Hardcoded patterns missing "free usage" / "usage exceeded"

[brucekinsey]

Plugin version

1.3.4

OpenCode version

1.15.0

What happened?

The plugin's hardcoded classifyError() function uses internal pattern lists (RATE_LIMIT_PATTERNS, QUOTA_PATTERNS, etc.) that don't include "free usage" or "usage exceeded". When a provider returns an error like "Free usage exceeded, subscribe to Go", classifyError returns "unknown", which isn't a valid fallbackOn category. This means the plugin never marks the model as rate_limited, and the proactive chat.message redirect never activates for this error.

I patched both DEFAULT_PATTERNS and QUOTA_PATTERNS locally to add "free usage" and "usage exceeded" — that fixed the issue. Would be great if these strings were included in the default/QUOTA patterns upstream.

What did you expect?

Errors containing "free usage" or "usage exceeded" should be classified as "quota_exceeded" and trigger the fallback chain without requiring a source code patch.

Your model-fallback.json config (redact sensitive values)

{"enabled":true,"defaults":{"fallbackOn":["rate_limit","quota_exceeded","5xx","timeout","overloaded"],"cooldownMs":300000,"retryOriginalAfterMs":600000,"maxFallbackDepth":3},"patterns":["free usage","usage exceeded","rate limit","ratelimit","usage limit","too many requests","quota exceeded","overloaded","capacity exceeded","credits exhausted","insufficient credit","billing limit","resource exhausted","429"],"agents":{"*":{"fallbackModels":["opencode-go/deepseek-v4-flash","opencode-go/qwen3.5-plus","opencode-go/minimax-m2.5"]}},"logging":true,"logLevel":"debug"}

Relevant log output

{"level":"debug","event":"retry.ignored","category":"unknown","messageLength":36}

The 36-char message was "Free usage exceeded, subscribe to Go".

Steps to reproduce

1. Configure a fallback chain
2. Use a model that returns "Free usage exceeded" or "usage exceeded" on exhaustion
3. Observe retry.ignored with category: "unknown" in the logs
4. The model is never marked rate_limited, so proactive redirect never activates

Operating system

Linux