Bug type

Regression (worked before, now fails)

Summary

Using Mistral AI with a valid API key below rate limit fails within seconds at error code 422.

Steps to reproduce

1. Setup Openclaw with Mistral as the provider.
2. Hatch the agent.
3. Attempt to send a message.

Expected behavior

The model should respond normally.

Actual behavior

Connects for two seconds, errors out with code 422.

OpenClaw version

2026.3.13

Operating system

Debian 12 Raspberry Pi OS

Install method

Package

Model

mistral-large-latest

Provider / routing chain

Openclaw->Mistral

Additional provider/model setup details

No response

Logs, screenshots, and evidence

Impact and severity

Affected: Anybody who wants to use Mistral with Openclaw (Arguably Mistral is the most generous free tier API)
Severity: Completely blocks workflow and any chat.
Frequency: Every time you use Mistral.
Consequence: No chat, no agents, zip. zilch. nada.

Additional information

No response