Cosign

aid: cosign
name: Cosign
kind: opensource
description: Cosign is the command-line client of the Sigstore project for signing, verifying, and storing container images,
  OCI artifacts, blobs, and in-toto attestations. Cosign supports keyless signing using OpenID Connect identity providers
  (Google, GitHub, Microsoft) by obtaining short-lived certificates from the Fulcio certificate authority and recording signing
  events in the Rekor transparency log. Signatures and attestations are stored alongside the signed artifact in any OCI-compliant
  registry, and cosign integrates with policy controllers, KMS providers, hardware tokens, and SBOM workflows for software
  supply chain security.
url: https://raw.githubusercontent.com/api-evangelist/cosign/refs/heads/main/apis.yml
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
type: Index
access: Public
position: Provider
tags:
- Apache 2.0
- Attestations
- CLI
- Code Signing
- Containers
- Fulcio
- Go
- Keyless
- OCI
- OIDC
- Open Source
- Rekor
- Sigstore
- Supply Chain
- Transparency Log
- Verification
created: '2026-03-26'
modified: '2026-04-28'
specificationVersion: '0.20'
apis:
- aid: cosign:cosign-cli
  name: Cosign CLI
  description: Cosign is a command-line tool for signing, verifying, and storing container images and OCI artifacts. It supports
    keyless signing, hardware-backed keys, KMS providers, in-toto and SLSA attestations, and transparency log inclusion. The
    CLI is the primary user interface and does not expose its own HTTP API.
  humanURL: https://docs.sigstore.dev/cosign/
  properties:
  - type: Documentation
    url: https://docs.sigstore.dev/cosign/
  - type: GettingStarted
    url: https://docs.sigstore.dev/quickstart/quickstart-cosign/
  - type: Installation
    url: https://docs.sigstore.dev/cosign/system_config/installation/
  - type: GitHubRepository
    url: https://github.com/sigstore/cosign
  - type: Reference
    url: https://docs.sigstore.dev/cosign/reference/cosign/
  tags:
  - CLI
  - Containers
  - Keyless
  - OCI
  - Signing
- aid: cosign:rekor-api
  name: Sigstore Rekor API (consumed)
  description: Rekor is the Sigstore transparency log that cosign writes to and reads from when recording and verifying signing
    events. The public Rekor service exposes a REST API at rekor.sigstore.dev with operations for creating log entries, retrieving
    entries by index or UUID, fetching log info and proofs, and searching the index.
  humanURL: https://docs.sigstore.dev/logging/overview/
  baseURL: https://rekor.sigstore.dev
  properties:
  - type: Documentation
    url: https://docs.sigstore.dev/logging/overview/
  - type: OpenAPI
    url: https://raw.githubusercontent.com/sigstore/rekor/main/openapi.yaml
  - type: GitHubRepository
    url: https://github.com/sigstore/rekor
  tags:
  - Rekor
  - REST
  - Sigstore
  - Transparency Log
- aid: cosign:fulcio-api
  name: Sigstore Fulcio API (consumed)
  description: Fulcio is the Sigstore certificate authority that issues short-lived X.509 code-signing certificates bound
    to OIDC identities. Cosign calls the Fulcio public CA at fulcio.sigstore.dev during keyless signing to obtain a certificate
    for a verified identity.
  humanURL: https://docs.sigstore.dev/certificate_authority/overview/
  baseURL: https://fulcio.sigstore.dev
  properties:
  - type: Documentation
    url: https://docs.sigstore.dev/certificate_authority/overview/
  - type: GitHubRepository
    url: https://github.com/sigstore/fulcio
  tags:
  - CA
  - Certificates
  - Fulcio
  - OIDC
  - Sigstore
common:
- type: LinkedIn
  url: https://www.linkedin.com/company/sigstore
- type: Website
  url: https://www.sigstore.dev/
- type: Documentation
  url: https://docs.sigstore.dev/cosign/
- type: GettingStarted
  url: https://docs.sigstore.dev/quickstart/quickstart-cosign/
- type: Installation
  url: https://docs.sigstore.dev/cosign/system_config/installation/
- type: GitHubOrganization
  url: https://github.com/sigstore
- type: GitHubRepository
  url: https://github.com/sigstore/cosign
- type: ReleaseNotes
  url: https://github.com/sigstore/cosign/releases
- type: Blog
  url: https://blog.sigstore.dev/
- type: Community
  url: https://docs.sigstore.dev/about/community/
- type: Slack
  url: https://sigstore.slack.com/
- type: License
  url: https://github.com/sigstore/cosign/blob/main/LICENSE
- type: Security
  url: https://github.com/sigstore/cosign/security
- type: RoadMap
  url: https://github.com/sigstore/cosign/blob/main/ROADMAP.md
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com