API Rate Limits and Deprecation Policy
vCard QR Code Generator publishes retry and throttling signals so AI agents can call the API safely.
Rate Limit Headers
JSON API responses include RFC-style rate limit headers and legacy aliases:
RateLimit-LimitandX-RateLimit-LimitRateLimit-RemainingandX-RateLimit-RemainingRateLimit-ResetandX-RateLimit-Reset
If a future protected endpoint returns 429, agents should wait for Retry-After seconds, then retry with exponential backoff.
Idempotency-Key
Mutation requests can include an optional Idempotency-Key header. The current vCard payload endpoint is deterministic and echoes the key when supplied so agents can correlate safe retries.
Versioning and Deprecation
The public API uses URL versioning under /v1/. Backward-incompatible changes will use a new version path. Deprecated endpoints will be documented here and in the OpenAPI spec before removal.
When an endpoint is scheduled for removal, responses may include Deprecation and Sunset headers plus a documentation link with migration guidance.