Hosting and remote connection

Start and host a service on device A, set up local port mappings on remote device B through Connect, and access the remote service via localhost.

Video demo

Scenario overview

Goal: start an HTTP service on device A, host it through a DevBridge tunnel, connect to the tunnel from device B, and access device A's service at http://localhost:8080 on device B.

Device	Role	Responsibility
Device A	Host	Runs the local service and hosts its ports with DevBridge.
Device B	Connect	Connects to the tunnel and sets up local port mappings to access it.

Both devices must have the DevBridge CLI installed and be logged in. If not, see Install the DevBridge CLI.

Step 1: Start the local service on device A

In terminal 1 on device A, start an HTTP service listening on port 8080:

python3 -m http.server 8080

Once started, this terminal keeps running; the service listens on 0.0.0.0:8080 by default. Keep this terminal open.

Verify the service works:

curl http://127.0.0.1:8080

If it returns a listing of the files in the current directory, the service is working.

Step 2: Start Host on device A

There are two ways to run Host, depending on whether you reuse an existing tunnel.

Option 1: Use a temporary tunnel

If you don't have a reusable tunnel, let Host automatically create a temporary tunnel and host port 8080:

devbridge host -p 8080

To set a description and expiration:

devbridge host -p 8080 -d "tunnel description" -e 8

• -p 8080: hosts local port 8080.
• -d: tunnel description, optional.
• -e: expiration in hours, optional, defaults to 72 hours.

After Host succeeds, it prints the tunnel ID and access URL, in the following format:

https://<tunnelId>-<port>.devbridge-s2.hwtunnel.com

Note the <tunnelId> here; device B needs it to connect.

The image above shows the actual output of devbridge host -p 8080: it automatically creates tunnel yf7oqwea, hosts port 8080, and prints the corresponding tunnel URL.

Temporary tunnel lifecycle

A tunnel created by devbridge host -p 8080 is retained after you stop Host — it isn't deleted automatically. Clean it up with devbridge delete <tunnelId> when you no longer need it.

Option 2: Use an existing tunnel

Before reusing an existing tunnel, confirm that it exists and that port 8080 is already configured.

1. List the valid tunnels in the current workspace:

   devbridge list

   Confirm the target tunnel ID is in the list.

2. View the tunnel's port configuration:

   devbridge port list <tunnelId>

   Confirm port 8080 already exists. If it doesn't, create it first:

   devbridge port create <tunnelId> -p 8080 --protocol http

3. Start Host to host all the ports of that tunnel:

   devbridge host <tunnelId>

   Host loads all the ports configured in the tunnel and begins forwarding; you don't need to specify -p again.

   

   The image above shows the actual output of devbridge host ghirszae: Host successfully hosts port 8080 and prints the tunnel URL; during the run it triggers an automatic reconnection and resumes forwarding after recovering.

Either way, Host keeps running in the foreground. Keep terminal 2 open; press Ctrl+C to stop hosting.

Step 3: Start Connect on device B

On device B, run the following command to connect to the tunnel:

devbridge connect <tunnelId>

Replace <tunnelId> with the tunnel ID that Host printed in step 2.

Connect reads the tunnel's port configuration, requests a Connect token, and sets up local port mappings. After the connection succeeds, port 8080 on device B maps to the service on device A.

Connect also keeps running in the foreground; keep the terminal open, and press Ctrl+C to stop the connection.

The image above shows the actual output of devbridge connect ghirszae: on success it shows Forwarding localhost:8080 -> tunnel port: 8080, meaning device B's local port 8080 is mapped to the tunnel port.

Step 4: Access the remote service on device B

Once the connection is established, access device A's service on device B through the local port:

curl http://127.0.0.1:8080

The HTML directory listing in the response is served by python3 -m http.server 8080 on device A, which confirms that device B has successfully reached device A's service through the local port mapping.

You can also open it in a browser:

http://localhost:8080

or use 127.0.0.1:

http://127.0.0.1:8080

Both are equivalent: they point to the local port mapping on device B, which DevBridge then forwards to the 8080 service on device A.

Quick reference

Step	Device	Terminal	Command	Description
1	Device A	Terminal 1	python3 -m http.server 8080	Start the local HTTP service.
2	Device A	Terminal 2	devbridge host -p 8080	Host with a temporary tunnel (Option 1).
2	Device A	Terminal 2	devbridge host <tunnelId>	Host with an existing tunnel (Option 2).
3	Device B	Terminal	devbridge connect <tunnelId>	Connect and set up local mappings.
4	Device B	Browser	http://localhost:8080	Access the remote service.

FAQ

Host exits immediately after starting

Confirm the local service in terminal 1 is still running. Host exits with an error when it detects that nothing is listening on the local port.

Connect succeeds but access returns empty or times out

Check these in order:

1. the Host process on device A is still running
2. device A's local service is still reachable: curl http://127.0.0.1:8080
3. port 8080 on device B isn't in use by another process
4. both sides use the same tunnel ID

Port already in use

If 8080 on device B is already in use by another process, Connect can't set up the mapping. Free the port first, or change the local service's listening port and run through the flow again.

Forgot the tunnel ID

Look it up on device A:

devbridge list

Both temporary and persistent tunnels appear in the valid tunnel list.

Cleanup

After verification, stop things in this order:

1. Device B: press Ctrl+C in the Connect terminal.
2. Device A: press Ctrl+C in the Host terminal.
3. Device A: press Ctrl+C in the service terminal to stop python3 -m http.server.

A temporary tunnel isn't deleted automatically after you stop Host. Clean it up once you're sure you no longer need it:

devbridge delete <tunnelId>

Related content

• Hosting and public access
• Host: expose local services
• Connect: connect to remote services
• What is DevBridge
• Troubleshoot Host and Connect issues