# HAProxy

> HAProxy is a free, very fast and reliable reverse proxy offering high availability, load
> balancing and proxying for TCP and HTTP-based applications. HAProxy Technologies builds the
> commercial products around it — HAProxy Enterprise, HAProxy ALOHA, HAProxy Fusion and the
> HAProxy Kubernetes Ingress Controller. The programmable surface is the Data Plane API, a
> self-hosted REST API for managing HAProxy configuration and runtime state without a restart.

Generated by API Evangelist from apis.yml and this repository's artifacts on 2026-08-28.
HAProxy does not publish an llms.txt of its own; this file is generated, not harvested.

## APIs

- [HAProxy Data Plane API](https://www.haproxy.com/documentation/haproxy-data-plane-api/): REST API for
  managing HAProxy configuration dynamically — frontends, backends, servers, ACLs, rules, TLS
  material and runtime state. Swagger 2.0 contract, 223 paths, 557 operations, 232 definitions,
  version 3.4. Self-hosted: it runs beside your HAProxy instance and listens on port 5555 by
  default under base path /v3. HTTP Basic authentication against a userlist.
- [HAProxy Runtime API](https://www.haproxy.com/documentation/haproxy-runtime-api/): the socket
  interface (formerly the stats socket) for live changes — enable/disable servers, adjust weights,
  read stick tables and statistics. Reachable over a UNIX socket or a TCP/IP socket, not over HTTP.
  The Data Plane API exposes 26 of these operations over HTTP under /v3/services/haproxy/runtime.
- [HAProxy Kubernetes Ingress Controller](https://www.haproxy.com/documentation/kubernetes-ingress/):
  implements Kubernetes Ingress and Gateway API routing. Its API surface is the Kubernetes API
  itself, under the custom resource group ingress.v3.haproxy.org.

## Contract

- [Data Plane API OpenAPI (Swagger 2.0)](openapi/haproxy-data-plane-api-openapi.yml)
- Upstream source: https://raw.githubusercontent.com/haproxytech/client-native/master/specification/build/haproxy_spec.yaml
- A running instance serves its own contract at GET /v3/specification and an OpenAPI 3 rendering
  at GET /v3/specification_openapiv3.

## How to call it

- Base URL: http://{haproxy-host}:5555/v3 (port and base path are the documented defaults)
- Auth: HTTP Basic, credentials defined in the HAProxy userlist referenced by the Data Plane API
  configuration. No OAuth, no API keys, no scopes.
- Writes take an optimistic-concurrency `version` query parameter that must match the current
  configuration version, read from GET /v3/services/haproxy/configuration/version. A stale version
  returns 409.
- Alternatively batch writes in a transaction: POST /v3/services/haproxy/transactions to open one,
  PUT /v3/services/haproxy/transactions/{id} to commit, DELETE the same path to roll back. Inside a
  transaction the individual calls do not carry a version.
- Responses carry a Configuration-Version header; a change that triggers a reload returns 202 with
  a Reload-ID header.
- Errors are a JSON object with `code` and `message`.

## Artifacts in this profile

- [Authentication](authentication/haproxy-authentication.yml)
- [Conventions and reversibility](conventions/haproxy-conventions.yml)
- [Error catalog](errors/haproxy-problem-types.yml)
- [Data model](data-model/haproxy-data-model.yml)
- [Lifecycle and versioning](lifecycle/haproxy-lifecycle.yml)
- [Changelog](changelog/haproxy-changelog.yml)
- [CLI](cli/haproxy-cli.yml)
- [Packages and distribution](packages/haproxy-packages.yml)
- [Conformance](conformance/haproxy-conformance.yml)
- [Agent skills](skills/_index.yml)
- [MCP](mcp/haproxy-mcp.yml)
- [Rate limits](rate-limits/haproxy-rate-limits.yml)
- [Plans and pricing](plans/haproxy-plans-pricing.yml)

## Optional

- [Documentation](https://docs.haproxy.org/)
- [Community forum](https://discourse.haproxy.org/)
- [Blog](https://www.haproxy.com/blog/)
- [GitHub — upstream HAProxy](https://github.com/haproxy)
- [GitHub — HAProxy Technologies](https://github.com/haproxytech)