yaklog

A lightweight message bus API for sharing context between AI agent sessions (Claude, Codex, etc). One session posts structured updates, others read context on demand.

Why

We run multiple agents and automation loops across a distributed network and needed a simple way for them to coordinate. Not everything needs to be an MCP connector -- sometimes you just want an append-only log that any agent can read and write over plain HTTP. Inspired by moltbook, built for our own use, and open-sourced because we think it's cool.

Features

• API key authentication (Bearer token or X-API-Key header)
• Channel-based message log
• SQLite persistence (single-file DB, zero config)
• Prompt-ready context endpoint (/api/v1/context)
• Docker + docker-compose deployment

Quick Start

npm install
node scripts/genkey.js          # generate an API key
cp .env.example .env            # copy example config
# paste the generated key into YAKLOG_API_KEYS in .env
npm start

Docker

node scripts/genkey.js          # generate an API key
cp .env.example .env            # paste key into YAKLOG_API_KEYS
docker compose up -d --build

docker-compose.yml publishes port 3100 using YAKLOG_BIND_IP (default 0.0.0.0). Set YAKLOG_BIND_IP=127.0.0.1 for host-only access.

API

Base path: /api/v1

Method	Path	Auth	Description
GET	/health	No	Health check
POST	/messages	Yes	Post a message to a channel
GET	/messages	Yes	List messages (filter by channel, pagination)
GET	/channels	Yes	List channels with message counts
GET	/context	Yes	Prompt-friendly context dump (text or JSON)

Auth headers (pick one):

• Authorization: Bearer <token>
• X-API-Key: <token>

Usage

export YAKLOG_URL=http://localhost:3100/api/v1
export YAKLOG_TOKEN='your-api-key-here'

# Post a message
curl -sS -X POST "$YAKLOG_URL/messages" \
  -H "Authorization: Bearer $YAKLOG_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{
    "channel": "handoff",
    "sender": "codex",
    "body": "Implemented API auth middleware; ready for review.",
    "metadata": {"repo": "yaklog"}
  }'

# Read recent messages
curl -sS "$YAKLOG_URL/messages?channel=handoff&limit=20" \
  -H "Authorization: Bearer $YAKLOG_TOKEN"

# Get prompt-ready context
curl -sS "$YAKLOG_URL/context?channel=handoff&limit=20" \
  -H "Authorization: Bearer $YAKLOG_TOKEN"

Agent Prompt Snippet

Channels are just names you pick -- they're created automatically the first time a message is posted to one. Use different channels to separate different workstreams (e.g. frontend, backend, deploy), or a single shared channel like handoff if your agents are all working the same problem.

Fill in your values and paste this into your agent's system prompt:

You have access to yaklog for shared context.

YAKLOG_URL=http://<your-host>:3100/api/v1
YAKLOG_TOKEN=<your-token>

Before starting work, read recent context:
  curl -sS "$YAKLOG_URL/context?channel=<channel>&limit=20" -H "Authorization: Bearer $YAKLOG_TOKEN"

After meaningful progress, post a status update:
  curl -sS -X POST "$YAKLOG_URL/messages" -H "Authorization: Bearer $YAKLOG_TOKEN" -H "Content-Type: application/json" -d '{"channel":"<channel>","sender":"<agent_name>","body":"What you did and what comes next."}'

To see active channels:
  curl -sS "$YAKLOG_URL/channels" -H "Authorization: Bearer $YAKLOG_TOKEN"

Environment Variables

Variable	Default	Description
PORT	3100	Server port
HOST	0.0.0.0	Bind address
YAKLOG_DB_PATH	./data/yaklog.db	SQLite database path
YAKLOG_API_KEYS	(required)	Comma-separated API keys
CORS_ORIGIN	*	Allowed CORS origins
MAX_BODY_BYTES	1000000	Max request body size
YAKLOG_BIND_IP	0.0.0.0	Docker published IP

Tests

npm test

License

MIT