Follow Discord
Sweep 22 Oct 2026 · 04:32Z Build v2.1.308 527 read Stable v2.1.308 Latest v2.1.308 Next v2.1.309 Feeds RSS JSON llms.txt llms-full.txt Unofficial
Reading a new release v2.1.309 First look · 1/6 0 findings $0.00 so far
One change · api

claude-api-skill changedagents-and-tools/agent-skills/claude-api-skill

Nearest release: v2.1.239, published 2 hours 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+1added
Lines−1removed
From line 120 where the diff opens
First seen 14 Aug 2026 this site's first read of the page
Recorded edits16to this page, all time

The whole hunk

from line 120, old and new numbered
/
lines
from line 120
120120* **Cloud platform detection**, preserving platform-specific model ID formats (for example, the `anthropic.` prefix on Amazon Bedrock) and skipping changes for features that are unavailable on partner-operated platforms
121121* **Breaking parameter changes**, such as removing `temperature`, `top_p`, and `top_k` for Claude Opus 4.8 and Claude Opus 4.7, and converting `thinking: {type: "enabled", budget_tokens: N}` to `thinking: {type: "adaptive"}`
122122* **Prefill replacement**, converting assistant-message prefill patterns to [structured outputs](https://platform.claude.com/docs/en/build-with-claude/structured-outputs) where applicable
123* **Beta header cleanup**, removing headers that are GA on the target model (for example, `effort-2025-11-24`, `fine-grained-tool-streaming-2025-05-14`, `interleaved-thinking-2025-05-14`) and switching back from `client.beta.messages.create` to `client.messages.create`
123* **Beta header cleanup**, removing beta headers that the target model doesn't require (for example, `effort-2025-11-24`, `fine-grained-tool-streaming-2025-05-14`, `interleaved-thinking-2025-05-14`) and switching back from `client.beta.messages.create` to `client.messages.create`
124124* **Effort calibration**, recommending an `output_config.effort` starting point for the target model (for example, the default `high` on Claude Opus 5, and `xhigh` for coding and agentic use cases on Claude Opus 4.8 and Claude Opus 4.7)
125125* **Prompt-behavior tuning**, flagging length-control, tool-triggering, subagent, and instruction-following prompts that may behave differently on the target model
126126* **Silent default handling**, opting back into thinking summarization (`thinking.display: "summarized"`) when reasoning is surfaced to users on Claude Opus 4.8 and Claude Opus 4.7
Feedback