Tag-Team LLM Coding

Put Claude Code and GitHub Copilot in structured debate inside VS Code, so they converge on a root cause before any edit — breaking the single-agent "guess → patch → analyze → repeat" loop on complex codebases.

How it works

You invoke @tag-team <problem> in the Copilot Chat panel. The extension acts as a mediator:

1. Proposal round (parallel) — Claude (via the claude -p CLI, with file/terminal tools) and Copilot (via the VS Code Language Model API) each return a structured proposal: a committed root-cause hypothesis, a proposed change, confidence, and open questions. They cannot hand back a patch without first naming a root cause.
2. Cross-critique — each model is shown the other's proposal and must refute it with evidence or concede. This is the loop-breaker: it forces engagement with an outside view instead of re-patching its own guess.
3. Convergence / checkpoint — when both agree (or after turnCap rounds) the mediator pauses and shows you the agreed diagnosis. You approve.
4. Apply — on /apply, Claude (the only side with autonomous file tools) makes the edit. A design doc is saved to .tagteam/session.md.

Concern	Choice
Role split	Symmetric debate; only Claude edits files
UI	Copilot Chat participant (@tag-team)
Claude auth	claude -p CLI on your Pro/Max subscription (no API key)
Control	Selectable — checkpointed or auto-resolve (see Settings)

Prerequisites

• VS Code ≥ 1.95
• GitHub Copilot installed and signed in (provides the second model)
• Claude Code CLI installed and logged in. Run claude once in a terminal to log in. If claude is not on the PATH VS Code sees, set tagTeam.claudePath to its absolute path (e.g. ~/.claude/local/claude).

Develop / run

npm install
npm run package:vsix

Then press F5 ("Run Tag-Team Extension") to open an Extension Development Host.

Marketplace package

Run the packaging command below to produce the distributable VSIX:

npm run package:vsix

The generated file will be written to the project root as tag-team-llm-<version>.vsix.

Settings

Setting	Default	Purpose
tagTeam.claudePath	claude	Path to the Claude CLI
tagTeam.claudeModel	(blank)	Optional --model override
tagTeam.copilotFamily	gpt-4o	Copilot model family
tagTeam.turnCap	3	Max debate rounds before checkpoint
tagTeam.autoResolve	false	When true, Claude applies the change automatically once both models agree on a root cause. If they never agree, you still decide.
tagTeam.claudeTimeoutMs	180000	Per-turn Claude timeout

Per-invocation flag

Even if tagTeam.autoResolve is false, you can force auto-resolve for a single debate using the /auto-resolve slash command:

@tag-team /auto-resolve why does the login hang on refresh?

Type @tag-team / in Copilot Chat and the available commands will autocomplete. If the models agree on a root cause, Claude will apply the change immediately. If they never agree (even after turnCap rounds), you'll still get the tie-break prompt.

Limitations

• The Copilot model is text-only here; it shapes the plan but does not edit files.
• Copilot may not return strict JSON — parsing is tolerant; Claude is schema-enforced.
• Headless Claude turns add latency; keep turnCap low for fast iteration.