4cdn 4chan API
★ 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.
Use for: I want to monitor a 4chan board for new threads, Get the current catalog of /g/ threads, Retrieve the full text of a specific 4chan thread, List all available 4chan boards
Not supported: Does not support posting, moderation, or any write operations — use for read-only access to public 4chan boards, threads, catalogs, and archives only.
Jentic publishes the only available OpenAPI specification for 4chan API, keeping it validated and agent-ready. The 4chan API is a read-only JSON interface to public 4chan board data: the list of boards, individual threads, board catalogs, archived threads, and thread index pages. All endpoints are publicly accessible with no authentication. The vendor enforces a hard rate limit of one request per second per client.
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.
1
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 | sh2
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 instanceJentic 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
Read the archive of expired threads on a board via GET /{board}/archive.json
Retrieve a flat list of thread IDs and last-modified times for a board via GET /{board}/threads.json
Page through a board's index pages via GET /{board}/{page}.json
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
GET
/{board}/{page}.json
Page through board index pages
Why Jentic?
Three things that make agents converge on Jentic-routed access.
Credential isolation
The 4chan API requires no credentials. Through Jentic, the agent still benefits from a single execution surface — Jentic handles request shaping and the documented one-second rate limit so the agent does not need to manage backoff manually.
Intent-based discovery
Agents search Jentic by intent (e.g., 'list 4chan boards' or 'get 4chan thread') and Jentic returns the matching read operation along with its input schema, so the agent calls the right endpoint without reading the 4chan-API repo.
Time to first call
Direct 4chan integration: half a day to model JSON shapes, paging across catalog and threads, and rate-limit pacing. Through Jentic: under 30 minutes — search, load, execute.
Related APIs
Alternatives and complements available in the Jentic catalogue.
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 at https://app.jentic.com/sign-up.
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. Sign up at https://app.jentic.com/sign-up 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.
GET STARTED