fix: detect additional context overflow error patterns to prevent leak to user by echoVic · Pull Request #20539 · openclaw/openclaw

echoVic · 2026-02-19T02:23:06Z

Problem

The context overflow error format used by some providers:

LLM request rejected: input length and max_tokens exceed context limit: 170636 + 34048 > 200000, decrease input length or max_tokens and try again

was not caught by isContextOverflowError(). It fell through to formatAssistantErrorText()'s invalidRequest regex fallback, which returned the raw error verbatim as LLM request rejected: ... — leaking internal token counts and context limits to the user.

Solution

Add three new patterns to isContextOverflowError():

"exceed context limit" — direct substring match
"exceeds the model's maximum context" — alternate provider wording
max_tokens / input length + exceed + context — compound match for variations

These errors are now rewritten to the standard friendly message:

Context overflow: prompt too large for the model. Try /reset (or /new) to start a fresh session, or use a larger-context model.

Impact

Since isContextOverflowError() is checked before the invalidRequest regex in formatAssistantErrorText(), these patterns are now caught early and never leak raw details.

Greptile Summary

Added four new error pattern detections to isContextOverflowError() to catch provider error formats that were previously falling through to the generic error handler, which leaked internal token counts and context limits to users. The new patterns detect errors containing "exceed context limit", "exceeds the model's maximum context", and compound patterns matching max_tokens/input length + exceed + context.

Confidence Score: 5/5

This PR is safe to merge with minimal risk
The changes add four new substring checks to an existing error detection function. The logic is straightforward and defensive - the compound patterns require multiple keywords to match, reducing false positive risk. The change prevents information leakage by catching errors earlier in the error handling flow, which is a security improvement. No breaking changes or complex logic introduced.
No files require special attention

_{Last reviewed commit: 3e36a0f}

…k to user Fixes openclaw#9951 The error 'input length and max_tokens exceed context limit: 170636 + 34048 > 200000' was not caught by isContextOverflowError() and leaked to users via formatAssistantErrorText()'s invalidRequest fallback. Add three new patterns to isContextOverflowError(): - 'exceed context limit' (direct match) - 'exceeds the model\'s maximum context' - max_tokens/input length + exceed + context (compound match) These are now rewritten to the friendly context overflow message.

vincentkoc · 2026-02-23T14:41:58Z

Rebase + readiness update:

Rebases cleanly onto current main.
Added regression coverage in pi-embedded-helpers.isbillingerrormessage.test.ts for the new exceed/context/max_tokens variants.
Added changelog entry under 2026.2.22 (Unreleased) -> Fixes with contributor credits.

Given this, this should remain the canonical overflow-pattern PR. #6353 has been closed as duplicate with credit preserved.

…k to user (openclaw#20539) * fix: detect additional context overflow error patterns to prevent leak to user Fixes openclaw#9951 The error 'input length and max_tokens exceed context limit: 170636 + 34048 > 200000' was not caught by isContextOverflowError() and leaked to users via formatAssistantErrorText()'s invalidRequest fallback. Add three new patterns to isContextOverflowError(): - 'exceed context limit' (direct match) - 'exceeds the model\'s maximum context' - max_tokens/input length + exceed + context (compound match) These are now rewritten to the friendly context overflow message. * Overflow: add regression tests and changelog credits * Update CHANGELOG.md * Update pi-embedded-helpers.isbillingerrormessage.test.ts --------- Co-authored-by: echoVic <AkiraVic@outlook.com> Co-authored-by: Vincent Koc <vincentkoc@ieee.org>

…k to user (openclaw#20539) * fix: detect additional context overflow error patterns to prevent leak to user Fixes openclaw#9951 The error 'input length and max_tokens exceed context limit: 170636 + 34048 > 200000' was not caught by isContextOverflowError() and leaked to users via formatAssistantErrorText()'s invalidRequest fallback. Add three new patterns to isContextOverflowError(): - 'exceed context limit' (direct match) - 'exceeds the model\'s maximum context' - max_tokens/input length + exceed + context (compound match) These are now rewritten to the friendly context overflow message. * Overflow: add regression tests and changelog credits * Update CHANGELOG.md * Update pi-embedded-helpers.isbillingerrormessage.test.ts --------- Co-authored-by: echoVic <AkiraVic@outlook.com> Co-authored-by: Vincent Koc <vincentkoc@ieee.org> (cherry picked from commit 69692d0) # Conflicts: # CHANGELOG.md # src/agents/pi-embedded-helpers.isbillingerrormessage.test.ts

…k to user (openclaw#20539) * fix: detect additional context overflow error patterns to prevent leak to user Fixes openclaw#9951 The error 'input length and max_tokens exceed context limit: 170636 + 34048 > 200000' was not caught by isContextOverflowError() and leaked to users via formatAssistantErrorText()'s invalidRequest fallback. Add three new patterns to isContextOverflowError(): - 'exceed context limit' (direct match) - 'exceeds the model\'s maximum context' - max_tokens/input length + exceed + context (compound match) These are now rewritten to the friendly context overflow message. * Overflow: add regression tests and changelog credits * Update CHANGELOG.md * Update pi-embedded-helpers.isbillingerrormessage.test.ts --------- Co-authored-by: echoVic <AkiraVic@outlook.com> Co-authored-by: Vincent Koc <vincentkoc@ieee.org>

openclaw-barnacle bot added agents Agent runtime and tooling size: XS labels Feb 19, 2026

echoVic and others added 2 commits February 23, 2026 09:38

Overflow: add regression tests and changelog credits

bceb7ab

vincentkoc force-pushed the fix/context-overflow-detection-gap branch from 3e36a0f to bceb7ab Compare February 23, 2026 14:40

openclaw-barnacle bot added the trusted-contributor label Feb 23, 2026

vincentkoc mentioned this pull request Feb 23, 2026

fix(agents): detect Anthropic 'exceed context limit' error for auto-compaction #6353

Closed

vincentkoc added the dedupe:parent Primary canonical item in dedupe cluster label Feb 23, 2026

vincentkoc added 2 commits February 23, 2026 10:02

Update CHANGELOG.md

0784de5

Update pi-embedded-helpers.isbillingerrormessage.test.ts

674aaf5

vincentkoc merged commit 69692d0 into openclaw:main Feb 23, 2026
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vabole mentioned this pull request Feb 23, 2026

ops: decision needed for upstream sync (3 disputed files) vabole/openclaw#3

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This was referenced Feb 23, 2026

fix: display rate limit errors correctly instead of as context overflow #8661

Closed

[Bug]: Context overflow error #5771

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github-actions bot mentioned this pull request Feb 23, 2026

📡 Upstream Digest — 2026-02-23 16:45 UTC curtismercier/openclaw-mods#110

Open

arjunaskykok mentioned this pull request Feb 26, 2026

fix/test a2ui bundle preflight #27345

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2 tasks

github-actions bot mentioned this pull request Mar 1, 2026

cherry-pick: upstream bugfix commits (2026-03-01-0443) hughdidit/DAISy-Agency#140

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fix: detect additional context overflow error patterns to prevent leak to user#20539

fix: detect additional context overflow error patterns to prevent leak to user#20539
vincentkoc merged 4 commits intoopenclaw:mainfrom
echoVic:fix/context-overflow-detection-gap

echoVic commented Feb 19, 2026 •

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Greptile Summary

Confidence Score: 5/5

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vincentkoc commented Feb 23, 2026

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echoVic commented Feb 19, 2026 •

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