4chan

opencollection: 1.0.0
info:
  name: 4chan Read-Only JSON API
  version: '2026-05-28'
items:
- info:
    name: Boards
    type: folder
  items:
  - info:
      name: 4chan List All Boards
      type: http
    http:
      method: GET
      url: https://a.4cdn.org/boards.json
    docs: Returns the comprehensive list of all 4chan and 4channel boards and their major settings (page count, per-page thread
      count, bump/image limits, cooldowns, feature flags, etc.). This is the canonical bootstrap call for any client — every
      other endpoint requires a board directory name from this document.
- info:
    name: Threadlist
    type: folder
  items:
  - info:
      name: 4chan Get Board Threadlist
      type: http
    http:
      method: GET
      url: https://a.4cdn.org/:board/threads.json
      params:
      - name: board
        value: po
        type: path
        description: Board directory short name (e.g. `a`, `b`, `g`, `pol`, `po`, `v`). The full list of valid values is the
          `board` field on each entry in `/boards.json`.
    docs: Returns a compact list of every live thread on the given board grouped by index page. Each thread entry contains
      only the OP number (`no`), the last-modified UNIX timestamp, and the reply count. Use this endpoint to detect new and
      updated threads cheaply; fetch the full thread or catalog only when `last_modified` changes.
- info:
    name: Catalog
    type: folder
  items:
  - info:
      name: 4chan Get Board Catalog
      type: http
    http:
      method: GET
      url: https://a.4cdn.org/:board/catalog.json
      params:
      - name: board
        value: po
        type: path
        description: Board directory short name (e.g. `a`, `b`, `g`, `pol`, `po`, `v`). The full list of valid values is the
          `board` field on each entry in `/boards.json`.
    docs: 'Returns the full catalog snapshot for the given board: every OP with its attributes and a short list of preview
      replies, grouped by index page. This is the largest per-board document and mirrors the public catalog page at `boards.4channel.org/{board}/catalog`.'
- info:
    name: Archive
    type: folder
  items:
  - info:
      name: 4chan Get Board Archive
      type: http
    http:
      method: GET
      url: https://a.4cdn.org/:board/archive.json
      params:
      - name: board
        value: po
        type: path
        description: Board directory short name (e.g. `a`, `b`, `g`, `pol`, `po`, `v`). The full list of valid values is the
          `board` field on each entry in `/boards.json`.
    docs: Returns the list of archived (closed, read-only) thread OP numbers for the given board. Archived threads remain
      viewable until 4chan automatically deletes them. Not every board has archives enabled — boards without an archive return
      404.
- info:
    name: Indexes
    type: folder
  items:
  - info:
      name: 4chan Get Board Index Page
      type: http
    http:
      method: GET
      url: https://a.4cdn.org/:board/:page.json
      params:
      - name: board
        value: po
        type: path
        description: Board directory short name (e.g. `a`, `b`, `g`, `pol`, `po`, `v`). The full list of valid values is the
          `board` field on each entry in `/boards.json`.
      - name: page
        value: '3'
        type: path
        description: Index page number, starting at `1`. The maximum value is the `pages` field on the matching entry in `/boards.json`
          (commonly 10 or 15).
    docs: Returns a single index page for the given board. Each index page contains an array of threads, and each thread contains
      its OP plus a small number of preview replies. The maximum page number for a board comes from the `pages` field on the
      matching entry in `/boards.json`.
- info:
    name: Threads
    type: folder
  items:
  - info:
      name: 4chan Get Thread
      type: http
    http:
      method: GET
      url: https://a.4cdn.org/:board/thread/:thread.json
      params:
      - name: board
        value: po
        type: path
        description: Board directory short name (e.g. `a`, `b`, `g`, `pol`, `po`, `v`). The full list of valid values is the
          `board` field on each entry in `/boards.json`.
      - name: thread
        value: '570368'
        type: path
        description: The OP number of the thread to retrieve.
    docs: 'Returns the full document for a single thread on the given board: the OP post object followed by every reply. To
      poll a thread for new replies, send `If-Modified-Since` on subsequent requests and treat `304` as "no change"; the minimum
      polling interval per the 4chan API rules is 10 seconds, with longer intervals preferred.'
bundled: true