openapi: 3.1.0
info:
  title: crates.io Sparse Config Index API
  description: 'The crates.io sparse index serves per-crate metadata files over HTTP rather than requiring a clone of the legacy crates.io-index Git repository. Cargo uses the sparse protocol by default since Rust 1.70 (June 2023). The index also publishes a config.json document at the root and supports HTTP cache validation via ETag and Last-Modified.

    '
  version: v1
  contact:
    name: crates.io Team
    email: help@crates.io
    url: https://crates.io
  license:
    name: Cargo Documentation (MIT/Apache-2.0)
    url: https://doc.rust-lang.org/cargo/reference/registry-index.html
servers:
- url: https://index.crates.io
  description: crates.io Sparse Index (sparse+https://index.crates.io/)
tags:
- name: Index
  description: Per-crate index metadata files served over HTTP
paths:
  /1/{crate}:
    get:
      summary: Get Index For One-Character Crate
      description: Returns the newline-delimited JSON index entries for a single-character crate name (e.g. /1/a).
      operationId: getIndexOneChar
      tags:
      - Index
      parameters:
      - name: crate
        in: path
        required: true
        schema:
          type: string
          minLength: 1
          maxLength: 1
      responses:
        '200':
          description: Newline-delimited JSON index entries.
          content:
            text/plain:
              schema:
                type: string
        '304':
          description: Not modified (ETag/If-None-Match match).
        '404':
          description: Crate not found.
  /2/{crate}:
    get:
      summary: Get Index For Two-Character Crate
      description: Returns the newline-delimited JSON index entries for a two-character crate name (e.g. /2/io).
      operationId: getIndexTwoChar
      tags:
      - Index
      parameters:
      - name: crate
        in: path
        required: true
        schema:
          type: string
          minLength: 2
          maxLength: 2
      responses:
        '200':
          description: Newline-delimited JSON index entries.
          content:
            text/plain:
              schema:
                type: string
        '304':
          description: Not modified.
        '404':
          description: Crate not found.
  /3/{first}/{crate}:
    get:
      summary: Get Index For Three-Character Crate
      description: Returns the newline-delimited JSON index entries for a three-character crate name. Path uses the first character as a directory (e.g. /3/r/rng).
      operationId: getIndexThreeChar
      tags:
      - Index
      parameters:
      - name: first
        in: path
        required: true
        schema:
          type: string
          minLength: 1
          maxLength: 1
      - name: crate
        in: path
        required: true
        schema:
          type: string
          minLength: 3
          maxLength: 3
      responses:
        '200':
          description: Newline-delimited JSON index entries.
          content:
            text/plain:
              schema:
                type: string
        '304':
          description: Not modified.
        '404':
          description: Crate not found.
  /{first_two}/{second_two}/{crate}:
    get:
      summary: Get Index For Four-Plus-Character Crate
      description: 'Returns the newline-delimited JSON index entries for a crate with four or more characters. Path uses the first two characters as the first directory and characters three and four as the second directory (e.g. /se/rd/serde for "serde", /to/ki/tokio for "tokio").

        '
      operationId: getIndexLong
      tags:
      - Index
      parameters:
      - name: first_two
        in: path
        required: true
        schema:
          type: string
          minLength: 2
          maxLength: 2
      - name: second_two
        in: path
        required: true
        schema:
          type: string
          minLength: 2
          maxLength: 2
      - name: crate
        in: path
        required: true
        schema:
          type: string
          minLength: 4
      responses:
        '200':
          description: Newline-delimited JSON index entries.
          content:
            text/plain:
              schema:
                type: string
              example: '{"name":"serde","vers":"1.0.0","deps":[],"cksum":"...","features":{},"yanked":false,"v":2}

                {"name":"serde","vers":"1.0.1","deps":[],"cksum":"...","features":{},"yanked":false,"v":2}

                '
        '304':
          description: Not modified.
        '404':
          description: Crate not found.