vLLM-Compatible

vLLM can serve open-source (and some custom) models via an OpenAI-compatible HTTP API. Fased connects through the vllm / openai-completions route. Use this same provider for vLLM, SGLang, TGI, LocalAI, FastChat, and similar OpenAI-compatible local servers. Use Custom Provider only when this shortcut does not match your endpoint. Fased can also auto-discover available models when you opt in with VLLM_API_KEY (any value works if your server does not enforce auth) and you do not define an explicit models.providers.vllm entry.

Quick start

Start the OpenAI-compatible server.

Your base URL should expose /v1 endpoints such as /v1/models and /v1/chat/completions. Local servers commonly run on:

http://127.0.0.1:8000/v1

Opt in (any value works if no auth is configured):

export VLLM_API_KEY="vllm-local"

Select a model (replace with one of your served model IDs):

{
  agents: {
    defaults: {
      model: { primary: "vllm/your-model-id" },
    },
  },
}

Model discovery (implicit provider)

When VLLM_API_KEY is set (or an auth profile exists) and you do not define models.providers.vllm, Fased will query:

GET http://127.0.0.1:8000/v1/models

…and convert the returned IDs into model entries. If you set models.providers.vllm explicitly, auto-discovery is skipped and you must define models manually.

Explicit configuration (manual models)

Use explicit config when:

the server runs on a different host/port.
You want to pin contextWindow/maxTokens values.
Your server requires a real API key (or you want to control headers).

{
  models: {
    providers: {
      vllm: {
        baseUrl: "http://127.0.0.1:8000/v1",
        apiKey: "${VLLM_API_KEY}",
        api: "openai-completions",
        request: { allowPrivateNetwork: true },
        models: [
          {
            id: "your-model-id",
            name: "Local Served Model",
            reasoning: false,
            input: ["text"],
            cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
            contextWindow: 128000,
            maxTokens: 8192,
          },
        ],
      },
    },
  },
}

request.allowPrivateNetwork: true is required for loopback, LAN, and private VPS endpoints. Public model providers should leave it unset.

Health And Capabilities

Agent > Models probes this provider when configured. The row can show reachable, auth ok, models discovered, and private network approved. Fased does not assume vision, tools, or reasoning support from a local model ID unless the configured model entry declares it.

Troubleshooting

Check the server is reachable:

curl http://127.0.0.1:8000/v1/models

If requests fail with auth errors, set a real VLLM_API_KEY that matches your server configuration, or configure the provider explicitly under models.providers.vllm.

Overview

Setup and routing

Common providers

Local and private

Additional providers

vLLM-compatible

vLLM-Compatible

Quick start

Model discovery (implicit provider)

Explicit configuration (manual models)

Health And Capabilities

Troubleshooting

​vLLM-Compatible

​Quick start

​Model discovery (implicit provider)

​Explicit configuration (manual models)

​Health And Capabilities

​Troubleshooting

vLLM-Compatible

Quick start

Model discovery (implicit provider)

Explicit configuration (manual models)

Health And Capabilities

Troubleshooting