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: HAProxy
providerId: haproxy
generated: '2026-08-28'
method: searched
source: >-
  openapi/haproxy-data-plane-api-openapi.yml and
  https://www.haproxy.com/documentation/haproxy-data-plane-api/
created: '2026-05-04'
modified: '2026-08-28'
tags:
  - High Availability
  - Load Balancing
  - Networking
  - Reverse Proxy
  - Rate Limiting
limit_count: 0
description: >-
  The HAProxy Data Plane API publishes no rate limits, and structurally cannot have any:
  it is self-hosted software running on the operator's own machine, with no vendor quota
  layer, no API key and no account. This file previously carried a bulk-sweep scaffold
  inventing free/professional/enterprise request quotas and X-RateLimit-* headers; none of
  that exists and it has been removed. Searched the contract and the documentation
  2026-08-28: no X-RateLimit-*, no RateLimit-*, and no Retry-After is declared on any of
  the 557 operations.
headers: {}
limits: []
throttling:
  request_rate: none
  detail: >-
    Throughput is bounded by the host the Data Plane API runs on and by the dataplaneapi
    process flags (--read-timeout, --write-timeout, --keep-alive, --cleanup-timeout), not
    by a quota.
concurrency_limits:
  - name: Open transactions
    scope: instance
    status: 429
    message: Too many open transactions
    detail: >-
      The only 429 in the entire contract. It is a limit on how many configuration
      transactions may be open at once, not on request rate. It appears on 2 operations
      (startTransaction and startSpoeTransaction). Recovery is to commit or delete open
      transactions, not to back off and retry — waiting does not clear it, because an
      abandoned transaction never expires on its own.
    recovery: GET /v3/services/haproxy/transactions, then DELETE the strays.
related:
  - >-
    Do not confuse this with HAProxy's rate-limiting FEATURES. HAProxy is one of the most
    widely used tools for imposing rate limits on other people's traffic (stick tables,
    http-request deny, global rate limiting in HAProxy Enterprise). That is what the product
    does for its users; it is not a limit the product imposes on callers of this API.
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com