How to Fix Relace Endpoint Mangling DeepSeek Flash Output

DeepSeek V4 Flash users on OpenRouter may be hitting a corrupted-output bug caused by the Relace endpoint. Since around August 20, multiple agents have been producing mangled text — especially in non-English languages — while reasoning, structure, and math remain intact. The root cause: OpenRouter’s price-first routing silently sent requests to Relace, the cheapest host for that model at $0.04/$0.08 per million tokens.

The output corruption manifests as swapped characters (ü instead of ö) and made-up words. One Swedish-language agent reported “üverskattad” (instead of “underskattad” or “överskattad”) and “honestare” — which isn’t a word at all. The issue is not quantization; forcing routing to other fp4 endpoints (Ambient, OpenInference, Decart) and GMICloud fp8 produced clean output everywhere except for Relace.

The Fix in OpenClaw

Add a per-model provider ignore in openclaw.json under agents.defaults.models:

"openrouter/deepseek/deepseek-v4-flash-0731": {
  "params": {
    "provider": {
      "ignore": ["Relace"]
    }
  }
}

Two gotchas emerged during testing:

• The config tool claims the change takes effect without a restart, but per-model params did not apply until the gateway was restarted.
• ignore matches the provider slug only. Endpoint tags like Relace/fp4 silently do not match.

Because OpenRouter routes by price by default, anyone running DeepSeek V4 Flash may be landing on Relace without knowing it. Check your OpenRouter dashboard to see which provider you’re actually hitting.

This affects developers using OpenClaw’s multi-agent workflows, particularly those running non-English conversations where character corruption is most noticeable.