docs: document correct Tailscale Funnel setup

[Waishnav]

Follow-up to #147. The connection failure comes from mounting Tailscale Funnel specifically at /mcp: the mount prefix is removed before proxying, and DevSpace also exposes OAuth discovery/authorization and MCP App routes outside /mcp. Adding a Tailscale-specific root MCP alias would therefore address only one symptom.

Document the root-level Funnel setup (tailscale funnel --bg 7676) in ChatGPT setup and troubleshooting, and explicitly warn against --set-path=/mcp. This keeps DevSpace tunnel-agnostic while preserving the full public route surface unchanged.

Summary by CodeRabbit

• Documentation
  • Added troubleshooting guidance for Tailscale Funnel connections returning 404 errors.
  • Clarified that the entire local server should be exposed from the Funnel root rather than mounted only at /mcp.
  • Updated ChatGPT setup instructions to include the correct Tailscale Funnel configuration and public endpoint format.

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[coderabbitai]

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ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 35c2e2e and 5100bbe.

📒 Files selected for processing (2)

• docs/gotchas.md
• docs/setup.md

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📝 Walkthrough

Walkthrough

The documentation adds Tailscale Funnel instructions for proxying the complete DevSpace server from the root path. It explains that --set-path=/mcp can strip /mcp and prevent MCP and OAuth routes from resolving.

Changes

Tailscale Funnel documentation

Layer / File(s)	Summary
Funnel setup and troubleshooting guidance docs/setup.md, docs/gotchas.md	Adds root-path Funnel instructions and explains why mounting only /mcp can cause 404 responses and omit OAuth routes.

Estimated code review effort: 1 (Trivial) | ~3 minutes

Merge Risk: ⚪ Minimal · up to 5100b

This change documents the correct root-level Tailscale Funnel setup and warns against mounting only /mcp, helping users avoid broken OAuth and MCP routes. No actionable merge-blocking risk remains after normal checks and review.

Poem

A rabbit proxies from the root,
No hidden path can make routes moot.
/mcp stays clear,
OAuth paths appear,
And 404s hop out of pursuit.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: documenting the correct Tailscale Funnel setup for DevSpace.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0…
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Full details: Docstring Coverage

Explanation

No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 0 files. (2 skipped: 2 unsupported.)

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch docs/tailscale-funnel-root-proxy

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[greptile-apps]

Greptile Summary

This PR documents the correct root-level Tailscale Funnel configuration for exposing DevSpace to ChatGPT.

• Adds the root Funnel command to the ChatGPT setup guide.
• Warns that mounting Funnel at /mcp strips the prefix and prevents access to DevSpace’s complete MCP and OAuth route surface.
• Adds corresponding troubleshooting guidance for /mcp 404 responses.

Confidence Score: 5/5

The documentation-only PR appears safe to merge.

The documented port and root proxy configuration match DevSpace’s defaults and preserve access to the MCP endpoint and root-level OAuth and application routes.

Important Files Changed

Filename	Overview
docs/setup.md	Adds root-level Tailscale Funnel setup guidance consistent with DevSpace’s port and route layout.
docs/gotchas.md	Explains why mounting Funnel at /mcp causes failures and directs users to proxy the complete origin.

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart LR
  Client["ChatGPT / MCP client"] --> Funnel["Tailscale Funnel at origin root"]
  Funnel --> Server["DevSpace :7676"]
  Server --> MCP["/mcp"]
  Server --> OAuth["OAuth discovery and authorization routes"]
  Server --> Apps["/mcp-app-assets"]

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