# Buildpack Specification

**Canonical:** https://apis.io/apis/buildpacks-io/buildpack-spec/  
**Provider:** buildpacks-io — https://apis.io/providers/buildpacks-io/  
**Documentation:** https://github.com/buildpacks/spec/blob/main/buildpack.md

Buildpack Specification is one of 8 APIs that [buildpacks-io](https://apis.io/providers/buildpacks-io/) publishes on the [APIs.io](https://apis.io/) network. This API exposes 4 JSON Schema definitions. Tagged areas include Cloud Native Buildpacks, Buildpack API, Specification, and CNCF. The published artifact set on APIs.io includes API documentation, a JSON-LD context, and 4 JSON Schemas.

The Buildpack API (currently 0.12) defines the contract between an individual buildpack and the lifecycle. It specifies the on-disk layout of a buildpack (buildpack.toml, bin/detect, bin/build), the build plan provides/requires graph, layer types (launch/build/cache), launch.toml and build.toml outputs, target declarations (os/arch/distros), SBOM emission, and the CNB_* environment variable contract.

## Machine-readable artifacts (8)

- **Documentation** — https://github.com/buildpacks/spec/blob/main/buildpack.md
- **Repository** — https://github.com/buildpacks/spec
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/buildpacks-io/refs/heads/main/json-schema/buildpacks-buildpack-toml-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/buildpacks-io/refs/heads/main/json-schema/buildpacks-build-plan-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/buildpacks-io/refs/heads/main/json-schema/buildpacks-launch-toml-schema.json
- **JSONStructure** — https://raw.githubusercontent.com/api-evangelist/buildpacks-io/refs/heads/main/json-structure/buildpacks-io-structure.json
- **JSONLD** — https://raw.githubusercontent.com/api-evangelist/buildpacks-io/refs/heads/main/json-ld/buildpacks-io-context.jsonld
- **APIsJSON** — https://raw.githubusercontent.com/api-evangelist/buildpacks-io/refs/heads/main/apis.yml

## Other buildpacks-io APIs (7)

- [Platform Specification](https://apis.io/apis/buildpacks-io/platform-spec/)
- [Distribution Specification](https://apis.io/apis/buildpacks-io/distribution-spec/)
- [Image Extension Specification](https://apis.io/apis/buildpacks-io/image-extension-spec/)
- [Project Descriptor (project.toml)](https://apis.io/apis/buildpacks-io/project-descriptor-spec/)
- [Service Bindings Extension](https://apis.io/apis/buildpacks-io/service-bindings-spec/)
- [buildpacks-io Buildpacks API](https://apis.io/apis/buildpacks-io/buildpacks-io-buildpacks-api/)
- [buildpacks-io Search API](https://apis.io/apis/buildpacks-io/buildpacks-io-search-api/)

## Tags

Cloud Native Buildpacks, Buildpack API, Specification, CNCF

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/buildpacks-io/buildpack-spec/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/buildpacks-io/.