Bug type
Regression (worked before, now fails)
Beta release blocker
No
Summary
Bug Report: Empty responses from OpenAI-compatible models with reasoning
I'm seeing empty responses ("⚠️ Agent couldn't generate a response") from self-hosted OpenAI-compatible models with reasoning enabled. Sessions run successfully on the backend but deliver nothing to the user.
Root cause:
Commit f66b1d1 (May 10) — "fix: strip OpenAI-compatible replay reasoning" — changed reasoning stripping from Gemma4-only to ALL openai-completions models by default. Any model using openai-completions API now has historical reasoning blocks stripped on replay unless the provider explicitly opts out via dropReasoningFromHistory: false.
Commit e7277b4 (May 8) — "refactor(agents): preserve raw reasoning stream and push formatting to edge" — keeps reasoning deltas raw internally instead of pre-formatting them.
The interaction issue:
Models that output reasoning/thinking content in a raw format get their content mangled when replayed. The core sends the raw reasoning stream, but the replay sanitizer (via the new default) strips it. On some backends this causes the content block parser to fail — the model output gets placed entirely inside a thinking block instead of proper thinking + text separation. The result is an empty user-facing response.
Workaround:
Set "dropReasoningFromHistory": false in the provider config. This matches what DeepSeek and ZAI already do:
"my-provider": {
"api": "openai-completions",
"dropReasoningFromHistory": false,
...
}
Suggested fix:
The blanket openai-completions default stripping is too broad. Either:
- Only apply dropReasoningFromHistory: true to models known to fail on replayed reasoning (e.g., Gemma 4), or
- Let individual provider plugins declare their own default instead of inheriting a universal one
Anyone else hitting empty responses from self-hosted reasoning models since the May releases?
Steps to reproduce
Models that output reasoning/thinking content in a raw format get their content mangled when replayed. The core sends the raw reasoning stream, but the replay sanitizer (via the new default) strips it. On some backends this causes the content block parser to fail — the model output gets placed entirely inside a thinking block instead of proper thinking + text separation. The result is an empty user-facing response.
Expected behavior
not an empty response.
Actual behavior
Agent couldn't generate a response. Note: some tool actions may have already been executed — please verify before retrying.
OpenClaw version
2026.5.7
Operating system
macos
Install method
npm
Model
kimi 2.6
Provider / routing chain
sglang
Additional provider/model setup details
No response
Logs, screenshots, and evidence
Impact and severity
No response
Additional information
No response
Bug type
Regression (worked before, now fails)
Beta release blocker
No
Summary
Bug Report: Empty responses from OpenAI-compatible models with reasoning
I'm seeing empty responses ("⚠️ Agent couldn't generate a response") from self-hosted OpenAI-compatible models with reasoning enabled. Sessions run successfully on the backend but deliver nothing to the user.
Root cause:
Commit f66b1d1 (May 10) — "fix: strip OpenAI-compatible replay reasoning" — changed reasoning stripping from Gemma4-only to ALL openai-completions models by default. Any model using openai-completions API now has historical reasoning blocks stripped on replay unless the provider explicitly opts out via dropReasoningFromHistory: false.
Commit e7277b4 (May 8) — "refactor(agents): preserve raw reasoning stream and push formatting to edge" — keeps reasoning deltas raw internally instead of pre-formatting them.
The interaction issue:
Models that output reasoning/thinking content in a raw format get their content mangled when replayed. The core sends the raw reasoning stream, but the replay sanitizer (via the new default) strips it. On some backends this causes the content block parser to fail — the model output gets placed entirely inside a thinking block instead of proper thinking + text separation. The result is an empty user-facing response.
Workaround:
Set "dropReasoningFromHistory": false in the provider config. This matches what DeepSeek and ZAI already do:
"my-provider": {
"api": "openai-completions",
"dropReasoningFromHistory": false,
...
}
Suggested fix:
The blanket openai-completions default stripping is too broad. Either:
Anyone else hitting empty responses from self-hosted reasoning models since the May releases?
Steps to reproduce
Models that output reasoning/thinking content in a raw format get their content mangled when replayed. The core sends the raw reasoning stream, but the replay sanitizer (via the new default) strips it. On some backends this causes the content block parser to fail — the model output gets placed entirely inside a thinking block instead of proper thinking + text separation. The result is an empty user-facing response.
Expected behavior
not an empty response.
Actual behavior
Agent couldn't generate a response. Note: some tool actions may have already been executed — please verify before retrying.
OpenClaw version
2026.5.7
Operating system
macos
Install method
npm
Model
kimi 2.6
Provider / routing chain
sglang
Additional provider/model setup details
No response
Logs, screenshots, and evidence
Impact and severity
No response
Additional information
No response