Create Session changedapi/beta/sessions/create
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Lines+21added
Lines−7removed
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12
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14 Aug 2026
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Recorded edits26to this page, all time
The whole hunk
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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"`
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9797 - `"ce-user-management-2026-07-13"`
9898
99 - `"mid-conversation-output-config-2026-07-01"`
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101 - `"thinking-binding-controls-2026-08-01"`
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103 - `"mid-conversation-system-clear-at-2026-08-21"`
104
99105## Body parameters
100106
101107- `agent: string or BetaManagedAgentsAgentParams or BetaManagedAgentsAgentWithOverridesParams`
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156162
157163 Replacement model. Accepts the model string, e.g. `claude-opus-5`, or a `model_config` object. Omit to use the agent's model.
158164
159 - `BetaManagedAgentsModel = "claude-sonnet-5" or "claude-fable-5" or "claude-opus-5" or 10 more or string`
165 - `BetaManagedAgentsModel = "claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more or string`
160166
161167 The model that will power your agent.
162168
163169 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
164170
165 - `"claude-sonnet-5" or "claude-fable-5" or "claude-opus-5" or 10 more`
171 - `"claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more`
166172
167173 The model that will power your agent.
168174
169175 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
170176
177 - `"claude-fable-5-1"`
178
179 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
180
171181 - `"claude-sonnet-5"`
172182
173183 High-performance model for coding and agents
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10961106
10971107 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
10981108
1099 - `"claude-sonnet-5" or "claude-fable-5" or "claude-opus-5" or 10 more`
1109 - `"claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more`
11001110
11011111 The model that will power your agent.
11021112
11031113 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
11041114
1115 - `"claude-fable-5-1"`
1116
1117 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
1118
11051119 - `"claude-sonnet-5"`
11061120
11071121 High-performance model for coding and agents
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16501664
16511665 - `outcome_evaluations: array of BetaManagedAgentsOutcomeEvaluationResource`
16521666
1653 Per-outcome evaluation state. One entry per define_outcome event sent to the session.
1667 Per-outcome evaluation state. One entry per `define_outcome` event sent to the session.
16541668
16551669 - `completed_at: string or null`
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16641678
16651679 - `explanation: string or null`
16661680
1667 Grader's verdict text from the most recent evaluation. For satisfied, explains why criteria are met; for needs_revision (intermediate), what's missing; for failed, why unrecoverable.
1681 Grader's verdict text from the most recent evaluation. For `satisfied`, explains why criteria are met; for `needs_revision` (intermediate), what's missing; for `failed`, why unrecoverable.
16681682
16691683 - `iteration: number`
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17921806
17931807 - `active_seconds: optional number`
17941808
1795 Cumulative time in seconds the session spent in running status. Excludes idle time.
1809 Cumulative time in seconds the session spent in `running` status. Excludes idle time.
17961810
17971811 format: double
17981812
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