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: Exotel
providerId: exotel
created: '2026-07-12'
modified: '2026-07-12'
reconciled: false
tags:
- Cloud Telephony
- Voice
- SMS
- CPaaS
- Rate Limiting
- Quotas
description: >-
  Exotel documents a per-minute throughput cap on its Voice APIs and returns
  HTTP 429 when exceeded. Its developer docs state Voice APIs are limited to
  around 200 calls per minute. SMS and other product limits are governed by
  account plan, sender/DLT approvals, and telecom regulations rather than a
  single published per-endpoint number. Values here are grounded where the
  docs state a figure and flagged otherwise.
notes: >-
  Only the ~200 calls/minute Voice API figure is explicitly documented in the
  reviewed pages. SMS throughput, campaign concurrency, and per-account
  quotas depend on plan and regulatory (DLT) approvals; verify current limits
  with Exotel support or the dashboard during reconciliation.
sources:
- https://developer.exotel.com/api
- https://developer.exotel.com/api/make-a-call-api
- https://developer.exotel.com/docs/faqs/pricing-plans
responseCodes:
  throttled: 429
limits:
- name: Voice API Calls
  scope: account
  metric: requests
  limit: ~200 per minute
  notes: Documented cap on Voice APIs; exceeding it returns HTTP 429.
- name: Bulk SMS Batch Size
  scope: request
  metric: messages
  limit: up to 100 messages per request
  notes: Bulk SMS (static/dynamic) accepts up to 100 messages per call per docs.
- name: SMS Body Length
  scope: request
  metric: characters
  limit: up to 2000 characters
  notes: Documented maximum SMS Body length.
- name: AgentStream Session Duration
  scope: stream
  metric: minutes
  limit: up to 60 minutes per streaming session
  notes: Documented max WebSocket voice-streaming session length; plan-dependent.
- name: Account / Plan Quotas
  scope: account
  metric: usage
  limit: per plan
  notes: Not published numerically; governed by plan and DLT/sender approvals.
policies:
- name: Throttling Response
  description: Requests over the documented Voice API rate return HTTP 429; back off and retry.
- name: Backoff Strategy
  description: Clients should implement exponential backoff with jitter on 429 responses.
- name: Streaming Timeout
  description: If a bot server does not respond within ~10 seconds during an AgentStream session, the session fails.
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com