Caddy website screenshot

Caddy

Caddy is a modern, extensible, open-source web server and reverse proxy written in Go that provides automatic HTTPS via Let's Encrypt, a dynamic JSON-based admin API, a human-friendly Caddyfile configuration format, and a modular architecture with a rich ecosystem of plugins for authentication, observability, and custom behavior.

Caddy publishes 5 APIs on the APIs.io network, including Adapt API, Configuration API, Lifecycle API, and 2 more. Tagged areas include Automatic HTTPS, Go, Load Balancer, Reverse Proxy, and TLS.

Caddy’s developer surface includes documentation and 7 more developer resources.

🌐 Visit website 📡 Source on GitHub
30.4/100 thin ▬ flat Agent 22/100 agent aware Full breakdown ↓
scored 2026-07-28 · rubric v0.6
AccessFreemium
6 APIs
Automatic HTTPSGoLoad BalancerReverse ProxyTLSWeb Server

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-07-28 · rubric v0.6
Composite quality — 30.4/100 · thin
Contract Quality 9.5 / 25
Developer Ergonomics 1.7 / 20
Commercial Clarity 7.9 / 20
Operational Transparency 4.8 / 13
Governance 0.0 / 12
Discoverability 6.5 / 10
Agent readiness — 22/100 · agent aware
Machine-Readable Contract 18 / 18
Agentic Access Contract 10 / 10
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 7 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3
A2A Agent Card 0 / 8
Dry-Run / Simulate Mode 0 / 4
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. This rating is computed from github.com/api-evangelist/caddy: open an issue to ask a question, or submit a pull request to add artifacts. Want it done for you? Prioritized profiling — $2,500 →

APIs 6

Individual APIs this provider publishes, each with its own machine-readable definition.

Caddy Admin API

Caddy exposes a RESTful administration API on localhost:2019 by default for dynamically loading and modifying server configuration at runtime without restarts. Endpoints support...

Caddy Adapt API

The Adapt API from Caddy — 1 operation(s) for adapt.

Caddy Configuration API

The Configuration API from Caddy — 1 operation(s) for configuration.

Caddy Lifecycle API

The Lifecycle API from Caddy — 2 operation(s) for lifecycle.

Caddy PKI API

The PKI API from Caddy — 2 operation(s) for pki.

Caddy Reverse Proxy API

The Reverse Proxy API from Caddy — 1 operation(s) for reverse proxy.

Open Collections 1

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Caddy Admin API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Caddy Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Caddy Rate Limits

5 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Caddy Finops

FINOPS

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Caddy Domain Security

TLSv1.3 · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Caddy Agentic Access

11 operations · 7 acting · 1 human-in-the-loop

11 operations · 7 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation
Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess
AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization
GitHubOrganization

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity
DomainSecurity

Operate 1

Status, limits, changes, and where to get help

Community Forum
Community Forum

Company 1

The organization behind the API

Website
Website

Other 2

Properties that don't map to a standard resource type

Download
Download
 Sponsors
Sponsors

Source (apis.yml)

apis.yml Raw ↑ 
aid: caddy
name: Caddy
description: Caddy is a modern, extensible, open-source web server and reverse proxy written in Go that provides automatic
  HTTPS via Let's Encrypt, a dynamic JSON-based admin API, a human-friendly Caddyfile configuration format, and a modular
  architecture with a rich ecosystem of plugins for authentication, observability, and custom behavior.
type: Index
kind: opensource
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
position: Consumer
access: Open Source
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/caddy.png
tags:
- Automatic HTTPS
- Go
- Load Balancer
- Reverse Proxy
- TLS
- Web Server
url: https://raw.githubusercontent.com/api-evangelist/caddy/refs/heads/main/apis.yml
created: '2026-03-27'
modified: '2026-05-19'
specificationVersion: '0.19'
apis:
- aid: caddy:caddy-admin-api
  name: Caddy Admin API
  description: Caddy exposes a RESTful administration API on localhost:2019 by default for dynamically loading and modifying
    server configuration at runtime without restarts. Endpoints support loading full JSON configs, traversing and mutating
    specific config paths, adapting Caddyfile to JSON, and querying PKI and reverse proxy state.
  humanURL: https://caddyserver.com/docs/api
  baseURL: http://localhost:2019
  tags:
  - Admin API
  - Configuration
  - REST
  properties:
  - type: Documentation
    url: https://caddyserver.com/docs/api
  - type: JSON Config Structure
    url: https://caddyserver.com/docs/json/
  - type: Modules Reference
    url: https://caddyserver.com/docs/modules/
  - type: API Tutorial
    url: https://caddyserver.com/docs/api-tutorial
  x-features:
  - POST /load for full config replacement
  - GET/POST/PUT/PATCH/DELETE /config/[path] for granular updates
  - POST /adapt to convert Caddyfile to JSON without loading
  - POST /stop for graceful shutdown
  - GET /pki/ca/{id} for internal CA inspection
  - GET /reverse_proxy/upstreams for upstream status
  - ETag and If-Match concurrency control
  x-use-cases:
  - Dynamic configuration in orchestrated environments
  - Multi-tenant SaaS with per-tenant routes
  - Zero-downtime config changes
  - Integration with service discovery
  - Observability of upstream health
- aid: caddy:caddy-adapt-api
  name: Caddy Adapt API
  description: The Adapt API from Caddy — 1 operation(s) for adapt.
  humanURL: https://caddyserver.com/
  baseURL: http://localhost:2019
  tags:
  - Adapt
  properties:
  - type: OpenAPI
    url: openapi/caddy-adapt-api-openapi.yml
  - type: Documentation
    url: https://caddyserver.com/docs/
  - type: GettingStarted
    url: https://caddyserver.com/docs/getting-started
  - type: GitHubRepository
    url: https://github.com/caddyserver/caddy
  - type: Download
    url: https://caddyserver.com/download
- aid: caddy:caddy-configuration-api
  name: Caddy Configuration API
  description: The Configuration API from Caddy — 1 operation(s) for configuration.
  humanURL: https://caddyserver.com/
  baseURL: http://localhost:2019
  tags:
  - Configuration
  properties:
  - type: OpenAPI
    url: openapi/caddy-configuration-api-openapi.yml
  - type: Documentation
    url: https://caddyserver.com/docs/
  - type: GettingStarted
    url: https://caddyserver.com/docs/getting-started
  - type: GitHubRepository
    url: https://github.com/caddyserver/caddy
  - type: Download
    url: https://caddyserver.com/download
- aid: caddy:caddy-lifecycle-api
  name: Caddy Lifecycle API
  description: The Lifecycle API from Caddy — 2 operation(s) for lifecycle.
  humanURL: https://caddyserver.com/
  baseURL: http://localhost:2019
  tags:
  - Lifecycle
  properties:
  - type: OpenAPI
    url: openapi/caddy-lifecycle-api-openapi.yml
  - type: Documentation
    url: https://caddyserver.com/docs/
  - type: GettingStarted
    url: https://caddyserver.com/docs/getting-started
  - type: GitHubRepository
    url: https://github.com/caddyserver/caddy
  - type: Download
    url: https://caddyserver.com/download
- aid: caddy:caddy-pki-api
  name: Caddy PKI API
  description: The PKI API from Caddy — 2 operation(s) for pki.
  humanURL: https://caddyserver.com/
  baseURL: http://localhost:2019
  tags:
  - PKI
  properties:
  - type: OpenAPI
    url: openapi/caddy-pki-api-openapi.yml
  - type: Documentation
    url: https://caddyserver.com/docs/
  - type: GettingStarted
    url: https://caddyserver.com/docs/getting-started
  - type: GitHubRepository
    url: https://github.com/caddyserver/caddy
  - type: Download
    url: https://caddyserver.com/download
- aid: caddy:caddy-reverse-proxy-api
  name: Caddy Reverse Proxy API
  description: The Reverse Proxy API from Caddy — 1 operation(s) for reverse proxy.
  humanURL: https://caddyserver.com/
  baseURL: http://localhost:2019
  tags:
  - Reverse Proxy
  properties:
  - type: OpenAPI
    url: openapi/caddy-reverse-proxy-api-openapi.yml
  - type: Documentation
    url: https://caddyserver.com/docs/
  - type: GettingStarted
    url: https://caddyserver.com/docs/getting-started
  - type: GitHubRepository
    url: https://github.com/caddyserver/caddy
  - type: Download
    url: https://caddyserver.com/download
common:
- type: AgenticAccess
  url: agentic-access/caddy-agentic-access.yml
- type: DomainSecurity
  url: security/caddy-domain-security.yml
- type: Website
  url: https://caddyserver.com/
- type: Documentation
  url: https://caddyserver.com/docs/
- type: GitHubOrganization
  url: https://github.com/caddyserver
- type: Community Forum
  url: https://caddy.community/
- type: Download
  url: https://caddyserver.com/download
- type: Sponsors
  url: https://github.com/sponsors/mholt
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com