Platform

OpenClaw / Pi Agent

context-mode version

1.0.53

Full doctor output (REQUIRED)

## context-mode doctor

- [x] Runtimes: 8/11 (73%) — javascript, shell, typescript, python, ruby, go, php, perl
- [x] Performance: FAST (Bun)
- [x] Server test: PASS
- [x] FTS5 / SQLite: PASS — native module works
- [x] Hook script: PASS — hooks/pretooluse.mjs
- [x] Version: v1.0.53

Exact prompt that triggered the bug (REQUIRED)

No specific prompt triggers it — it occurs when the conversation is long enough to trigger compaction. The compaction hook fires, OpenClaw truncates conversation history, and the next API call to Anthropic fails because `thinking` / `redacted_thinking` blocks in the truncated history were modified.

Typical trigger: a session with 15+ tool calls using Anthropic `claude-opus-4-6` with extended thinking enabled. After compaction, the next user message triggers the error.

Full error output (REQUIRED)

LLM request rejected: messages.13.content.10: thinking or redacted_thinking blocks in the latest assistant message cannot be modified. These blocks must remain as they were in the original response.

Steps to reproduce (REQUIRED)

1. Install context-mode v1.0.53 as OpenClaw native plugin (npm run install:openclaw)
2. Configure OpenClaw with an Anthropic model that has extended thinking enabled (e.g. claude-opus-4-6 with thinkingDefault: "xhigh")
3. Start a conversation and make many tool calls (15+) to grow the context window
4. Wait for compaction to trigger (context-mode's before_compaction hook fires)
5. Send another message after compaction
6. Anthropic API rejects the request with the thinking block validation error above

What have you tried to fix it?

• Verified OpenClaw is on v2026.3.24 which includes the fix for a similar issue in a different code path (#52961: "preserve latest assistant thinking and redacted-thinking block ordering during transcript image sanitization")
• Searched context-mode source code: git log --all --oneline --grep='thinking' returns 0 results, rg 'thinking|redacted_thinking' src/ build/ returns 0 matches — there is zero handling of thinking blocks anywhere in the codebase
• The compaction logic (compact() returning firstKeptEntryId) has no awareness of Anthropic's thinking block constraints
• Using /new to reset the session before compaction triggers is a workaround but not a fix

Pre-submission checklist

• I am on the LATEST version (ran ctx-upgrade)
• I searched existing issues and this is not a duplicate
• I tried to debug this myself (read source, ran hooks manually, etc.)
• I understand that PRs are preferred and issues don't guarantee a fix

Operating System

Linux (Ubuntu/Debian)

JS Runtime

node v22.21.0, bun 1.3.10