# opencontainers/image-spec

OCI Image Format

Repository: https://github.com/opencontainers/image-spec
Canonical: https://ross.abutalabs.com/products/image-spec
Homepage: https://www.opencontainers.org/
Language: Go
License: Apache-2.0
License Family: permissive
Topics: oci, containers, docker
Last push: 2026-07-09T17:22:16+00:00

## Health v2 (maintenance only)
Score: 64/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 91, release rhythm 8, longevity 100
- inputs: {"age_days": 3816, "days_push": 55, "days_rel": 548, "gap_med": null, "n_releases_24m": 1}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4453, forks 885 (observed 2026-08-28T04:08:50.521349+00:00)

## What it is
The Open Container Initiative (OCI) Image Format Specification, defining the standard layout and metadata for container images including manifests, configurations, and filesystem layers. The repository also ships Go types, JSON Schema, and validation tooling for implementing the spec.

## Use cases
- build container images that conform to the OCI image format
- validate OCI image manifests and blobs in Go
- implement a container registry or image builder compatible with Docker
- parse and manipulate OCI image manifests and configs programmatically
- package non-container artifacts like Helm charts or Wasm modules as OCI artifacts
- understand the standard container image format used by Docker and Kubernetes

## When to choose
- you are building container tooling (builders, registries, runtimes) in Go and need spec-compliant types
- you need to validate or generate OCI image manifests, configs, or layers
- you want interoperability with Docker, Kubernetes, and other OCI-conformant tools

## When to avoid
- you need a tool to actually build or run containers rather than implement the format
- you work in a language other than Go and only need the written specification
- you need the registry push/pull API - that is the separate distribution-spec project

## Facets
- artifact type: library
- maturity: stable
- function: container-runtime, serialization, developer-tools, sdk
- domain: cloud-computing, developer-tools
- platform: go, cross-platform
- tags: oci, container-images, specification, image-format, docker, -schema, standards, containers, devops, linux

## Member repositories
- opencontainers/image-spec (main) score 64

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:50.521349+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:20:46.035106+00:00, confidence not recorded.
  - readme: https://github.com/opencontainers/image-spec (fetched 2026-08-28T04:08:50.521349+00:00, sha 5913269d29ff)
  - homepage: https://www.opencontainers.org/ (fetched 2026-08-29T09:07:43.772998+00:00, sha cede10152191)
  - site_page: https://opencontainers.org/about/overview (fetched 2026-08-29T09:07:43.782400+00:00, sha 4a3bc773c315)
  - site_page: https://opencontainers.org/about/tob (fetched 2026-08-29T09:07:43.784501+00:00, sha c919f71c4f62)
  - site_page: https://opencontainers.org/about/security-disclosure (fetched 2026-08-29T09:07:43.786477+00:00, sha e6b2016f31a1)
  - site_page: https://opencontainers.org/faq (fetched 2026-08-29T09:07:43.788249+00:00, sha bdc269126fc3)
  - site_page: https://opencontainers.org/posts/blog/2024-03-13-image-and-distribution-1-1 (fetched 2026-08-29T09:07:43.790475+00:00, sha a0490c1d9e9f)
- Data as of 2026-08-30T08:39:29.467469+00:00.