generated: '2026-07-20'
method: derived
source:
  - grpc/momento-cacheclient.proto
  - grpc/momento-controlclient.proto
  - grpc/momento-httpcache.proto
  - https://docs.momentohq.com/cache/develop/api-reference/http-api
authentication:
  style: api-key
  transport: Authorization header (HTTP) / authorization gRPC metadata; also `?token=` query on HTTP API
  see: authentication/momento-authentication.yml
transport:
  primary: gRPC (HTTP/2)
  secondary: HTTP/1.1 JSON+binary API for cache get/set/delete
  streaming: server-streaming gRPC for Topics Subscribe and cache GetBatch/SetBatch
ttl:
  required_on_write: true
  units:
    grpc: ttl_milliseconds
    http: ttl_seconds
  note: Every cache Set specifies a TTL; a cache also has a configurable default TTL.
conditional_writes:
  supported: true
  operations: [SetIf, SetIfHash, SetIfNotExists (deprecated), Increment]
  note: >-
    Compare-and-set style conditional writes (present/absent/equal/not-equal, and hash-based
    variants) provide optimistic concurrency control. There is no client-supplied
    Idempotency-Key header; writes are addressed by key and are naturally idempotent by value.
pagination:
  style: cursor
  scope: control-plane (ListCaches, ListSigningKeys)
  request_param: next_token
  response_field: next_token
  note: Data-plane collection reads (ListFetch, DictionaryFetch, SetFetch, leaderboard ranges) are bounded per call (e.g. 8192 elements for leaderboards).
error_semantics:
  model: gRPC status codes mapped by SDKs to a stable MomentoErrorCode enum
  http_status: HTTP API returns standard codes (200 hit, 204 no content, 404 miss, 4xx/5xx errors)
  catalog: errors/momento-error-codes.yml
rate_limiting:
  model: per-cache request-rate, throughput, and item-size limits; per-cache topic publish-rate and subscription-count limits
  signal: LimitExceededError (with a limit-exceeded message tag) surfaced to clients
  source: grpc/momento-controlclient.proto (_CacheLimits, _TopicLimits)
versioning:
  scheme: single-version service; SDK/proto compatibility maintained additively
  note: Deprecated RPCs (e.g. SetIfNotExists) are marked `option deprecated = true` in the protobufs rather than versioned out.
request_tracing:
  note: gRPC metadata carries client type/version headers; no documented public request-id echo header.