Install and Use NVIDIA PAIR

Install and open PAIR

Install PAIR on each desktop system that will join the cluster. Download the appropriate package from the PAIR releases page.

Windows

1. Download the Windows installer that matches the system's architecture.
2. Run the installer and approve the operating-system and firewall prompts.
3. Open NVIDIA Personal AI Router from the Start menu.

Debian or Ubuntu

Open a terminal in the directory that contains the downloaded package, then run:

sudo apt install "./NVPAIR-Setup-VERSION-ARCH.deb"

Replace VERSION and ARCH with the values in the downloaded filename. Then open NVIDIA Personal AI Router from the desktop application menu.

macOS

1. Open the downloaded .dmg.
2. Drag NVIDIA Personal AI Router to Applications.
3. Open PAIR from Applications.

PAIR opens when the installation is complete.

Complete first-run setup

When you first open PAIR, it shows the engines that it can install. Ollama is selected by default when it is available for the platform.

1. Review the available engines.
2. Select the engines to install, or skip engines that you manage separately.
3. Finish setup and wait for the selected engine to report that it is running.

The first start can take longer while PAIR starts its background services. If Overview still shows Loading... after one or two minutes, open Settings → Service, then use the Troubleshooting tab.

You can return to engine settings by selecting a node in Overview. Use Settings → Cluster to pair systems at any time.

Pair systems

Start PAIR on each system. Confirm that the systems are on the same trusted local network.

1. On a system already in the cluster, select Add node in the top-right toolbar. You can also open Settings → Cluster and use Available nodes to add.
2. Select a discovered system. If PAIR does not find it, add the system by IP address.
3. PAIR shows a six-digit PIN and sends an invitation.
4. On the invited system, accept the Cluster invitation and enter the PIN.
5. Open Settings → Cluster and check that the peer appears under Connected nodes. You can also check the node list in Overview.
6. Repeat these steps from any cluster member to add more systems.

The peer appears as a connected node when pairing is complete.

Start an engine and add a model

Repeat these steps on every system that should serve the model:

1. Select the system in Overview to open its engine settings.
2. Install the engine if needed, then use its switch to start it.
3. Expand the engine and select Add model.
4. Download a model and wait for the download to finish.
5. Load the model if the engine requires a separate load step.

A system can serve a request when it is online, the engine is running, and the requested model is available there. To route requests across several systems, add the same model to each system that should serve it.

Copy the local endpoint

Applications connect to PAIR on the system where they run. They do not connect directly to an engine or to the system that will run the request.

1. Select Endpoints in PAIR's top toolbar.
2. In the API endpoints window, find the engine that you prepared.
3. Copy its http://127.0.0.1:<port> URL.

If the window says No engines are running, return to step 4 and start an engine. The endpoint appears when that engine is running on any system in the cluster, including a remote system.

Send a test request

Replace <PAIR_BASE_URL> with the endpoint from step 5. Replace <MODEL_NAME> with the exact model name from step 4.

Choose a request style

PAIR passes each request to the selected engine without rewriting it.

If you are unsure, use the OpenAI-style request. It works with either engine.

OpenAI-style request

curl <PAIR_BASE_URL>/v1/chat/completions \
  -H "Content-Type: application/json" \
  -d '{
    "model": "<MODEL_NAME>",
    "messages": [
      {
        "role": "user",
        "content": "Tell me a short story about a dog who learns to skateboard."
      }
    ]
  }'

Ollama-style request

Use this request only with an Ollama endpoint. The -N option shows the response as it streams.

curl -N <PAIR_BASE_URL>/api/chat \
  -H "Content-Type: application/json" \
  -d '{
    "model": "<MODEL_NAME>",
    "messages": [
      {
        "role": "user",
        "content": "Tell me a short story about a dog who learns to skateboard."
      }
    ]
  }'

Open Overview, select the Jobs filter, and read Ran on or Running on on the job card. A response and a job card show that PAIR routed the request.

Connect an application

Set the application's base URL to the endpoint from step 5. Select a model that you added in step 4.

PAIR accepts requests only from the system where it is running. The proxy uses plaintext HTTP on loopback. A network request to an address such as http://some-node:11434 returns 403.

Install PAIR on the system where you use the application. Join that system to the cluster, then use its local endpoint. The system does not need a GPU or an engine when another cluster system can serve the request.

PAIR does not provide a network-reachable inference endpoint. Configuring an engine to listen on the network is outside PAIR and creates security exposure that you must manage separately.

Port reference

PAIR's proxy uses the port that an engine normally uses. PAIR moves the engine to the next available port.

If OLLAMA_HOST names a different local loopback address, PAIR also serves that address when the port is free. PAIR does not use a remote or HTTPS OLLAMA_HOST value.

PAIR uses these ports to communicate between cluster systems:

The Windows installer adds the firewall rules. If a Linux firewall is restrictive, allow these ports between trusted cluster systems.

Next steps

Change a port

1. Open Overview and expand Engine settings on the local system's card.
2. Expand Ports for the engine.
3. Edit Proxy, Server, or both, then select Apply ports.

PAIR applies the change as one operation and restores the new values when it next starts. You can change ports only on the local system. Remote system cards show them as read-only. If you change a proxy port, update the application's base URL. Endpoints always shows the current URL.

If another application uses a port that PAIR does not manage, choose a different port in PAIR or stop the other application. Then restart the service from Settings → Service.

Use an engine's command line

PAIR-installed engines are normal installations, but their binaries are not in PATH and their server ports differ from the usual defaults.

Ollama locations:

Linux example:

ENGINE="$HOME/.config/Nvidia Corporation/Personal AI Router/engine-bin/ollama"
LD_LIBRARY_PATH="$ENGINE/lib/ollama" OLLAMA_HOST=127.0.0.1:11435 "$ENGINE/bin/ollama" list

Windows PowerShell example:

$ollama = "$env:LOCALAPPDATA\Nvidia Corporation\Personal AI Router\engine-bin\ollama\ollama.exe"
$env:OLLAMA_HOST = "127.0.0.1:11435"
& $ollama list

LM Studio installs to its standard location:

~/.lmstudio/bin/lms status

On Windows, the executable is %USERPROFILE%\.lmstudio\bin\lms.exe.

Set OLLAMA_HOST to the engine's Server value when you want to inspect the local engine. Otherwise, the CLI uses proxy port 11434 and returns the cluster-wide view. The proxy shows what the cluster can serve. The server port shows what is on that system.