coding, knowledge work, and long-running agents
1196 - `"claude-sonnet-5"`
12091197
1210 - `"claude-fable-5-1"`
1198 Efficient model for coding and agents
12111199
1212 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
1200 - `"claude-fable-5"`
12131201
1214 - `"claude-sonnet-5"`
1202 Next generation of intelligence for the hardest knowledge work and coding problems
12151203
1216 Efficient model for coding and agents
1204 - `"claude-opus-5"`
12171205
1218 - `"claude-fable-5"`
1206 Powerful intelligence for long-running agents and coding
12191207
1220 Next generation of intelligence for the hardest knowledge work and coding problems
1208 - `"claude-opus-4-8"`
12211209
1222 - `"claude-opus-5"`
1210 Powerful intelligence for long-running agents and coding
12231211
1224 Powerful intelligence for long-running agents and coding
1212 - `"claude-opus-4-7"`
12251213
1226 - `"claude-opus-4-8"`
1214 Powerful intelligence for long-running agents and coding
12271215
1228 Powerful intelligence for long-running agents and coding
1216 - `"claude-opus-4-6"`
12291217
1230 - `"claude-opus-4-7"`
1218 Powerful intelligence for long-running agents and coding
12311219
1232 Powerful intelligence for long-running agents and coding
1220 - `"claude-sonnet-4-6"`
12331221
1234 - `"claude-opus-4-6"`
1222 Best combination of speed and intelligence
12351223
1236 Powerful intelligence for long-running agents and coding
1224 - `"claude-haiku-4-5"`
12371225
1238 - `"claude-sonnet-4-6"`
1226 Fastest model with near-frontier intelligence
12391227
1240 Best combination of speed and intelligence
1228 - `"claude-haiku-4-5-20251001"`
12411229
1242 - `"claude-haiku-4-5"`
1230 Fastest model with near-frontier intelligence
12431231
1244 Fastest model with near-frontier intelligence
1232 - `"claude-opus-4-5"`
12451233
1246 - `"claude-haiku-4-5-20251001"`
1234 Powerful intelligence for long-running agents and coding
12471235
1248 Fastest model with near-frontier intelligence
1236 - `"claude-opus-4-5-20251101"`
12491237
1250 - `"claude-opus-4-5"`
1238 Powerful intelligence for long-running agents and coding
12511239
1252 Powerful intelligence for long-running agents and coding
1240 - `"claude-sonnet-4-5"`
12531241
1254 - `"claude-opus-4-5-20251101"`
1242 High-performance model for agents and coding
12551243
1256 Powerful intelligence for long-running agents and coding
1244 - `"claude-sonnet-4-5-20250929"`
12571245
1258 - `"claude-sonnet-4-5"`
1259
1260 High-performance model for agents and coding
1261
1262 - `"claude-sonnet-4-5-20250929"`
1263
1264 High-performance model for agents and coding
1246 High-performance model for agents and coding
12651247
12661248 - `string`
12671249
No line in this hunk matches that.