Cowork on 3P — How to Run Any LLM in Claude Cowork and Claude Code

Summary

Anthropic quietly shipped third-party inference for Claude Desktop — you can now run Cowork and Code against OpenRouter, Bedrock, Vertex, Foundry, or a local model proxy, with the same skill/plugin/MCP harness. This is enterprise-first but individuals on Max plans get full access. Strategically, Anthropic is locking in the harness (skills, plugins, sub-agents, MCP), not the model layer. Our read: this is less a feature drop and more a strategic declaration — model portability is the bait, and the tooling ecosystem is the lock-in.

Key Points

▸ 1. OpenRouter Works as a Claude Desktop Backend — No Proxy Required

What: Menu → Developer → Configure Third-Party Inference → Gateway base URL: https://openrouter.ai/api, auth scheme: x-api-key. Free models available (e.g. tencent/hy3-preview:free). Confirmed by OpenRouter CEO. Why it matters: This is the exact setup path for the queued "Claude Desktop Model Swap" guide, with confirmed working auth parameters and a free entry point. Apply to:

•vybecoding (guide): The queued guide "Claude Desktop Model Swap — How to Use OpenRouter, Foundry, or Local Models" now has confirmed, verbatim config values. Write it.

•vybeclaw (sprint): The current Sprint (Story 1) is evaluating OpenRouter routing. Note that agent-flow-routing.json already routes opencode labels to openrouter/qwen/qwen3-6b-plus:free — the evaluation should compare this OpenCode-proxied OpenRouter path vs direct API.

2. Brave Search MCP = Free Web Search Replacement for OpenRouter Setups

What: OpenRouter doesn't support Anthropic's native web_search tool. The documented workaround: add @modelcontextprotocol/server-brave-search as an MCP + set disabledBuiltinTools to suppress the conflicting built-in. 2,000 free requests/month, $3/1K after. Why it matters: vybeclaw currently uses gemini-cli for research/search routing specifically because Gemini has Google Search grounding. Brave MCP could serve as a lighter-weight search layer for tasks that don't need Gemini's depth. Apply to:

•vybeclaw: If the OpenRouter spike (current sprint) recommends adoption, add Brave Search MCP as the search tool for OpenRouter-routed tasks. The disabledBuiltinTools pattern is also useful documentation for any Claude Code config work.

•vybecoding (guide): Include the Brave MCP config block in the Claude Desktop Model Swap guide as the search section — it's a real gap users will hit.

3. Skills and Plugins Import via GitHub Zip Repos

What: Three official repos:

•Skills: github.com/anthropics/skills (docx, pdf, pptx, xlsx, skill-creator)

•Knowledge-work plugins: github.com/anthropics/knowledge-work-plugins (marketing, product-management, legal, finance)

•Code tab plugins: github.com/anthropics/claude-plugins-official

Import pattern: download repo as zip → extract → re-zip individual folders → upload via Customize UI.

Why it matters: Direct source for official plugin/skill reference material. Apply to:

•vybecoding (guide): Include the zip-download import steps + repo links in the guide. These are often undiscovered.

•vybeclaw: The skill-creator skill from the official skills repo may be useful as reference for VybeClaw's own skill scaffolding. Check if the skill-creator pattern maps to /make-skill.

4. Cowork on 3P is Enterprise Admin Infrastructure in Disguise

What: The config panel includes: per-user token caps, MCP allowlist, OpenTelemetry collector endpoint, block auto-updates, remove built-in tools. These controls don't matter to solo users — they're fleet management primitives. Why it matters: Anthropic's strategic move is clear: Claude Desktop becomes the managed agent platform harness. The model is interchangeable. The skills/plugins/MCP ecosystem is the moat. Worth noting: the OpenTelemetry endpoint is a tell — individual users don't need telemetry collectors, but IT departments require them before they'll greenlight any agent deployment at scale. Apply to:

•vybecoding (guide + strategic framing): The guide should call this out explicitly — "Anthropic is selling the harness, not the model." This is the differentiated angle vs. a plain setup tutorial.

•vybecoding (): The OpenTelemetry endpoint pattern in Cowork's admin config mirrors what vybecoding's agent control plane already does. No implementation change needed — but it validates the architecture.

5. Connectors Require Anthropic Infrastructure — MCP is the Fallback

What: When running on 3P inference, Anthropic's built-in Connectors (Gmail, Calendar, etc.) show as "Unavailable". MCP servers are local and still work. This is not a bug. Why it matters: Any content positioning Claude Desktop + OpenRouter for productivity workflows must route users to MCP alternatives, not Connectors. Apply to:

•vybecoding (guide): Explicitly flag this in a "What Doesn't Work" section. Users who relied on Connectors will be confused. Recommend MCP alternatives (Brave Search, Atlassian MCP example from the article).

6. Wiki Node Update: OpenRouter Now Has Cowork-on-3P Details

What: research/wiki/openrouter.md in vybeclaw mentions "pluggable backend for Claude Desktop" but predates the specific Cowork-on-3P feature details. Apply to:

•vybeclaw: Update research/wiki/openrouter.md to add: exact auth scheme (x-api-key), Gateway base URL format, free model availability, and the Connectors-unavailable limitation. Add source link to this article.

Action Items (Prioritized)

In my experience, the Connectors limitation (section 5) will be the first thing enterprise evaluators hit — it's worth surfacing it early in any guide or demo rather than letting users discover it mid-setup.

Source: productcompass.pm