Sweep 22 Sep 2026 · 17:19Z Build v2.1.280 501 read Stable v2.1.267 Latest v2.1.280 Next v2.1.280 Feeds RSS JSON llms.txt Unofficial
One change · api

Update Session changed

api/beta/sessions/update

Nearest release: v2.1.258, 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+15added
Lines−5removed
From line 16 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits9to this page, all time

The whole hunk

from line 16, old and new numbered
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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## Body parameters
104110 
105111- `agent: optional BetaManagedAgentsSessionAgentUpdate`
from line 580
574580 
575581 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
576582 
577 - `"claude-sonnet-5" or "claude-fable-5" or "claude-opus-5" or 10 more`
583 - `"claude-fable-5-1" or "claude-sonnet-5" or "claude-fable-5" or 11 more`
578584 
579585 The model that will power your agent.
580586 
581587 See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.
582588 
589 - `"claude-fable-5-1"`
590 
591 Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows
592 
583593 - `"claude-sonnet-5"`
584594 
585595 High-performance model for coding and agents
from line 1138
11281138 
11291139 - `outcome_evaluations: array of BetaManagedAgentsOutcomeEvaluationResource`
11301140 
1131 Per-outcome evaluation state. One entry per define_outcome event sent to the session.
1141 Per-outcome evaluation state. One entry per `define_outcome` event sent to the session.
11321142 
11331143 - `completed_at: string or null`
11341144 
from line 1152
11421152 
11431153 - `explanation: string or null`
11441154 
1145 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.
1155 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.
11461156 
11471157 - `iteration: number`
11481158 
from line 1280
12701280 
12711281 - `active_seconds: optional number`
12721282 
1273 Cumulative time in seconds the session spent in running status. Excludes idle time.
1283 Cumulative time in seconds the session spent in `running` status. Excludes idle time.
12741284 
12751285 format: double
12761286