[Bug]: error when sending a request to x-ai/grok-4.1-fast via OpenRouter #32039
Description
Bug type
Regression (worked before, now fails)
Summary
After updating the code and building a new Docker image I started receiving the following error message:
openclaw-gateway-1 | 2026-03-02T18:16:59.139Z [agent/embedded] embedded run agent end: runId=a6e05b56-75c5-473d-9435-903b7ae7ded0 isError=true error=Invalid arguments passed to the model.
Using other models like google/gemini-3-flash-preview works well
Steps to reproduce
- configure OpenClaw with x-ai/grok-4.1-fast as primary model
"agents": {
"defaults": {
"model": {
"primary": "openrouter/x-ai/grok-4.1-fast",
Expected behavior
request is processed by the model and response received
Actual behavior
Error: Invalid arguments passed to the model
openclaw-gateway-1 | 2026-03-02T18:16:59.139Z [agent/embedded] embedded run agent end: runId=a6e05b56-75c5-473d-9435-903b7ae7ded0 isError=true error=Invalid arguments passed to the model.
OpenClaw version
2026.3.1
Operating system
Ubuntu 24.04
Install method
docker compose
Logs, screenshots, and evidence
Impact and severity
No response
Additional information
No response