LibreChat

LibreChat is a self-hosted, multi-model chat app. It connects to any OpenAI-compatible service through a custom endpoint in its librechat.yaml config, so the proxy slots in next to whatever else you run.

Before you start

Do the shared setup from How-to guides first: the proxy must be running and funded.

LibreChat runs in Docker by default, so — like Open WebUI — the container can't reach localhost:9376 on your host. Read the Docker networking note: point LibreChat at http://host.docker.internal:9376/v1 and bind the proxy off loopback (PROXY_SERVER_LISTEN=0.0.0.0:9376).

Connect it

Add a custom endpoint to librechat.yaml

Add ZeroSignal under endpoints.custom:

endpoints:
  custom:
    - name: 'ZeroSignal'
      apiKey: 'zerosignal'                       # any non-empty value; the proxy ignores it
      baseURL: 'http://host.docker.internal:9376/v1'   # localhost:9376/v1 if LibreChat runs natively
      models:
        default: ['qwen3-coder']                 # a starting model; used until the list loads
        fetch: true                              # pull the live catalog from /v1/models
      titleConvo: true
      titleModel: 'qwen3-coder'                  # a real model id from the catalog
      modelDisplayLabel: 'ZeroSignal'

fetch: true tells LibreChat to populate the model dropdown from the proxy's /v1/models. titleModel must be a concrete model id — it's what LibreChat uses to name conversations.

(Optional) Keep the key out of the file

The key is a throwaway, but if you'd rather not hardcode it, use an environment variable and set it in .env:

      apiKey: '${ZEROSIGNAL_KEY}'

# .env
ZEROSIGNAL_KEY=zerosignal

Restart LibreChat

For a Docker install, make sure librechat.yaml is mounted (via docker-compose.override.yml) and restart:

docker compose down && docker compose up -d

A native install just needs a restart. The ZeroSignal endpoint now appears in the model/endpoint switcher.

Start a chat

Pick ZeroSignal in the endpoint switcher, choose a model, and send a message. The first reply confirms the path works end to end.

Troubleshooting

Symptom	Fix
ZeroSignal endpoint doesn't appear	All three pieces must line up: the endpoints.custom block in librechat.yaml, the mounted config in Docker, and (if used) the .env key. Restart after editing.
Endpoint appears but every chat errors	The container can't reach the proxy. Use host.docker.internal in baseURL and bind the proxy to 0.0.0.0:9376. On Linux add --add-host=host.docker.internal:host-gateway.
Empty model list	fetch: true failed to reach /v1/models (same networking cause as above), or the proxy was down. The models.default list is the fallback.
wallet_unfunded / payment errors	zs-proxy fund — see Wallet & funding.

What's next

• Configuration — server.listen, spend caps, and the output ceiling.
• Custom endpoints in LibreChat's own docs — every field on the endpoint object.
• How-to guides — connect another app.