LibreChat

LibreChat supports multiple providers side by side and lets you define per-model presets — system prompts, temperature, and capabilities — which makes it a good fit for a multi-model catalog like CAPI's.

Prerequisites

• LibreChat running from source or Docker.
• A CAPI API key.

Configure

LibreChat reads a librechat.yaml file. Add a custom endpoint:

version: 1.2.8

endpoints:
  custom:
    - name: "CAPI"
      apiKey: "${CAPI_API_KEY}"
      baseURL: "https://capi.ai/api/v1"
      models:
        default:
          - gpt-5.6
          - claude-opus-5
          - gemini-3.1-pro
          - deepseek-v4-flash
        fetch: false
      titleConvo: true
      titleModel: "gpt-5-mini"
      modelDisplayLabel: "CAPI"

Set fetch: false and list models explicitly. Auto-discovery returns the entire catalog, which produces an unwieldy dropdown; a curated list is easier to use and cheaper to run.

Mount the file when using Docker:

docker run -d \
  -e CAPI_API_KEY="capi_sk_live_..." \
  -v ./librechat.yaml:/app/librechat.yaml \
  -p 3080:3080 \
  ghcr.io/danny-avila/librechat:latest

Model presets

Presets let each model carry its own defaults, so users do not have to know that claude-opus-5 wants a different temperature than deepseek-v4-flash:

      models:
        default:
          - gpt-5.6
          - claude-opus-5
        endpoints:
          - name: "claude-opus-5"
            label: "Opus 5 (careful)"
            preset:
              temperature: 0.2
              maxContextTokens: 180000
          - name: "gpt-5.6"
            label: "GPT-5.6 (fast)"
            preset:
              temperature: 0.7

Title generation

LibreChat names conversations automatically. Point titleModel at something cheap and fast — gpt-5-mini or deepseek-v4-flash — so naming does not dominate your spend.

Vision and files

Multimodal models accept image attachments without extra configuration. Enable file upload in librechat.yaml if you want documents passed to the model directly rather than through RAG.

Balances and assistants

LibreChat's built-in balance API expects an OpenAI-style /dashboard/billing route, which CAPI does not implement. Disable balance display and check spend in the CAPI dashboard instead:

interface:
  balance:
    enabled: false

Troubleshooting

Custom endpoint missing from the UI. The YAML failed validation. LibreChat logs the parse error on boot — check the container logs.

${CAPI_API_KEY} unresolved. The variable is read at process start. Restart after exporting it, or hardcode for a local-only instance.

Streaming cuts out. Confirm the endpoint is https; a proxy stripping chunked transfer breaks SSE.

Next steps

• LLM API quickstart
• Chatbox