crates.io
crates.io Web API

The crates.io Web API exposes the endpoints used by Cargo and the crates.io website to search the registry, fetch crate and version metadata, publish new versions, yank and unyank versions, and manage crate ownership. Hosted at https://crates.io/api/v1, it is the canonical implementation of the Cargo Registry Web API specification documented in the Cargo book.
crates.io Web API is one of 2 APIs that crates.io publishes on the APIs.io network, described by a machine-readable OpenAPI specification.
This API exposes 3 machine-runnable capabilities that can be deployed as REST, MCP, or Agent Skill surfaces via Naftiko and 2 JSON Schema definitions.
Tagged areas include Crates, Package Registry, Rust, Search, and Publishing. The published artifact set on APIs.io includes API documentation, an OpenAPI specification, a JSON-LD context, sample payloads, 3 Naftiko capability specs, and 2 JSON Schemas.
Documentation GitHub OpenAPI
OpenAPI Specification

openapi: 3.1.0
info:
  title: crates.io Web API
  description: >
    The crates.io Registry Web API exposes endpoints used by Cargo and the
    crates.io website for searching, publishing, yanking, and managing crate
    ownership. The API is hosted at https://crates.io under the /api/v1
    prefix and is the canonical implementation of the Cargo Registry Web API
    specification.
  version: v1
  contact:
    name: crates.io Team
    email: [email protected]
    url: https://crates.io
  license:
    name: Cargo Documentation (MIT/Apache-2.0)
    url: https://doc.rust-lang.org/cargo/reference/registry-web-api.html

servers:
  - url: https://crates.io
    description: crates.io Production

security:
  - ApiTokenAuth: []

tags:
  - name: Crates
    description: Search and manage Rust crates
  - name: Versions
    description: Yank and unyank crate versions
  - name: Owners
    description: List, add, and remove crate owners

paths:
  /api/v1/crates:
    get:
      summary: Search Crates
      description: >
        Search the crates.io registry for crates by query string. Returns a
        paginated list of matching crates with summary metadata. No
        authentication required.
      operationId: searchCrates
      tags:
        - Crates
      security: []
      parameters:
        - name: q
          in: query
          description: The search query string.
          required: false
          schema:
            type: string
        - name: per_page
          in: query
          description: Number of results per page (1-100, default 10).
          required: false
          schema:
            type: integer
            minimum: 1
            maximum: 100
            default: 10
        - name: page
          in: query
          description: Page number to return.
          required: false
          schema:
            type: integer
            minimum: 1
            default: 1
        - name: sort
          in: query
          description: Sort order (alpha, downloads, recent-downloads, recent-updates, new).
          required: false
          schema:
            type: string
            enum:
              - alpha
              - downloads
              - recent-downloads
              - recent-updates
              - new
      responses:
        '200':
          description: A paginated list of crates matching the query.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CrateSearchResponse'
        '400':
          $ref: '#/components/responses/Error'
  /api/v1/crates/new:
    put:
      summary: Publish A New Crate Version
      description: >
        Publish a new crate or crate version. The request body is a binary
        envelope containing a 32-bit little-endian length, the JSON metadata,
        a 32-bit little-endian length, and the .crate tarball.
      operationId: publishCrate
      tags:
        - Crates
      requestBody:
        required: true
        content:
          application/octet-stream:
            schema:
              type: string
              format: binary
              description: 32-bit LE metadata length, JSON metadata, 32-bit LE crate length, crate tarball.
      responses:
        '200':
          description: The crate was published successfully.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PublishResponse'
        '403':
          $ref: '#/components/responses/Error'
        '422':
          $ref: '#/components/responses/Error'
  /api/v1/crates/{crate}:
    get:
      summary: Get Crate Details
      description: Retrieve full metadata for a single crate including versions, owners, and keywords.
      operationId: getCrate
      tags:
        - Crates
      security: []
      parameters:
        - $ref: '#/components/parameters/CrateName'
      responses:
        '200':
          description: Crate detail document.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CrateDetailResponse'
        '404':
          $ref: '#/components/responses/Error'
  /api/v1/crates/{crate}/{version}:
    get:
      summary: Get Crate Version
      description: Retrieve metadata for a specific version of a crate.
      operationId: getCrateVersion
      tags:
        - Versions
      security: []
      parameters:
        - $ref: '#/components/parameters/CrateName'
        - $ref: '#/components/parameters/Version'
      responses:
        '200':
          description: Version metadata document.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/VersionDetailResponse'
        '404':
          $ref: '#/components/responses/Error'
  /api/v1/crates/{crate}/{version}/download:
    get:
      summary: Download Crate Tarball
      description: >
        Returns a redirect to the .crate tarball stored in the crates.io S3
        bucket. This is the canonical download URL used by Cargo.
      operationId: downloadCrate
      tags:
        - Versions
      security: []
      parameters:
        - $ref: '#/components/parameters/CrateName'
        - $ref: '#/components/parameters/Version'
      responses:
        '302':
          description: Redirect to the gzipped tar archive of the crate version.
          headers:
            Location:
              schema:
                type: string
                format: uri
        '404':
          $ref: '#/components/responses/Error'
  /api/v1/crates/{crate}/{version}/yank:
    delete:
      summary: Yank A Crate Version
      description: >
        Mark a specific crate version as yanked so that it is no longer
        selected as a fresh dependency. Existing Cargo.lock files continue
        to resolve against yanked versions.
      operationId: yankVersion
      tags:
        - Versions
      parameters:
        - $ref: '#/components/parameters/CrateName'
        - $ref: '#/components/parameters/Version'
      responses:
        '200':
          description: Yank successful.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/OkResponse'
        '403':
          $ref: '#/components/responses/Error'
  /api/v1/crates/{crate}/{version}/unyank:
    put:
      summary: Unyank A Crate Version
      description: Restore a previously yanked version of a crate.
      operationId: unyankVersion
      tags:
        - Versions
      parameters:
        - $ref: '#/components/parameters/CrateName'
        - $ref: '#/components/parameters/Version'
      responses:
        '200':
          description: Unyank successful.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/OkResponse'
        '403':
          $ref: '#/components/responses/Error'
  /api/v1/crates/{crate}/owners:
    get:
      summary: List Crate Owners
      description: Returns the list of users and teams that own a crate.
      operationId: listOwners
      tags:
        - Owners
      parameters:
        - $ref: '#/components/parameters/CrateName'
      responses:
        '200':
          description: Owner list document.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/OwnersResponse'
        '403':
          $ref: '#/components/responses/Error'
        '404':
          $ref: '#/components/responses/Error'
    put:
      summary: Add Crate Owner
      description: Invite a user or team as an owner of the crate.
      operationId: addOwner
      tags:
        - Owners
      parameters:
        - $ref: '#/components/parameters/CrateName'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/OwnersChange'
      responses:
        '200':
          description: Owner invitation issued.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/OkMessageResponse'
        '403':
          $ref: '#/components/responses/Error'
    delete:
      summary: Remove Crate Owner
      description: Remove a user or team from the owners of the crate.
      operationId: removeOwner
      tags:
        - Owners
      parameters:
        - $ref: '#/components/parameters/CrateName'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/OwnersChange'
      responses:
        '200':
          description: Owner removed.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/OkMessageResponse'
        '403':
          $ref: '#/components/responses/Error'

components:
  securitySchemes:
    ApiTokenAuth:
      type: apiKey
      in: header
      name: Authorization
      description: >
        A crates.io API token created at https://crates.io/settings/tokens. The
        raw token is sent in the Authorization header without a Bearer prefix.
  parameters:
    CrateName:
      name: crate
      in: path
      required: true
      description: The crate name (e.g. serde, tokio, rand).
      schema:
        type: string
    Version:
      name: version
      in: path
      required: true
      description: The semver version of the crate (e.g. 1.0.0).
      schema:
        type: string
  responses:
    Error:
      description: Error envelope returned by the crates.io API.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  schemas:
    CrateSearchResponse:
      type: object
      required:
        - crates
        - meta
      properties:
        crates:
          type: array
          items:
            $ref: '#/components/schemas/CrateSummary'
        meta:
          $ref: '#/components/schemas/SearchMeta'
    CrateSummary:
      type: object
      required:
        - name
        - max_version
      properties:
        id:
          type: string
        name:
          type: string
        description:
          type: string
        max_version:
          type: string
        max_stable_version:
          type: string
        newest_version:
          type: string
        downloads:
          type: integer
        recent_downloads:
          type: integer
        repository:
          type: string
        documentation:
          type: string
        homepage:
          type: string
        keywords:
          type: array
          items:
            type: string
        categories:
          type: array
          items:
            type: string
        created_at:
          type: string
          format: date-time
        updated_at:
          type: string
          format: date-time
    SearchMeta:
      type: object
      properties:
        total:
          type: integer
        next_page:
          type: string
          nullable: true
        prev_page:
          type: string
          nullable: true
    CrateDetailResponse:
      type: object
      required:
        - crate
      properties:
        crate:
          $ref: '#/components/schemas/CrateSummary'
        versions:
          type: array
          items:
            $ref: '#/components/schemas/Version'
        keywords:
          type: array
          items:
            $ref: '#/components/schemas/Keyword'
        categories:
          type: array
          items:
            $ref: '#/components/schemas/Category'
    Version:
      type: object
      required:
        - num
        - crate
      properties:
        id:
          type: integer
        crate:
          type: string
        num:
          type: string
        dl_path:
          type: string
        readme_path:
          type: string
        updated_at:
          type: string
          format: date-time
        created_at:
          type: string
          format: date-time
        downloads:
          type: integer
        features:
          type: object
          additionalProperties:
            type: array
            items:
              type: string
        yanked:
          type: boolean
        license:
          type: string
        rust_version:
          type: string
          nullable: true
        crate_size:
          type: integer
          nullable: true
    VersionDetailResponse:
      type: object
      required:
        - version
      properties:
        version:
          $ref: '#/components/schemas/Version'
    Keyword:
      type: object
      properties:
        id:
          type: string
        keyword:
          type: string
        created_at:
          type: string
          format: date-time
        crates_cnt:
          type: integer
    Category:
      type: object
      properties:
        id:
          type: string
        category:
          type: string
        slug:
          type: string
        description:
          type: string
        crates_cnt:
          type: integer
        created_at:
          type: string
          format: date-time
    OwnersResponse:
      type: object
      required:
        - users
      properties:
        users:
          type: array
          items:
            $ref: '#/components/schemas/Owner'
    Owner:
      type: object
      required:
        - id
        - login
      properties:
        id:
          type: integer
        login:
          type: string
        name:
          type: string
        kind:
          type: string
          enum:
            - user
            - team
        avatar:
          type: string
          format: uri
        url:
          type: string
          format: uri
    OwnersChange:
      type: object
      required:
        - users
      properties:
        users:
          type: array
          minItems: 1
          items:
            type: string
            description: A GitHub login (user) or a github:org:team identifier (team).
    OkResponse:
      type: object
      required:
        - ok
      properties:
        ok:
          type: boolean
    OkMessageResponse:
      type: object
      required:
        - ok
      properties:
        ok:
          type: boolean
        msg:
          type: string
    PublishResponse:
      type: object
      properties:
        warnings:
          type: object
          properties:
            invalid_categories:
              type: array
              items:
                type: string
            invalid_badges:
              type: array
              items:
                type: string
            other:
              type: array
              items:
                type: string
    ErrorResponse:
      type: object
      required:
        - errors
      properties:
        errors:
          type: array
          items:
            type: object
            properties:
              detail:
                type: string
crates.io Web API

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