Client Attribution

Segmenting traffic and identifying upstream clients via the appname field.

appname is an optional field in ONR access logs. It is intended for observability: segment traffic by client app/tool without changing routing behavior.

Resolution order

ONR resolves appname for logging in this order:

1. Request header appname (trimmed; if non-empty, it always wins)
2. If enabled, infer from User-Agent
3. Fallback to logging.appname_infer.unknown (trimmed). If empty, appname is omitted from the log record.

Enable inference

Configure it in onr.yaml:

logging:
  appname_infer:
    enabled: true
    unknown: "unknown-client"

Inference behavior

Inference is a best-effort substring match against the lowercased User-Agent. It returns a normalized app name when it finds a known keyword.

Current builtin keywords include common tools/SDKs such as:

• claude-code
• cursor
• windsurf
• cline
• aider
• continue
• openai-sdk (for example openai-python, openai-node, openai-go)
• anthropic-sdk

If you want stable attribution, set the appname header explicitly instead of relying on inference.

Example

curl -sS http://127.0.0.1:3300/v1/models \
  -H "Authorization: Bearer change-me" \
  -H "appname: my-service"