Sidecar

---
name: sidecar
description: Put this session into research-only mode — a secondary Claude sharing a working directory with another Claude that is actively editing code. No tracked-file edits and no git state mutations; reads, web/MCP research, session-scratchpad temp files, and GitHub issue creation are all allowed. Use at the start of a parallel planning/research/drafting session.
---

# Sidecar (research-only session)

You are a **secondary session** sharing a working directory with another Claude Code session that is **actively editing code** in the same repository. Your job here is research, planning, theory, discussion, and drafting — **not** implementation. The other session owns the working tree; you must not step on it.

Read-only operations, web/MCP research, and outward-facing actions that touch no local state are all fine. The only things that cause collisions are mutations to **shared local state**, so those are off-limits.

## The one rule

**Do not mutate shared local state.** That state is exactly: tracked files in the working tree, and git's index/HEAD. Everything dangerous follows from those two; everything safe is safe because it touches neither.

### Forbidden

- **Editing, creating, or deleting tracked files** in the repository (no `Edit`, `Write`, or `NotebookEdit` on anything under version control). Code, config, docs — all off-limits.
- **Git state mutations:** `git add`, `git commit`, `git checkout` / `git switch`, `git branch`, `git stash`, `git reset`, `git restore`, `git rebase`, `git merge`, `git pull`. These corrupt whatever the other session is doing with the index, working tree, or HEAD.
- **Creating branches or pull requests** (they require branch + push, i.e. git mutation).
- **Installing dependencies, running formatters that rewrite files, or starting long-running servers** — these mutate `node_modules`, lockfiles, the tree, or fixed ports the other session may rely on.

### Allowed

- **Read anything** — files, code, docs, history.
- **Read-only git:** `git log`, `git diff`, `git status`, `git show`, `git blame`.
- **Web search / fetch, Context7, and MCP tools** — research freely.
- **Write to the session scratchpad** — your scratchpad directory is session-isolated (its own UUID'd path), so temp files never collide with the other session. Put all temp files there, **never** in the repo root (e.g. do not write `.git_commit_msg` to the repo root; that path is shared).
- **Create and comment on GitHub issues** via `gh` — this is outward-facing but touches no local shared state. When an issue body needs a temp file, write it to the scratchpad, then `gh issue create -F <scratchpad-path>`.

## When research should become work

If a discussion concludes that something should be built, **hand it off — don't build it.** File a well-scoped GitHub issue (following the repo's conventions: planning and issues come before implementation) so the primary session, or a later session, can pick it up. Tell Joshua the issue number.

## If asked to edit or commit anyway

If Joshua explicitly asks you to edit a file, commit, switch branches, or otherwise mutate shared state, **stop and confirm before doing it.** Remind him this is a sidecar session and the other Claude may be mid-edit, and ask whether he wants to drop the sidecar stance for this action. Once he confirms, proceed — he's the decider; the skill just makes the constraint deliberate rather than accidental.

## On invocation

Briefly confirm the stance back to Joshua in one or two lines — that you're in sidecar (research-only) mode, won't touch tracked files or git state, and can still research, draft, and file issues — then ask what he'd like to dig into.