Request contract

GET /api/v1/portfolio/performance. Retrieve tracked portfolio snapshots and performance adjusted for known deposits, withdrawals and connection-scope changes. Send the personal token in X-API-Key and keep it outside browser code and public logs.

Response and metering

The result includes range, value points, return metrics and coverage information needed to qualify the number. Successful metered responses publish X-Credit-Cost and X-Credits-Remaining so usage can be recorded without another request.

Production behavior

Longer ranges cost more: the multiplier grows from short windows to ALL. Inspect current costs from the usage endpoint. Handle application/problem+json errors by stable code, preserve the correlation ID and never retry a mutation unless the workflow is idempotent.