generated: '2026-07-21'
method: derived
source: grpc/ protobuf definitions
note: >-
  Cross-cutting request/response conventions derived from the archived Speechly
  gRPC definitions. Speechly was a gRPC-first API (with optional HTTP transcoding
  via google.api.annotations); conventions reflect gRPC semantics rather than
  REST. The hosted API is discontinued.
protocol:
  primary: grpc
  http_transcoding: true
  http_transcoding_note: >-
    speechly/config protos import google/api/annotations.proto, enabling
    grpc-gateway HTTP/JSON transcoding for the Config surface.
authentication:
  style: bearer-token-metadata
  flow: >-
    Call IdentityAPI.Login(device_id, scope=application|project) to obtain a
    short-lived access token, then present it as the gRPC Authorization bearer
    credential in call metadata on all subsequent SLU/WLU/Batch/Config/
    Analytics/Moderation calls.
  cross_ref: authentication/speechly-authentication.yml
idempotency:
  supported: false
  note: >-
    No idempotency-key mechanism is defined in the protobuf definitions. Config
    mutations (CreateApp/UpdateApp/DeleteApp) are plain unary RPCs without an
    idempotency contract.
pagination:
  supported: false
  note: >-
    ListApps/ListBaseModels/ListLanguages return full repeated collections with
    no cursor/offset/page-token parameters in the proto definitions.
streaming:
  supported: true
  patterns:
    - SLU.Stream (bidirectional streaming SLU)
    - ModerationAPI.StreamingAudioModeration (client streaming audio moderation)
  note: >-
    Streaming RPCs carry a leading config message (e.g. SLUConfig) followed by
    audio chunks; responses interleave transcript, entity, intent and segment
    events.
versioning:
  scheme: package-path
  note: >-
    Versions are encoded in the protobuf package path (speechly.slu.v1,
    speechly.slu.v2beta1, speechly.identity.v2, speechly.moderation.v1beta1).
  cross_ref: lifecycle/speechly-lifecycle.yml
error_envelope:
  style: grpc-status
  note: >-
    Errors surface as gRPC status codes/messages. The SLU stream additionally
    carries an in-band SLUError message for recognition-level failures. No
    RFC 9457 problem+json envelope is used.
  cross_ref: conformance/speechly-conformance.yml
rate_limit_signaling:
  supported: unknown
  note: Not documented in the protobuf definitions.