v2026.09.03 (v1.18.27)

What's New

• Anthropic thinking block binding: requests to Claude 5.1 and newer now ask the API to drop
  thinking blocks whose conversation prefix no longer matches, instead of failing the whole request.
  opencode re-renders parts of that prefix between turns (system prompt, tool list, compaction), so
  without this a long session could start rejecting requests outright. Mythos 5.1 is excluded because
  it does not run the check. Blocks the API drops are reported in a warning log.
  • Opt out per model, agent or variant with thinking.blockBinding: false
    (reasoningConfig.blockBinding: false on Bedrock).
• Five-minute defaults for both stream timeouts: headerTimeout now defaults to 300000 ms
  alongside chunkTimeout, so a gateway that accepts a connection and then never sends headers no
  longer hangs the session. Either can still be disabled with false, and anything you set in
  opencode.json takes precedence over a provider preset.

Fixes

• Upstream rebase to v1.18.27 (from v1.18.25):
  • SSE reader cancellation no longer produces an unhandled rejection when the stream errors at the
    same moment the timeout fires.
  • Azure model discovery removed upstream; it no longer writes to stdout.
  • apply_patch omits an empty move path.
  • Tool-call logging no longer resets time.start incorrectly.
  • Bedrock SDK accepts a none reasoning effort.
• Generated v2 SDK types now include dropReasoningEffortWithTools, which the config schema has
  accepted for a while but the published types never exposed.

Install

Try without installing:

npx opencode-ai-nofc

Install globally:

npm install -g opencode-ai-nofc
opencode

Or download binaries below.

Based on upstream opencode v1.18.27.