Cloud Custodian

Cloud Custodian is an open-source rules engine for cloud security, compliance, and cost-optimization governance now stewarded by Stacklet. Operators express policies as YAML files that select a cloud resource type, apply filters, and execute actions; the engine then runs those policies against AWS, Azure, and GCP via provider-specific plugins. Custodian does not expose a developer REST API of its own - integration is via the c7n CLI, the policy YAML schema, c7n-org for multi-account fan-out, and c7n-mailer for SQS-driven notifications.

Cloud Custodian is listed with 6 APIs on the APIs.io network, including C7n-Mailer, and 5 more. Tagged areas include Cloud Security, Compliance, Cost Optimization, Multi-Cloud, and Policy as Code.

The Cloud Custodian catalog on APIs.io includes 1 event-driven AsyncAPI specification, 1 JSON-LD context, and 2 Spectral governance rulesets.

Cloud Custodian’s developer surface includes documentation, getting-started guide, changelog, and 14 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

35.3/100 thin ▬ flat Agent 15/100 agent aware Front door AI 1/6 silent Heartbeat 100/100 alive self hosted · Apache-2.0 Full breakdown ↓
scored 2026-11-06 · rubric v0.27.0 · Show this score on your site →

AccessFreemium

6 APIs

Cloud Security Compliance Cost Optimization Multi-Cloud Policy as Code

Kin Score

Kin Score How this is scored →
scored 2026-11-06 · rubric v0.27.0

Composite quality — 35.3/100 · thin

Contract Quality 9.7 / 19

Developer Ergonomics 4.7 / 15

Access Clarity 1.2 / 15

Operational Transparency 3.6 / 10

Contract Governance 1.2 / 9

Discoverability 4.7 / 8

Regulatory Posture 1.6 / 15

Open Source Surface 6.0 / 10

Agent readiness — 15/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 0 / 10

Documented Reversibility 0 / 6

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 6 / 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

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Open Source Surface applies to this provider. This product is open source and we read its repository directly, so Open Source Surface carries 10 points of the composite. It is scored from what the repository actually publishes — a security policy, a contribution guide, a release history, a code of conduct — read live from the provider rather than inferred from our own catalog pointers. This facet adds; nothing was taken away to make room for it. An open-source project is not excused from the commercial facets, because exemption would strip it of the points it does earn. If we have the wrong repository, or this product is not open source, say so on your provider repo and we will drop the facet rather than have you publish against it.

Create-or-Update Ergonomics could not be measured. We hold no machine-readable contract for this provider to read, so there is nothing to measure a write surface against. Excluded rather than scored zero: never-measured and measured-empty are different facts. Publishing an OpenAPI is what makes this facet — and several others — scorable at all.

The six quality facets above are damped to 75 points between them, because both conditional facets apply and carry 25 points together. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship
Agentic Access Contract +10 pts — agentic_access artifact present (x-agentic-access), graded by author
Machine-Readable Auth +10 pts — a served openid-configuration/oauth-authorization-server carrying `issuer` (served), else the securitySchemes class in the provider OpenAPIs — bound (mutualTLS, DPoP, Signature) > negotiable (oauth2 authorizationCode/clientCredentials, openIdConnect) > bearer (http bearer, apiKey)
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented)
Stable Error Semantics +8 pts — OpenAPI $refs a shared error schema across 4xx/5xx responses (verified), else common[].type includes ErrorCatalog / ErrorCodes / DeclineCodes
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0

10 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Access Clarity scores 7.9 — up to +18.4 composite points
Developer Ergonomics scores 31.0 — up to +13.8 composite points
Contract Quality scores 51.5 — up to +12.1 composite points

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/cloud-custodian/apis.yml: open an issue on github.com/api-evangelist/cloud-custodian to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Markets this provider is in provisional

The Kin Score Market layer reads a provider inside its market: its position, and how deep its integrations go. Depth is only comparable within a position. Provisional and unweighted: not part of the Kin Score or agent readiness.

Market	Position	Depth	Registered MCP server	Declares compatibility
OpenSSF Best Practices Badge Holders	standard	40.9 (thin)	-	-

Registered MCP server and declares compatibility are report only — not weighted. Undeclared means we found nothing we can read, so there is no number: we never infer integrations.

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

AsyncAPI

measured — observed by APIs.io (published)

APIs 6

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

Cloud Custodian

Cloud Custodian provides rules-engine capabilities for managing cloud resources with security, compliance, and cost optimization policies.

Cloud Custodian AWS Provider

The Cloud Custodian AWS provider enables policy-as-code management of Amazon Web Services resources including EC2, S3, IAM, RDS, Lambda, and hundreds of other AWS service resour...

Cloud Custodian Azure Provider

The Cloud Custodian Azure provider enables policy-as-code management of Microsoft Azure resources including virtual machines, storage accounts, network security groups, and othe...

Cloud Custodian GCP Provider

The Cloud Custodian GCP provider enables policy-as-code management of Google Cloud Platform resources including Compute Engine instances, GCS buckets, Cloud SQL instances, and o...

Cloud Custodian C7n-Org

c7n-org is a Cloud Custodian tool for running policies across multiple cloud accounts, projects, or subscriptions in parallel. It uses an accounts configuration file with assume...

Cloud Custodian C7n-Mailer

c7n-mailer is a Cloud Custodian notification tool that subscribes to an SQS queue populated by policy actions and sends notifications via SES email, Slack messages, or integrati...

Cloud Custodian API pricing

Not yet checked against Cloud Custodian's own pricing page. Compiled by API Evangelist on 2026-05-04; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Free freemium	Free
Professional paid	Free
Enterprise enterprise	—

Plan details, limits and sources →

Rate limits

Free Tier Default: 10 requests per minute
Free Tier Monthly Quota: 1000 requests per month
Professional Tier Default: 100 requests per minute

Compiled by API Evangelist, not yet checked against Cloud Custodian's documentation. All 5 limits →

Pricing Plans 1

Published pricing tiers and plan structures.

Cloud Custodian Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Cloud Custodian Rate Limits

5 limits

RATE LIMITS

FinOps 1

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

Cloud Custodian Finops

FINOPS

Event Specifications 1

AsyncAPI definitions for this provider's event-driven and streaming APIs.

Cloud Custodian c7n-mailer Notification Events

The Cloud Custodian c7n-mailer AsyncAPI defines the event-driven notification interface used by the Cloud Custodian policy engine to deliver policy violation alerts. When a poli...

ASYNCAPI

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

Cloud Custodian Context

0 classes · 8 properties

JSON-LD

Spectral Rules 2

Spectral governance rulesets for linting and validating these APIs.

Cloud Custodian — asyncapi rules

3 rules · 1 errors 2 warnings

SPECTRAL

Cloud Custodian — jsonschema rules

6 rules · 5 warnings 1 info

SPECTRAL

JSON Schema 1

Standalone JSON Schema definitions for this provider's data models.

Cloud Custodian Policy File

2 properties

JSON SCHEMA

Security Posture 1

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

Cloud Custodian Domain Security

TLSv1.3

SECURITY

Resources

Get Started 1

Portal, sign-up, and the first successful call

GettingStarted

GettingStarted

Documentation 3

Reference material describing how the API behaves

Documentation

Documentation

JSONSchema

JSONSchema

AsyncAPI

AsyncAPI

Design & Contract 1

Pagination, idempotency, versioning, errors, and events

JSONLDContext

JSONLDContext

Build 2

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

GitHubRepository

GitHubRepository

Access & Security 2

Authentication, authorization, and security posture

SecurityPolicy

SecurityPolicy

DomainSecurity

DomainSecurity

Operate 4

Status, limits, changes, and where to get help

RateLimits

IssueTracker

Community

ChangeLog

Commercial 3

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

License

License

Company 1

The organization behind the API

Website

Website

Source (apis.yml)

aid: cloud-custodian
url: https://raw.githubusercontent.com/api-evangelist/cloud-custodian/refs/heads/main/apis.yml
name: Cloud Custodian
x-docs-platform: mkdocs
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-09-24
tags:
- Cloud Security
- Compliance
- Cost Optimization
- Multi-Cloud
- Policy as Code
type: Index
deliveryModel:
  model: self-hosted
  license: Apache-2.0
  open_source: true
  commercial: false
  callable_host: false
  label: Self-hosted open source · you run it yourself
  confidence: high
  source:
  - license
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: low
  source:
  - plans
  - security
  generated: '2026-11-06'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/cloud-custodian.png
access: Open Source
created: '2025-01-01'
modified: '2026-04-27'
position: Consuming
kind: opensource
description: Cloud Custodian is an open-source rules engine for cloud security, compliance, and cost-optimization governance
  now stewarded by Stacklet. Operators express policies as YAML files that select a cloud resource type, apply filters, and
  execute actions; the engine then runs those policies against AWS, Azure, and GCP via provider-specific plugins. Custodian
  does not expose a developer REST API of its own - integration is via the c7n CLI, the policy YAML schema, c7n-org for multi-account
  fan-out, and c7n-mailer for SQS-driven notifications.
apis:
- aid: cloud-custodian:cloud-custodian
  name: Cloud Custodian
  tags:
  - Cloud Security
  - Policy as Code
  humanURL: https://cloudcustodian.io/
  properties:
  - url: https://cloudcustodian.io/docs/
    type: Documentation
  - url: https://cloudcustodian.io/docs/quickstart/index.html
    type: GettingStarted
  - url: https://cloudcustodian.io/docs/overview/capabilities.html
    type: Reference
  - url: https://github.com/cloud-custodian/cloud-custodian
    type: GitHubRepository
  - type: JSONSchema
    url: json-schema/cloud-custodian-policy-schema.json
  description: Cloud Custodian provides rules-engine capabilities for managing cloud resources with security, compliance,
    and cost optimization policies.
- aid: cloud-custodian:cloud-custodian-aws
  name: Cloud Custodian AWS Provider
  description: The Cloud Custodian AWS provider enables policy-as-code management of Amazon Web Services resources including
    EC2, S3, IAM, RDS, Lambda, and hundreds of other AWS service resource types. Policies can be run in multiple execution
    modes including serverless Lambda functions, AWS Config rules, and scheduled CloudWatch Events.
  humanURL: https://cloudcustodian.io/docs/aws/gettingstarted.html
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - url: https://cloudcustodian.io/docs/aws/gettingstarted.html
    type: GettingStarted
  - url: https://cloudcustodian.io/docs/aws/resources/index.html
    type: Reference
  - url: https://cloudcustodian.io/docs/aws/examples/index.html
    type: Documentation
  tags:
  - Amazon Web Services
  - Cloud Security
  - Compliance
  - Policy as Code
  tags_raw:
  - AWS
  - Cloud Security
  - Compliance
  - Policy as Code
- aid: cloud-custodian:cloud-custodian-azure
  name: Cloud Custodian Azure Provider
  description: The Cloud Custodian Azure provider enables policy-as-code management of Microsoft Azure resources including
    virtual machines, storage accounts, network security groups, and other Azure services. Policies can enforce security requirements,
    tagging standards, and cost controls across Azure subscriptions.
  humanURL: https://cloudcustodian.io/docs/azure/gettingstarted.html
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - url: https://cloudcustodian.io/docs/azure/gettingstarted.html
    type: GettingStarted
  - url: https://cloudcustodian.io/docs/azure/policy/resources/index.html
    type: Reference
  tags:
  - Microsoft Azure
  - Cloud Security
  - Compliance
  - Policy as Code
  tags_raw:
  - Azure
  - Cloud Security
  - Compliance
  - Policy as Code
- aid: cloud-custodian:cloud-custodian-gcp
  name: Cloud Custodian GCP Provider
  description: The Cloud Custodian GCP provider enables policy-as-code management of Google Cloud Platform resources including
    Compute Engine instances, GCS buckets, Cloud SQL instances, and other GCP services. Policies can be used to enforce security,
    compliance, and cost governance standards across GCP projects.
  humanURL: https://cloudcustodian.io/docs/gcp/gettingstarted.html
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - url: https://cloudcustodian.io/docs/gcp/gettingstarted.html
    type: GettingStarted
  - url: https://cloudcustodian.io/docs/gcp/resources/index.html
    type: Reference
  tags:
  - Cloud Security
  - Compliance
  - GCP
  - Policy as Code
- aid: cloud-custodian:cloud-custodian-c7n-org
  name: Cloud Custodian C7n-Org
  description: c7n-org is a Cloud Custodian tool for running policies across multiple cloud accounts, projects, or subscriptions
    in parallel. It uses an accounts configuration file with assumed roles to orchestrate Custodian execution at scale across
    AWS Organizations, Azure subscriptions, or GCP projects.
  humanURL: https://cloudcustodian.io/docs/tools/c7n-org.html
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - url: https://cloudcustodian.io/docs/tools/c7n-org.html
    type: Documentation
  tags:
  - Cloud Security
  - Multi-Account
  - Orchestration
- aid: cloud-custodian:cloud-custodian-c7n-mailer
  name: Cloud Custodian C7n-Mailer
  description: c7n-mailer is a Cloud Custodian notification tool that subscribes to an SQS queue populated by policy actions
    and sends notifications via SES email, Slack messages, or integrations with DataDog and Splunk. It enables teams to alert
    resource owners when Custodian policies detect policy violations.
  humanURL: https://cloudcustodian.io/docs/tools/c7n-mailer.html
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  properties:
  - url: https://cloudcustodian.io/docs/tools/c7n-mailer.html
    type: Documentation
  - type: AsyncAPI
    url: asyncapi/cloud-custodian-mailer-asyncapi.yml
  tags:
  - Alerting
  - Email
  - Notification
  - Slack
  tags_raw:
  - Alerting
  - Email
  - Notifications
  - Slack
common:
- type: Plans
  url: plans/cloud-custodian-plans-pricing.yml
- type: RateLimits
  url: rate-limits/cloud-custodian-rate-limits.yml
- type: FinOps
  url: finops/cloud-custodian-finops.yml
- type: IssueTracker
  url: https://github.com/cloud-custodian/cloud-custodian/issues
- type: SecurityPolicy
  url: https://github.com/cloud-custodian/cloud-custodian/blob/main/SECURITY.md
- type: License
  name: Apache-2.0
  url: https://github.com/cloud-custodian/cloud-custodian/blob/main/LICENSE
- type: DomainSecurity
  url: security/cloud-custodian-domain-security.yml
- type: Website
  url: https://cloudcustodian.io/
- type: Documentation
  url: https://cloudcustodian.io/docs/
- type: GitHubOrganization
  url: https://github.com/cloud-custodian/cloud-custodian
- type: GettingStarted
  url: https://cloudcustodian.io/docs/quickstart/index.html
- type: Community
  url: https://cloudcustodian.io/community/
- type: GitHubRepository
  url: https://github.com/cloud-custodian/cloud-custodian
- type: ChangeLog
  url: https://github.com/cloud-custodian/cloud-custodian/releases
- type: JSONLDContext
  url: json-ld/cloud-custodian-context.jsonld
- type: JSONSchema
  url: json-schema/cloud-custodian-policy-schema.json
- type: AsyncAPI
  url: asyncapi/cloud-custodian-mailer-asyncapi.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
specificationVersion: '0.23'

Cloud Custodian API — frequently asked questions

Does Cloud Custodian have an API?

Yes. APIs.io lists 6 APIs from Cloud Custodian, including Cloud Custodian, Cloud Custodian AWS Provider and Cloud Custodian Azure Provider, and 3 more.

How much does the Cloud Custodian API cost?

APIs.io lists 3 pricing plans for Cloud Custodian, with each plan's price, limits and inclusions under Pricing on this page.

Is the Cloud Custodian API ready for AI agents?

Cloud Custodian has a Kin Score of 35.3 out of 100 (thin) and an Agent Readiness score of 14.7 (agent-aware), scored by API Evangelist on 2026-11-06.

Work with this as data

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