Agent HTTP

Agent HTTP

An HTTP API for Claude Code, built as a native MCP channel. Send messages to Claude Code over HTTP and get responses back — no terminal screen-scraping, no TUI parsing. Messages flow through Claude's native channel protocol.

The API is compatible with agentapi (POST /message, GET /messages, GET /status, GET /events), so it can serve as a drop-in replacement for agentapi in projects that only need Claude Code support.

How it works

agent-http is an MCP channel server that Claude Code spawns as a subprocess. It bridges HTTP and Claude Code's internal messaging system:

1. You send an HTTP request to the server
2. The server pushes it to Claude Code via the MCP channel protocol
3. Claude processes the message and calls the reply tool to send responses back
4. Responses are stored in conversation history and broadcast to SSE listeners

Unlike agentapi, which wraps any CLI agent by running it in a virtual terminal and parsing screen output, agent-http uses Claude Code's native channel system. Messages are exact — no terminal diffing, no TUI artifact stripping, no heuristics that break when the CLI updates.

Setup

Requires Bun and Claude Code v2.1.80+.

bun install

Usage

Start Claude Code with the channel loaded:

claude --dangerously-load-development-channels server:http-router

Claude Code reads .mcp.json, spawns the server, and the HTTP API starts on port 3284.

To use a custom port, update .mcp.json:

{
  "mcpServers": {
    "http-router": {
      "command": "bun",
      "args": ["./http.ts", "--port", "8080"]
    }
  }
}

API

Send a message

curl -X POST localhost:3284/message \
  -H "Content-Type: application/json" \
  -d '{"content": "Hello, Claude!", "type": "user"}'

Returns immediately with { "ok": true, "chat_id": "1" } once Claude starts processing. Also accepts plain text:

curl -X POST localhost:3284/message -d "What files are in this directory?"

Get conversation history

curl localhost:3284/messages

Returns an array of all messages:

[
  { "role": "user", "content": "Hello!", "timestamp": "2025-03-19T..." },
  { "role": "assistant", "content": "Hi there!", "timestamp": "2025-03-19T..." }
]

Check agent status

curl localhost:3284/status

Returns { "status": "stable" } when idle or { "status": "running" } when processing a message.

Stream events (SSE)

curl -N localhost:3284/events

Server-Sent Events stream that broadcasts message and status events in real-time:

event: status
data: {"status":"running"}

event: message
data: {"role":"assistant","content":"Hello!","timestamp":"2025-03-19T..."}

event: status
data: {"status":"stable"}

Chat UI

A simple web chat interface is available at:

http://localhost:3284/chat

Chat UI

A web chat interface is included for testing and demos:

http://localhost:3284/chat

It connects to the same API endpoints — messages sent from the chat UI show up in /messages and vice versa.

Health check

curl localhost:3284/health

Configuration

Priority: --port flag > CLAUDE_HTTP_PORT env > 3284 default.

Programmatic usage

Node.js / Bun

// Send a message
const res = await fetch("http://localhost:3284/message", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ content: "Explain this codebase" }),
});
const { chat_id } = await res.json();

// Poll for completion
const poll = async () => {
  while (true) {
    const status = await fetch("http://localhost:3284/status").then(r => r.json());
    if (status.status === "stable") break;
    await new Promise(r => setTimeout(r, 1000));
  }
  return fetch("http://localhost:3284/messages").then(r => r.json());
};

const messages = await poll();
console.log(messages.at(-1).content);

Python

import requests
import time

# Send a message
requests.post("http://localhost:3284/message", json={
    "content": "What does this project do?",
    "type": "user"
})

# Wait for response
while True:
    status = requests.get("http://localhost:3284/status").json()
    if status["status"] == "stable":
        break
    time.sleep(1)

# Get the response
messages = requests.get("http://localhost:3284/messages").json()
print(messages[-1]["content"])

SSE listener

const events = new EventSource("http://localhost:3284/events");

events.addEventListener("message", (e) => {
  const msg = JSON.parse(e.data);
  console.log(`[${msg.role}] ${msg.content}`);
});

events.addEventListener("status", (e) => {
  const { status } = JSON.parse(e.data);
  console.log(`Agent is ${status}`);
});