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: Basecamp
providerId: basecamp
created: '2026-05-04'
# Provenance stamped 2026-08-11: this artifact was written by the API Evangelist
# bulk sweep dated 2026-05-04, not harvested from the provider. See roadmap#35.
method: generated
modified: '2026-05-05'
reconciled: true
tags:
  - Collaboration
  - Project Management
  - REST
  - SaaS
  - Team Communication
  - Rate Limiting
description: Basecamp's bc3-api enforces multiple rate limits simultaneously, scoped per IP address with
  separate windows for GET vs POST and per-second/hour/day buckets. The most commonly hit limit is 50
  requests per 10-second window per IP. Thresholds are dynamic and not published per-plan; integrators
  must handle backpressure rather than rely on static numbers.
sources:
  - https://github.com/basecamp/bc3-api
  - https://github.com/basecamp/bc3-api/blob/master/README.md
headers:
  retryAfter: Retry-After
responseCodes:
  throttled: 429
  serviceUnavailable: 503
limits:
  - name: Default per-IP throttle
    scope: IP
    metric: requests_per_10_seconds
    limit: 50
    timeFrame: 10-seconds
    notes: Most commonly encountered limit. Multiple per-second/hour/day limits operate concurrently and
      are dynamically adjusted by Basecamp.
  - name: Per-method dynamic limits
    scope: IP
    metric: varies
    limit: 'dynamic — separate buckets for GET and POST, per-second/hour/day'
    notes: Documentation does not publish the exact thresholds; clients must observe 429 + Retry-After
      and back off.
policies:
  - name: Backoff Strategy
    description: Implement exponential backoff with jitter and honor the Retry-After header on 429 responses.
  - name: Retry on 5xx
    description: 500, 502, 503, and 504 responses should be retried with exponential backoff. Do not retry
      404s automatically.
  - name: Dynamic Backpressure
    description: Basecamp explicitly warns thresholds adjust dynamically. Treat rate limits as observed
      runtime signals rather than static configuration.
  - name: User-Agent Identification
    description: Basecamp requires a descriptive User-Agent header identifying the integration; missing/anonymous
      User-Agents may be blocked before rate limiting applies.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com