fix(agents): preserve thinking blocks in latest assistant message during compaction by Nipurn123 · Pull Request #25381 · openclaw/openclaw

Nipurn123 · 2026-02-24T12:28:03Z

Summary

Fixes [Bug]: thinking/redacted_thinking blocks get modified during context compaction → API 400 error #25347 where thinking/redacted_thinking blocks were being modified during context compaction, causing API 400 errors
Modified dropThinkingBlocks() to preserve thinking blocks in the latest assistant message (Anthropic API requirement)
Continues to strip thinking blocks from older assistant messages (needed for GitHub Copilot compatibility)

Root Cause

The Anthropic API requires that thinking/redacted_thinking blocks in the latest assistant message remain exactly as received. The dropThinkingBlocks() function was stripping ALL thinking blocks from ALL assistant messages, causing this error during longer conversations:

LLM request rejected: messages.51.content.1: thinking or redacted_thinking blocks in the latest assistant message cannot be modified.

Changes

src/agents/pi-embedded-runner/thinking.ts - Added logic to find and skip the latest assistant message when dropping thinking blocks
src/agents/pi-embedded-runner/thinking.test.ts - Added 4 new tests for latest assistant preservation
src/agents/pi-embedded-runner.sanitize-session-history.test.ts - Updated 3 tests + added 1 new test for the behavior

Testing

All 31 related tests pass
pnpm check passes (lint/format)

Greptile Summary

This PR bundles three independent changes: (1) a fix for Anthropic API 400 errors by preserving thinking blocks in the latest assistant message during context compaction, (2) a refactor of extra-params.ts from inline provider if/else to a registry-based pattern, and (3) a new Telegram sendDice action with full threading/gating support plus orphan transcript cleanup on gateway startup.

Thinking block fix (thinking.ts): dropThinkingBlocks() now scans backward to find the latest assistant message and preserves it intact, only stripping thinking blocks from older assistant messages. This directly fixes the API rejection error. Well-tested with 4 new unit tests and updated integration tests.
Provider handler registry (extra-params.ts): Refactored provider-specific stream wrapper logic into a Map<string, ProviderHandler[]> registry with a * wildcard for universal handlers. Functionally equivalent to the old code — Map insertion order preserves the original application sequence.
Telegram dice action: Adds sendDice support across the full stack — types, send function, action handler, plugin adapter, and action spec. Includes emoji validation, threading, and gating. Minor formatting bug in the error message (missing space between emojis).
Orphan transcript cleanup (server-startup.ts): New cleanupOrphanTranscripts() archives .jsonl transcript files not referenced in the session store, with a safety threshold of 10 files before cleanup activates.

Confidence Score: 4/5

This PR is safe to merge with one minor formatting fix recommended in the dice emoji error message.
The core thinking block fix is well-implemented and thoroughly tested. The provider handler registry refactor is functionally equivalent to the original code. The Telegram dice feature follows established patterns. The only issue found is a missing space in an error message string. The orphan cleanup has appropriate safety guards (threshold, best-effort error handling).
src/agents/tools/telegram-actions.ts has a minor formatting bug in the dice emoji error message (missing space between ⚽ and 🎳).

_{Last reviewed commit: 70f78dd}

- Add sendDiceTelegram function to telegram/send.ts - Support all dice emojis: 🎲 🎯 🏀 ⚽ 🎳 🎰 - Return dice value in result so agent knows outcome - Wire into message tool via handleTelegramAction - Default enabled via sendDice action gate Closes openclaw#25263

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

Replace hardcoded provider checks with a provider handler registry pattern: - Add ProviderHandler type with createWrapper and enabledWhen hooks - Create providerHandlers registry with entries for: - anthropic: beta headers - openrouter: app headers + reasoning effort + system cache - amazon-bedrock: non-Anthropic cache disable - zai/z-ai: tool_stream injection - *: OpenAI Responses store wrapper (applies to all) - Simplify applyExtraParamsToAgent with registry iteration Benefits: - Easier to add new providers - Clearer separation of concerns - Each provider's logic is self-contained Closes openclaw#25311

)

…ing compaction Anthropic's API requires that thinking/redacted_thinking blocks in the latest assistant message remain exactly as received. The dropThinkingBlocks() function was stripping ALL thinking blocks from ALL assistant messages, causing API 400 errors during context compaction in longer conversations. Now the function preserves thinking blocks in the latest assistant message while still stripping them from older messages (needed for GitHub Copilot compatibility). Fixes openclaw#25347

greptile-apps

_{12 files reviewed, 1 comment}

_{Edit Code Review Agent Settings | Greptile}

greptile-apps · 2026-02-24T12:32:54Z

src/agents/tools/telegram-actions.ts

+    const to = readStringParam(params, "to", { required: true });
+    const emoji = readStringParam(params, "emoji");
+    if (emoji && !["🎲", "🎯", "🏀", "⚽", "🎳", "🎰"].includes(emoji)) {
+      throw new Error(`Invalid dice emoji: ${emoji}. Must be one of: 🎲 🎯 🏀 ⚽🎳 🎰`);


Missing space in error message

The error message is missing a space between ⚽ and 🎳. The validation array on line 382 correctly lists all 6 emoji as separate items, but the user-facing error message concatenates two of them.

Suggested change

throw new Error(`Invalid dice emoji: ${emoji}. Must be one of: 🎲 🎯 🏀 ⚽🎳 🎰`);

throw new Error(`Invalid dice emoji: ${emoji}. Must be one of: 🎲 🎯 🏀 ⚽ 🎳 🎰`);

Prompt To Fix With AI

This is a comment left during a code review. Path: src/agents/tools/telegram-actions.ts Line: 383 Comment: **Missing space in error message** The error message is missing a space between `⚽` and `🎳`. The validation array on line 382 correctly lists all 6 emoji as separate items, but the user-facing error message concatenates two of them. ```suggestion throw new Error(`Invalid dice emoji: ${emoji}. Must be one of: 🎲 🎯 🏀 ⚽ 🎳 🎰`); ``` How can I resolve this? If you propose a fix, please make it concise.

…ompaction-25347 # Conflicts: # src/agents/pi-embedded-runner/extra-params.ts

openclaw-barnacle · 2026-03-03T05:34:01Z

This pull request has been automatically marked as stale due to inactivity.
Please add updates or it will be closed.

xiaoyaner0201

🔍 Duplicate PR Group: Anthropic Thinking Block Compaction

This PR is one of 7 open PRs addressing the same issue: Anthropic thinking/redacted_thinking blocks from older assistant messages cause API errors during context compaction.

Related PRs

PR	Author	Date	Approach	Preserves latest	redacted_thinking	Compaction path	Tests	Clean diff
#24261	@Vaibhavee89	02-23	Guard functions + logging	N/A (no actual strip)	Detect only	❌	Medium	✅
#25381	@Nipurn123	02-24	Modify `dropThinkingBlocks` skip latest	✅	❌	❌	Good	❌ (bundles sendDice)
#27142	@slatem	02-26	Extend `dropThinkingBlocks` to Anthropic	❌ (strips all)	✅	❌	Limited	✅
#39919	@taw0002	03-08	New strip function in sanitizeSessionHistory	✅	✅	❌	Good	✅
#39940	@liangruochong44-ui	03-08	Policy flag for Anthropic	❌ (strips all)	✅	❌	Medium	❌ (bundles cron/SQLite/UI)
#43783	@coletoncodes	03-12	New `stripThinkingFromNonLatestAssistant` + compact path	✅	✅	✅	Best	✅
#44650	@rikisann	03-13	Runtime monkey-patch of node_modules	✅	✅	❌	None	⚠️ Fragile approach

Analysis

After reading all 7 diffs:

#43783 is the strongest candidate. It:

Creates a standalone stripThinkingFromNonLatestAssistant() without changing dropThinkingBlocks semantics (preserves Copilot behavior)
Integrates via existing policy.preserveSignatures flag (proper transcript policy mechanism)
Only PR that also fixes the compaction path (compact.ts) — others only fix sanitizeSessionHistory
Handles both thinking and redacted_thinking block types
Clean diff with comprehensive tests (toolResult interleaving, empty blocks, reference equality)

#39919 is a close second (same core function, clean diff, good tests) but misses the compaction path.

Notable discovery from #44650: sanitizeSurrogates may corrupt thinking block signatures — worth investigating separately even though the monkey-patch approach is not viable.

Not recommended: #27142 and #39940 strip thinking from ALL messages including latest (breaks multi-turn quality). #25381 and #39940 bundle unrelated changes.

Similarities identified via embedding-based clustering (cosine > 0.82). Maintainers: #43783 appears ready for review.

openclaw-barnacle · 2026-03-30T04:27:52Z

This pull request has been automatically marked as stale due to inactivity.
Please add updates or it will be closed.

obviyus · 2026-04-01T11:05:54Z

Closing as duplicate; this was superseded by #58916.

Nipurn123 and others added 8 commits February 24, 2026 16:37

Update src/telegram/send.ts

44ca639

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

Update src/agents/tools/telegram-actions.ts

1b6697c

Co-authored-by: greptile-apps[bot] <165735046+greptile-apps[bot]@users.noreply.github.com>

fix: use validEmoji for type-safe dice emoji param

1b56a82

ci: trigger CI rerun

3c4e37e

gateway: add orphan transcript cleanup on startup (closes openclaw#25373

191ab17

)

openclaw-barnacle bot added channel: telegram Channel integration: telegram gateway Gateway runtime agents Agent runtime and tooling size: L labels Feb 24, 2026

greptile-apps bot reviewed Feb 24, 2026

View reviewed changes

Merge remote-tracking branch 'origin/main' into fix/thinking-blocks-c…

761a355

…ompaction-25347 # Conflicts: # src/agents/pi-embedded-runner/extra-params.ts

openclaw-barnacle bot added the stale Marked as stale due to inactivity label Mar 3, 2026

xiaoyaner0201 reviewed Mar 13, 2026

View reviewed changes

openclaw-barnacle bot removed the stale Marked as stale due to inactivity label Mar 23, 2026

openclaw-barnacle bot added the stale Marked as stale due to inactivity label Mar 30, 2026

obviyus mentioned this pull request Apr 1, 2026

fix: preserve anthropic thinking blocks on replay #58916

Merged

obviyus closed this Apr 1, 2026

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fix(agents): preserve thinking blocks in latest assistant message during compaction#25381

fix(agents): preserve thinking blocks in latest assistant message during compaction#25381
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Nipurn123:fix/thinking-blocks-compaction-25347

Nipurn123 commented Feb 24, 2026 •

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	throw new Error(`Invalid dice emoji: ${emoji}. Must be one of: 🎲 🎯 🏀 ⚽🎳 🎰`);
	throw new Error(`Invalid dice emoji: ${emoji}. Must be one of: 🎲 🎯 🏀 ⚽ 🎳 🎰`);

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Summary

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Greptile Summary

Confidence Score: 4/5

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🔍 Duplicate PR Group: Anthropic Thinking Block Compaction

Related PRs

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Nipurn123 commented Feb 24, 2026 •

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