Claude Desktop & Cowork

Connect Claude Desktop (Cowork on third-party inference) to the TrueFoundry AI Gateway.

Claude Desktop can run in Cowork on third-party (3P) mode: the app routes inference to a gateway that implements the Anthropic Messages API instead of signing in to claude.ai. The TrueFoundry AI Gateway is compatible with this mode.

For more details, see Anthropic’s Installation and setup, Configuration reference, Using an LLM gateway, and the Help Center article Install and configure Claude Cowork with third-party platforms.

Prerequisites

Before you configure Claude Desktop, ensure you have:

1. TrueFoundry account — Create a TrueFoundry account and follow Gateway quick start. You need your gateway base URL (see Gateway base URL) and a TrueFoundry API key.
2. Models on the gateway — Add the Claude models you plan to use via TrueFoundry (Anthropic direct, Bedrock, or Vertex). See Anthropic model integration. For Cowork, include Opus, Sonnet, and Haiku so primary chats and sub-agents can resolve cleanly (details below).
3. Claude Desktop — Install from claude.com/download. For manual setup, launch the app but do not sign in until you have opened the configuration window (Anthropic recommends staying on the login screen).

Enable Developer Mode

The third-party inference UI is behind Developer Mode.

macOS: Menu bar → Help → Troubleshooting → Enable Developer Mode.

Windows: Application menu (top-left on the login screen) → Help → Troubleshooting → Enable Developer Mode.

Open the configuration window

Developer → Configure third-party inference.

You should see a sidebar with sections such as Connection, Sandbox & workspace, Connectors & extensions, and others. Work through Connection first, then Identity & Models as needed.

Connection — point Claude Desktop at TrueFoundry

1. Under Connection, choose Gateway (Anthropic-compatible).
2. Set Gateway base URL to your TrueFoundry AI Gateway URL.
3. Set Gateway API key to your TrueFoundry API key.
4. Set Gateway auth scheme to bearer (sends Authorization: Bearer <key>). Use x-api-key only if your deployment expects that header instead.
5. Gateway extra headers (optional) — one Name: Value per line for tenant routing or metadata, for example X-TFY-METADATA: {"team":"platform"}.

Identity & Models

Per Anthropic’s configuration docs, the model list for gateway inference is optional: when you leave it empty, Cowork calls the gateway’s GET /v1/models endpoint and builds the picker from the response. The TrueFoundry Gateway exposes this endpoint, so you can rely on auto-discovery.

It is still recommended to set the model list explicitly. When you configure it, the picker shows exactly the models you list instead of everything /v1/models returns. That helps you:

• Pin Haiku — Cowork’s built-in Explore sub-agent is configured to use Haiku for fast, read-only work. User-dispatched sub-agents in Cowork have also been observed to route through Haiku (anthropics/claude-code#47488). If discovery returns no Haiku id or several ambiguous Haiku variants, sub-agent calls can fail or behave unpredictably. Listing your-account/claude-haiku-4-5 (or your org’s equivalent) removes that ambiguity.
• Shorten the picker when discovery is noisy — /v1/models may list many ids. An explicit list is optional but handy when you want Cowork users to see only the models you intend for this deployment.

Add each model as provider-account/model-id (same strings you use in the TrueFoundry playground). Example (replace tfy-ai-anthropic with your Anthropic provider account name in TrueFoundry):

[
  "tfy-ai-anthropic/claude-opus-4-6",
  "tfy-ai-anthropic/claude-sonnet-4-6",
  "tfy-ai-anthropic/claude-haiku-4-5"
]

The first entry is the default in the model picker.

Apply locally and relaunch

Click Apply locally. Claude Desktop writes the configuration and relaunches. On the sign-in screen you should see the option to start in Cowork on 3P using the profile you just built.

Verify the integration

1. Start a Cowork session and send a short test message.
2. In TrueFoundry, open AI Gateway → Analytics (see Analytics overview) and confirm requests appear for your API key and chosen model.
3. For configuration diagnostics, use Help → Troubleshooting → Copy Managed Configuration Report — it summarizes detected keys and whether gateway credentials validated (secrets redacted).

Code tab and Claude Code CLI

The Code tab inside Claude Desktop uses Claude Code on the host. Some Cowork settings do not yet mirror one-to-one into Code-tab sessions. For terminal or VS Code workflows with environment variables and settings.json, follow Claude Code and Claude Code Max.

References

• Cowork on 3P — Installation and setup
• Cowork on 3P — Configuration reference
• Cowork on 3P — Using an LLM gateway
• Install and configure Claude Cowork with third-party platforms