Is it possible to use Headroom with the Claude desktop app (Claude.app)?

[gaaaork]

Question

I'm currently using Headroom as a permanent proxy (port 8788) for the claude CLI, which works great. I'm wondering whether it's also possible to route the Claude desktop app (Claude.app on macOS) through Headroom.

What I understand so far

• The claude CLI uses the Anthropic API (api.anthropic.com) and respects ANTHROPIC_BASE_URL → Headroom intercepts and compresses successfully.
• Claude.app appears to connect to the claude.ai web interface rather than the raw Anthropic API, which seems to make it incompatible with Headroom's proxy layer.

Questions

1. Does Claude.app actually use the Anthropic API under the hood, or exclusively the claude.ai web interface?
2. If it uses the API, would setting ANTHROPIC_BASE_URL=http://127.0.0.1:8788 (e.g. via launchctl setenv) be enough to route it through Headroom?
3. Is there any other mechanism (e.g. system proxy settings, network-level interception) that could make this work?

Context

• macOS, Headroom v0.22.4
• Running as a permanent launchd daemon (KeepAlive)
• Auth is handled via Keychain / Claude.app session (no ~/.claude/.credentials.json)

Thanks for the great tool!

[EmilioEsposito]

@gaaaork I think this is more of a Claude Desktop quirk, but would be great if there was documented workaround. Claude Desktop supports 3rd party inference, but I think it hinders certain things (e.g. claude.ai connected MCPs, Claude in Chrome) you get from your subscription (in CLI this doesn't happen). Enable Dev tools via Help->Troubleshooting, then go to Developer->Configure Third Party Inference

I haven't tried this with headroom yet, if someone can get it to work without the downsides it would be great!

[j-ts]

Yes, you can use it through MCP or ask Claude to create a file to start a proxy server (I prefer to start it manually) and it will route requests from the app to Headroom first (start server->(re)open app). I firstly did it with codex app and then with Claude.

I recommend being straightforward with the prompt though and say that routing must only work when you start the server and do not hardcoded or change Claude's setting files.

[github-actions]

This issue has had no recent activity and is being marked stale. Please comment with new context if it is still relevant.

[bigbgh]

I also have this question. I found this reddit which also suggests the MCP approach.

Can we get this added to the official install and quickstart documentation? I think that would allow closing this issue.