generated: '2026-07-21' method: searched source: https://domains.opensrs.guide/docs/quickstart docs: - https://domains.opensrs.guide/docs/quickstart - https://domains.opensrs.guide/docs/protocol-message-structure - https://domains.opensrs.guide/docs/codes api: OpenSRS Domains and TLS/SSL API transport: style: XML-over-HTTPS-POST (proprietary OPS protocol, not REST) endpoint_live: https://rr-n1-tor.opensrs.net:55443 endpoint_test: https://horizon.opensrs.net:55443 content_type: text/xml message_structure: >- An OPS XML envelope with a

and a ; the body carries a data_block of key/value pairs, dt_assoc (associative) and dt_array structures. Each request names an `action` (e.g. lookup, sw_register) and an `object` (e.g. domain, trust_service). authentication: style: request-signing headers: [X-Username, X-Signature] signature: double-MD5 of the XML body with the reseller API key see: authentication/tucows-authentication.yml idempotency: supported: false note: >- OpenSRS does not expose an Idempotency-Key header. For asynchronous registries it instead guards against duplicate work with server-side state: a concurrent request on the same domain returns code 437, an entity already in a processing state returns 486 (retry after a short delay), and a duplicate renewal returns 555. Callers should treat these codes as "already-in-flight / already-done" rather than retrying blindly. pagination: style: date-range / bounded queries note: >- List operations are bounded rather than cursor-paginated. `get (domain)` with type=list accepts a page/limit and an expiry date range; `get_domains_by_expiredate` returns domains expiring within an explicit start/end date window. rate_limiting: signals: - code 300 (Exceeded max command rate; request deferred) - code 310 (Exceeded max simultaneous connections) - code 350 (max 100 commands per connection, then re-authenticate) connection_lifetime: >- A connection stays open no more than 60 seconds; authentication plus the request must complete within that window or the connection is closed. note: No numeric X-RateLimit headers are documented; limits surface as response codes. error_envelope: style: response_code + response_text in the XML body http_status: 200 for well-formed protocol responses see: errors/tucows-problem-types.yml versioning: scheme: guide-versioned (documentation labelled v1.0); the wire protocol is stable/unversioned events: supported: true style: domain event notifications (e.g. registrant_verification_status_change) see: asyncapi/tucows-opensrs-domains-events.yml