LibreChat

Before you connect

Use the custom Chat Completions endpoint for plain text chats. Prepaid accounts do not support agent tools, image/audio inputs, Assistants, or stored response lifecycle operations. Each user needs a ZRouter account, credit or supported BYOK, and an account API key.

Configure the custom endpoint

Merge this endpoints section into your existing librechat.yaml, retaining the configuration version required by your installed LibreChat release. Replace the URL and model ID:

endpoints:
  custom:
    - name: "ZRouter"
      apiKey: "user_provided"
      baseURL: "https://zrouter.si/v1"
      models:
        default: ["PROVIDER_INSTANCE/MODEL_ID"]
        fetch: false
      titleConvo: false
      modelDisplayLabel: "ZRouter"
      addParams:
        max_tokens: 256

Restart LibreChat according to its deployment instructions. Select ZRouter, provide your own ZRouter account key when prompted, and start a text chat. user_provided lets each person supply a separate credential; static server credentials instead charge the one ZRouter account that owns the key. See LibreChat's custom endpoint configuration.

The example disables model fetching and automatic titles to keep the initial setup predictable. Copy an exact model ID from ZRouter. Increase max_tokens only within the selected model and workspace limits.

Optional BYOK

After each user saves a provider key in their ZRouter dashboard, a BYOK-only custom endpoint can include:

      headers:
        X-ZRouter-BYOK: "true"

Place headers alongside baseURL, not inside models. Each user must have a saved key for the selected provider instance. This header changes all requests through that endpoint to BYOK; create a separately named gateway-funded endpoint if both modes are needed. Provider charges are separate from ZRouter routing fees.

Verify and troubleshoot

Send one short message and check the correct user's ZRouter usage and ledger. Do not use LibreChat display labels or forwarded user headers as evidence of billing isolation. The authenticated account key determines the billed account.

Keep tools and media features off for prepaid chat. Connection or parameter failures should be checked against shared troubleshooting and the selected provider's capabilities.