PR #63635: fix: preserve content when stripping final tags in SSE streaming

• Repository: openclaw/openclaw
• Author: zozo123
• State: closed | merged: False
• Link: https://github.com/openclaw/openclaw/pull/63635

Description (problem / solution / changelog)

Summary

Fixes SSE streaming response corruption caused by the /v1/chat/completions handler silently dropping content when <final>/<think> tags straddle chunk boundaries.

Root cause: The upstream subscribe handler strips reasoning tags from streamed text. When a tag is split across chunks, it first emits a delta with a partial tag remnant and then, once the full tag is recognised in the accumulated buffer, emits a replace event (replace: true, delta: "") whose text field carries the corrected full content. The SSE handler only looked at delta, so replace events with an empty delta were silently discarded, causing entire response lines to vanish.

Fix: Track the accumulated text already sent to the SSE client and always derive the incremental content from the authoritative text field (the full cleaned buffer) rather than the per-chunk delta. This prevents both partial tag remnants from leaking and content from being silently dropped on replace events.

Closes #63325

Changes

• Modified src/gateway/openai-http.ts: Added accumulatedSent tracking and text-based delta derivation in the SSE streaming event handler
• Added regression test in src/gateway/openai-http.test.ts covering the replace-event scenario

Testing

• Added e2e test simulating partial <final> tag split across chunks with a replace event
• All existing tests pass (TypeScript type-check, oxlint, and pre-commit hooks all pass)
• Verified backward compatibility: events with only delta (no text) still work via fallback path

This PR was generated with AI assistance (Claude).

Changed files

• src/gateway/openai-http.test.ts (modified, +61/-0)
• src/gateway/openai-http.ts (modified, +47/-1)
• ui/src/ui/chat-model-ref.ts (modified, +1/-1)

PR #63894: fix: preserve content when stripping final tags in SSE streaming

• Repository: openclaw/openclaw
• Author: zozo123
• State: closed | merged: False
• Link: https://github.com/openclaw/openclaw/pull/63894

Description (problem / solution / changelog)

Summary

The /v1/chat/completions SSE streaming path dropped response content when <final>/<think> tags straddled chunk boundaries. The upstream handler detects cross-boundary tags and emits replace events with corrected full text, but the SSE handler only looked at delta, silently discarding replace events with empty deltas.

Closes #63325

Changes

• Track accumulated sent text via accumulatedSent in the SSE streaming handler
• Derive incremental SSE deltas from the authoritative text field instead of raw delta
• Use common-prefix matching on replace events to avoid duplicating already-sent content
• Added test covering replace events during final-tag stripping

Testing

• New test: preserves content when upstream emits replace events during final-tag stripping
• Verifies no content loss and no duplication on replace events

This PR was developed with AI assistance (Claude). Built with islo.dev

Changed files

• src/gateway/openai-http.test.ts (modified, +53/-0)
• src/gateway/openai-http.ts (modified, +24/-1)