Create Session changedapi/beta/sessions/create
Nearest release: v2.1.281, published an hour before 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+16added
Lines−4removed
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17
where the diff opens
First seen
14 Aug 2026
this site's first read of the page
Recorded edits11to 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 43 more`
20 - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 45 more`
2121
2222 - `"message-batches-2024-09-24"`
2323
from line 111
111111
112112 - `"compact-2026-09-04"`
113113
114 - `"inline-tools-2026-09-15"`
115
116 - `"mcp-client-2026-09-15"`
117
114118- `"anthropic-workspace-id": optional string`
115119
116120 Optional header to select the Workspace for this request. The value is a Workspace ID (for example, `wrkspc_011CZkZaBF1tNoB5wlCeusgy`).
from line 181
177181
178182 Replacement model. Accepts the model string, e.g. `claude-opus-5`, or a `model_config` object. Omit to use the agent's model.
179183
180 - `BetaManagedAgentsModel = "claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more or string`
184 - `BetaManagedAgentsModel = "claude-opus-5-5" or "claude-fable-5-1" or "claude-sonnet-5" or 12 more or string`
181185
182186 The model that will power your agent.
183187
184188 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
185189
186 - `"claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more`
190 - `"claude-opus-5-5" or "claude-fable-5-1" or "claude-sonnet-5" or 12 more`
187191
188192 The model that will power your agent.
189193
190194 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
191195
196 - `"claude-opus-5-5"`
197
198 Powerful intelligence for coding, knowledge work, and long-running agents
199
192200 - `"claude-fable-5-1"`
193201
194202 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
from line 1189
11811189
11821190 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
11831191
1184 - `"claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more`
1192 - `"claude-opus-5-5" or "claude-fable-5-1" or "claude-sonnet-5" or 12 more`
11851193
11861194 The model that will power your agent.
11871195
11881196 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
1197
1198 - `"claude-opus-5-5"`
1199
1200 Powerful intelligence for coding, knowledge work, and long-running agents
11891201
11901202 - `"claude-fable-5-1"`
11911203
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