Ghost Comments Shim

Lightweight Node.js service that syncs Bluesky replies to your Ghost blog's native comments system.

Overview

When you publish a Ghost post to Bluesky via the ATProto Bridge, people can reply to it on Bluesky. This shim syncs those replies back to Ghost as native comments, so they appear on your blog.

Architecture:

Bluesky → ATProto Bridge → This Shim → Ghost Database
                ↑                           ↓
         (central service)          (your Ghost server)

The shim runs on your Ghost server and receives comments from the central bridge.

Quick Start

1. Install the shim on your Ghost server

# Using npm (recommended)
npm install -g @ghost-atproto/comments-shim

# Or from source
git clone https://github.com/Cooperation-org/ghost-atproto.git
cd ghost-atproto/ghost-comments-shim
npm install && npm run build

2. Create a Bluesky member in Ghost

All synced comments will appear under this member:

1. Go to Ghost Admin → Members → New member
2. Fill in:
   • Email: [email protected]
   • Name: Bluesky
   • Note: Bridged comments from Bluesky/ATProto
   • Subscribed: No
3. Save and copy the member ID from the URL (24-character hex string)

3. Configure the shim

Create a .env file:

# Database (same credentials Ghost uses)
GHOST_DB_TYPE=mysql
GHOST_DB_CONNECTION=mysql://ghost:yourpassword@localhost:3306/ghost_production

# Shared secret (coordinate with the bridge admin - min 32 chars)
BRIDGE_SHARED_SECRET=your-super-secret-key-min-32-characters-long

# The member ID you copied in step 2
BLUESKY_MEMBER_ID=507f1f77bcf86cd799439011

# Port to listen on
PORT=3001

4. Run the shim

# Development
npm run dev

# Production
npm start

5. Configure the bridge

In the ATProto Bridge dashboard:

1. Go to Settings → Comment Sync
2. Enter your shim URL (e.g., http://your-ghost-server:3001)
3. Enter the same shared secret you configured in step 3

Configuration Reference

| Variable | Required | Description | |----------|----------|-------------| | GHOST_DB_TYPE | Yes | mysql or sqlite | | GHOST_DB_CONNECTION | Yes | Database connection string | | BRIDGE_SHARED_SECRET | Yes | Shared secret with bridge (32+ chars) | | BLUESKY_MEMBER_ID | Yes | Ghost member ID (24-char hex) | | PORT | No | Port to listen on (default: 3001) |

Finding your Ghost database credentials

For MySQL (most common):

cat /var/www/ghost/config.production.json | grep -A5 database

For SQLite:

# Usually at:
/var/www/ghost/content/data/ghost.db

Running as a Service

Systemd (recommended)

Create /etc/systemd/system/ghost-comments-shim.service:

[Unit]
Description=Ghost Bluesky Comments Shim
After=network.target ghost.service

[Service]
Type=simple
User=ghost
WorkingDirectory=/var/www/ghost-comments-shim
ExecStart=/usr/bin/node dist/index.js
Restart=on-failure
Environment=NODE_ENV=production
EnvironmentFile=/var/www/ghost-comments-shim/.env

[Install]
WantedBy=multi-user.target

Enable and start:

sudo systemctl enable ghost-comments-shim
sudo systemctl start ghost-comments-shim
sudo systemctl status ghost-comments-shim

Docker

FROM node:20-alpine
WORKDIR /app
COPY package*.json ./
RUN npm ci --only=production
COPY dist ./dist
CMD ["node", "dist/index.js"]

API Reference

POST /comments

Insert a Bluesky comment into Ghost.

Headers:

• Authorization: Bearer {BRIDGE_SHARED_SECRET}
• Content-Type: application/json

Request:

{
  "post_id": "507f1f77bcf86cd799439011",
  "bsky_handle": "alice.bsky.social",
  "bsky_profile_url": "https://bsky.app/profile/alice.bsky.social",
  "bsky_post_url": "https://bsky.app/profile/alice.bsky.social/post/3abc123",
  "comment_text": "This is my reply",
  "parent_comment_id": null,
  "created_at": "2025-01-15T12:00:00Z"
}

Response (201):

{
  "comment_id": "507f1f77bcf86cd799439012"
}

GET /health

Health check endpoint.

Response (200):

{
  "status": "ok",
  "version": "0.1.0"
}

Security

• The shim should only listen on localhost or be behind a firewall
• Use a strong BRIDGE_SHARED_SECRET (32+ characters, random)
• Consider rate limiting at the reverse proxy level
• All user-provided content is sanitized to prevent XSS

Testing

npm test

License

MIT