4cdn 4chan API

Name: 4chan API
Brand: 4chan API
Availability: InStock

★ Only Publicly Available OpenAPI DocumentSocial MediaSocial Listeningnone6 EndpointsREST

For Agents

Read public 4chan boards, threads, catalogs, archives, and thread indexes for monitoring, archiving, and research without authentication.

Install Jentic One Beta

Connect the 4chan API to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the 4chan API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.

Step 1: Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh

Step 2: Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with 4chan API.

List all public 4chan boards via GET /boards.json

Retrieve the full catalog of active threads on a board via GET /{board}/catalog.json

Fetch a specific thread with all its replies via GET /{board}/thread/{threadId}.json

GET STARTED

Start building with 4chan API

Explore with Jentic

View OpenAPI Document

Use Cases

Patterns agents use 4chan API for, with concrete tasks.

★ Brand and Topic Mention Monitoring

Continuously poll boards for mentions of a brand, product, or named entity. Use GET /{board}/catalog.json to fetch active threads and scan subject and com fields for keywords, then drill into matched threads via GET /{board}/thread/{threadId}.json. Respect the documented one-request-per-second cap to avoid being throttled.

Every 60 seconds, fetch /g/catalog.json, find threads whose subject or com contains the keyword 'Acme', and write each matching thread's ID and snippet to a database.

Research Dataset Construction

Build a research dataset of public 4chan posts on a topic by paging through boards and persisting full thread JSON. GET /{board}/threads.json returns thread IDs with last-modified times so a crawler can detect changes; GET /{board}/thread/{threadId}.json fetches the full conversation. Useful for academic and OSINT research within ethical and legal boundaries.

For board /pol/, fetch /pol/threads.json hourly, identify threads modified since the last run, and download each updated thread's full JSON to S3.

Archive Snapshot of Expired Threads

Capture threads that are about to fall off a board by polling GET /{board}/archive.json for archived thread IDs and downloading each via the thread endpoint. This produces a long-tail snapshot of conversation that the live catalog no longer surfaces.

Fetch /a/archive.json, take the diff against the previously seen archive list, and download the full thread JSON for each newly archived ID.

Agent-Driven Public Content Monitoring

Let an AI agent poll 4chan boards on a schedule and surface relevant threads through Jentic. The agent searches for the right read operation by intent, supplies the board name, and gets back parsed thread data. Because endpoints require no auth, Jentic still handles request shaping, paging, and the documented rate limit on the client's behalf.

Through Jentic, search 'list 4chan boards', load the GET /boards.json operation, then iterate boards and pull /catalog.json for the user-supplied watchlist.

Key Endpoints

6 endpoints — jentic publishes the only available openapi specification for 4chan api, keeping it validated and agent-ready.

METHOD

PATH

DESCRIPTION

GET

/boards.json

List all public 4chan boards

GET

/{board}/catalog.json

Get a board's active threads catalog

GET

/{board}/thread/{threadId}.json

Retrieve a specific thread

GET

/{board}/archive.json

List archived threads on a board

GET

/{board}/threads.json

Get a board's thread index

GET

/{board}/{page}.json

Page through board index pages

GET

/boards.json

List all public 4chan boards

GET

/{board}/catalog.json

Get a board's active threads catalog

GET

/{board}/thread/{threadId}.json

Retrieve a specific thread

GET

/{board}/archive.json

List archived threads on a board

GET

/{board}/threads.json

Get a board's thread index

Why Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

The 4chan API needs no credential, so there is nothing to store, and your own Jentic One instance still keeps request handling out of the agent's prompt, logs, and context.

Intent-based discovery

Agents search Jentic by intent such as 'list 4chan boards' or 'get the threads on a board', and Jentic returns the matching 4chan operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

Time to first call

FAQs

Specific to using 4chan API through Jentic.

Why is there no official OpenAPI spec for 4chan API?

4chan publishes a Markdown reference at github.com/4chan/4chan-API but no OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call 4chan API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

What authentication does the 4chan API use?

None - the API is read-only and publicly accessible. The 4chan documentation specifies a hard rate limit of no more than one request per second per client; clients must space requests accordingly to avoid being blocked.

How do I get the list of all 4chan boards?

Call GET /boards.json against https://a.4cdn.org. The response contains the full board list with metadata such as board name, title, and posting rules - useful as a discovery step before crawling specific boards.

What are the rate limits for the 4chan API?

The vendor documents a limit of no more than one request per second per client. Build crawlers with at least a 1.0-second delay between requests; aggressive polling will get the client IP throttled or blocked.

How do I monitor a 4chan board through Jentic?

Run pip install jentic, then search 'get 4chan board catalog', load the GET /{board}/catalog.json operation, supply the board parameter, and execute on a schedule. Run it through Jentic One, the self-hosted execution layer to receive an agent API key for execution.

Can I post or modify content via the 4chan API?

No. The API is read-only - it surfaces boards, threads, catalogs, and archives but does not expose endpoints for creating posts, replies, or moderation actions. Posting must happen through the website itself.

Can I limit what my agent is allowed to do with the 4chan API?

Yes. Because you run Jentic One yourself, your own rules decide which 4chan operations and inputs the agent may use, and the 4chan API is read-only so no write path exists to begin with. You pick the exact calls it can make, so the agent might be allowed only GET /boards.json and GET /{board}/catalog.json and nothing else. Since the board sits in the URL path, such as /{board}/catalog.json and /{board}/thread/{threadId}.json, a rule can pin the agent to reading a single board.