specification: API Commons Rate Limits
specificationVersion: '0.1'
schema: https://raw.githubusercontent.com/api-evangelist/interface-research/main/schema/api-commons.yml#/$defs/RateLimits
provider: Omnisend
providerId: omnisend
generated: '2026-08-13'
method: searched
source: https://api-docs.omnisend.com/reference/rate-limit-timeouts-errors
created: '2026-05-25'
modified: '2026-08-13'
reconciled: true
tags:
  - Rate Limiting
  - Quotas
  - Email Marketing
description: >-
  Published rate limits for the Omnisend API at version 2026-03-15, read from the provider's own
  rate-limit reference page and cross-checked against the per-operation "Rate Limiting" notes in
  llms.txt. Limits are enforced at the API gateway PER BRAND on a sliding window — every request made
  on behalf of the same brand counts toward the same budget regardless of which API key, OAuth token
  or integration sent it. The runtime signal is the finding: Omnisend publishes NO rate-limit
  response headers at all.
sources:
  - https://api-docs.omnisend.com/reference/rate-limit-timeouts-errors
  - https://api-docs.omnisend.com/llms.txt
  - https://api-docs.omnisend.com/reference/overview

algorithm: sliding-window
scope: per-brand
enforcement_point: API gateway
default_limit:
  rpm: 400
  note: Applies to every endpoint not named in the exceptions below.

responseCodes:
  throttled: 429
  quotaExceeded: 429
  conflict: 409

headers:
  rate_limit_headers_published: false
  x_ratelimit: null
  ratelimit: null
  retry_after: null
  note: >-
    NO rate-limit response headers are documented — no X-RateLimit-Limit/Remaining/Reset, no
    RFC-draft RateLimit-*, and no Retry-After. A client cannot see its remaining budget before it is
    exhausted. The only runtime signal is the 429 body.

throttled_response:
  status: 429
  media_type: application/json
  format: rfc9457
  body:
    type: https://problems.omnisend.com/rate-limit-exceeded
    title: Rate limit exceeded
    status: 429
    retryAfter: 'integer seconds — present on SOME endpoints only ("Some endpoints include a retryAfter field")'
  schema: RateLimitProblem (declared in every harvested OpenAPI contract)

limits:
  - resource: '*'
    endpoint: all endpoints (default)
    method: any
    rpm: 400
  - resource: segments
    endpoint: /segments
    method: [GET, DELETE]
    rpm: 100
  - resource: segments
    endpoint: /segments
    method: [POST, PUT]
    rpm: 15
    note: The strictest per-minute limit Omnisend publishes. Segment authoring must be batched, not looped.
  - resource: contacts
    endpoint: /contacts/tags
    method: [POST, DELETE]
    rpm: 60
    note: Bulk tag add/remove. Asynchronous — the tag may not be visible on the next read.
  - resource: email-templates
    endpoint: '/email-templates/{id}/render'
    method: POST
    rpm: 40
  - resource: email-content
    endpoint: '/email-content/{id}/render'
    method: POST
    rpm: 40
  - resource: analytics
    endpoint: [/analytics/reports, /analytics/statistics]
    method: POST
    rpm: 10
    daily: 55
    daily_window: 24 hours (sliding)
    note: The only endpoints with a daily quota. Up to 4 queries per request, so budget query batching accordingly.

payload_limits:
  - endpoint: POST /batches
    limit: 100 actions per batch
  - endpoint: POST /email-templates/import
    limit: 1 MB request body
    error: 413
  - endpoint: POST /email-content/{id} (PUT)
    limit: 1 MB request body
    error: 413
  - endpoint: [POST /images, POST /images/upload]
    limit: 5 MB per file
    formats: [JPEG, PNG, GIF, WebP]
    error: '413 (size), 415 (format)'
  - endpoint:
      - 'POST /campaigns/{id}/test-email'
      - 'POST /automations/{id}/blocks/{blockID}/test-email'
    limit: 5 recipients

pagination:
  style: cursor
  parameters: [limit, after, before]
  response_fields: [paging.limit, paging.hasMore, paging.cursors.after, paging.cursors.before]
  defaults:
    general: {default: 100, max: 250}
    email-templates: {default: 50, max: 100}

policies:
  - name: Sliding window
    description: The counter tracks requests over the last minute (or 24 hours for daily quotas) rather than resetting at fixed intervals, so bursts at window boundaries are not possible.
  - name: Per-brand aggregation
    description: All API keys, OAuth tokens and integrations acting for one brand share a single budget. A partner app and the merchant's own scripts throttle each other.
  - name: 429 handling
    description: Read `retryAfter` from the RFC 9457 body when present; otherwise back off exponentially. There is no header to read.
  - name: Prefer batches
    description: Omnisend recommends POST /batches explicitly as the way to avoid hitting rate limits on bulk work.
  - name: Building-state segments
    description: A segment in `building` state returns 409 Conflict for update and delete — a state error, not a rate-limit error.

error_logging:
  url: https://app.omnisend.com/integrations/api-access-logs
  path: Store Settings > API > API Issues
  note: Every API error for the brand is recorded in-app, which is the only per-request diagnostic surface Omnisend offers.

limit_count: 7