Connect Your Node

When you use the public mempool.bitcoin-austria.at API, their servers see your IP address and every address and transaction you query. This creates a log linking your network identity to your Bitcoin activity.

By pointing am-i.exposed at your own node, API requests never leave your local network.

This is the #1 reason connections fail. Mempool's nginx config does not include CORS headers by default. Without them, your browser silently blocks every API response - even if the network connection is working perfectly.

Add these lines to your mempool nginx config, inside the existing location /api/ { } block:

# Add these lines inside your existing location /api/ { } block
add_header 'Access-Control-Allow-Origin' '*' always;
add_header 'Access-Control-Allow-Methods' 'GET, OPTIONS' always;
if ($request_method = 'OPTIONS') {
  return 204;
}

After editing, reload nginx:

nginx -s reload

Where to find the nginx config depends on your platform - see the platform-specific sections below.

This site is served over HTTPS. Browsers block HTTP requests from HTTPS pages (called mixed content) unless the target is localhost. An SSH tunnel forwards your node's mempool port to localhost on your machine, bypassing this restriction.

ssh -L 3006:localhost:3006 user@your-node-ip

http://localhost:3006/api

If you prefer using the am-i.exposed website instead of the Umbrel app, you can point it at your Umbrel's mempool instance. The mempool app listens on port 3006 via Umbrel's app_proxy container.

ssh umbrel@umbrel.local
docker exec -it mempool_web_1 sh
vi /etc/nginx/conf.d/nginx-mempool.conf

nginx -s reload

ssh -N -L 3006:localhost:3006 umbrel@umbrel.local

http://localhost:3006/api

Start9 serves mempool over HTTPS on a .local hostname with a self-signed certificate. There is no bare port to SSH tunnel to, so the approach is different from Umbrel.

https://<your-mempool-hostname>.local/api

If you run the official mempool/mempool Docker image or a bare-metal installation:

# Copy the default config out of the container
docker cp mempool_frontend_1:/etc/nginx/conf.d/nginx-mempool.conf ./nginx-mempool.conf

# Edit it to add CORS headers (see Step 1 above)

# Restart with the custom config mounted
docker run -v $(pwd)/nginx-mempool.conf:/etc/nginx/conf.d/nginx-mempool.conf ...

If you cannot or do not want to modify your node's nginx config, you can run a small reverse proxy on your desktop that adds CORS headers. This sits between your browser and the SSH tunnel.

:8090 {
  reverse_proxy localhost:3006
  header Access-Control-Allow-Origin *
  header Access-Control-Allow-Methods "GET, OPTIONS"
  @options method OPTIONS
  respond @options 204
}

http://localhost:8090/api

If both am-i.exposed and your mempool instance are accessed via .onion addresses in Tor Browser, there is no mixed-content blocking (both are HTTP) and Tor Browser relaxes CORS restrictions for .onion-to-.onion requests.

This requires a .onion mirror of am-i.exposed. If one is available, use Tor Browser to visit the .onion URL, then enter your mempool's .onion address in the settings.

You still need CORS headers on your mempool nginx if the .onion addresses differ (which they will, since they are separate hidden services).

1. 1.Click the gear icon in the header and enter your URL (e.g., http://localhost:3006/api)
2. 2.Click Apply - you should see a green checkmark and "Connected. Using custom endpoint."
3. 3.Run an analysis on any transaction or address - results should load normally
4. 4.The gear icon shows an orange dot when a custom endpoint is active