Bridge Sync

bridge-sync (hybrid)

Two Claude Code instances — local (laptop) and the VPS session — each hold a copy of the same app. This skill stops them clobbering each other: no edit lands on either side until both have compared state and agreed on the best version. Coordination uses Claude's built-in Remote Control (ListAgents + SendMessage) — no relay, no tunnel. Code moves over git (preferred) or rsync.

bridge-state.sh (in scripts/) prints a compact, comparable snapshot — use it instead of hand-gathering state.

Preconditions

1. ListAgents → find the VPS session (ask the user which if unclear). Confirm it is online (Remote Control sessions show offline when not connected). If offline, ask the user to connect it — don't reconcile blind. (Durable relay is the offline fallback; see claude-bridge README.)
2. Know the app dir on THIS host (ask once, e.g. local ~/dev/myapp, VPS ~/apps/myapp).

Coordination is turn-based

SendMessage hands control to the peer; you resume when it replies. Always name who to reply to (your ListAgents session name) in each message.

Shared journal (MCP) — the source of truth

The journal MCP server (tools: journal_read, journal_log, claim, release, claims_list) records what each side has done so neither acts on stale state. who is your identity (local or vps — check via ListAgents/context).

• Start of every turn: journal_read() to see what the peer did.
• Before editing a file or deploying: claim(who, resource). If it returns ok:false, the PEER holds it — coordinate over SendMessage, do NOT touch it.
• After every meaningful action: journal_log(who, action, target, status) (e.g. action=PUSH/DEPLOY/EDIT/VERIFY/DONE).
• When finished with a resource: release(who, resource). If the journal MCP isn't registered, fall back to announcing actions over SendMessage — but prefer the journal; it survives restarts and enforces locks.

The core rule

Read journal → claim → exchange state → discuss diff → agree → apply → verify → log/release. Never skip "agree", even for a one-liner — the peer may hold changes you can't see.

Workflow — INITIATOR (the side being edited, usually local)

1. Announce + request state. Snapshot yours: scripts/bridge-state.sh <app>. SendMessage({to: "<vps-session>"}):

   "bridge-sync : I intend . Run bridge-state.sh <your app path> and reply your snapshot. Don't edit yet. Reply to <my-name>."

2. (Turn ends.) On the VPS's snapshot, diff & classify vs yours:
   • git.head equal, both clean → in sync; apply your change, go to step 5.
   • equal but one side dirty → uncommitted work exists; surface whose/what.
   • git.head differ → diverged; find common ancestor from the commit lists.
   • no git → compare file hashes.
3. Discuss to converge (the "best version" step). SendMessage your reading + proposal; let the peer push back (hotfix to preserve? whose change wins per file?). Loop until you BOTH name the same target (a commit/branch or concrete file set). Get an explicit "agreed" — don't assume.
4. Apply on your side so your copy equals the agreed target; commit.
5. Propagate the bytes (git preferred): push agreed branch/sha; SendMessage the VPS: "pushed , git pull + test + restart, reply result." (No shared remote → send a git diff patch inline, or rsync via bridge-push.)
6. Verify both sides (tests, --version, health/restart); exchange results.
7. Close: both SendMessage "done, synced at , green." Report to user.

Workflow — RESPONDER (VPS, re-invoked by an incoming message)

1. On a state request: scripts/bridge-state.sh <your app> → reply the snapshot. Edit nothing yet.
2. Be honest in the discussion: uncommitted changes or a running hotfix? SAY SO — that's exactly what this step exists to catch. Object BEFORE applying if the plan would lose your work.
3. On the agreed apply message: git pull (or apply patch), run verification, reply result, then "done" when green.

Moving code (bytes, not chat)

1. Shared git remote — agree branch+sha; initiator pushes, peer pulls. Best.
2. Patch over SendMessage — small diffs only, text; peer git apply, then sha/test to confirm it applied clean.
3. rsync/tar over SSH — bridge-push.sh for large trees with no shared remote. Never assume a local path is visible to the peer — separate hosts.

Guardrails

• If state can't be compared (peer offline/silent past a reasonable wait, STATE_ERROR), STOP and tell the user. Don't one-sidedly deploy.
• If the VPS app is running/serving, treat its copy as production: converge toward not breaking it; restart only as an explicit agreed step.
• Keep messages tight and decision-oriented — reconciliation, not chat.

Example (MyApp, local initiates, git transport)

local: bridge-state.sh ~/dev/myapp         # head=a1b9 clean
local → SendMessage(vps): "bridge-sync MyApp: adding rate-limit to /scan.
        Run bridge-state.sh ~/apps/myapp, reply snapshot, don't edit. Reply to local."
vps   → SendMessage(local): "head=a1b9, dirty: server.js (uncommitted CORS hotfix), service active."
local → SendMessage(vps): "commit + push that hotfix to origin/main; I'll rebase rate-limit on top. Agreed?"
vps   → "agreed, pushed a1b9→c3d0."
local: (rebase, add rate-limit, push c3d0→e5f1)
local → SendMessage(vps): "git pull origin main (e5f1); npm test; restart myapp; reply result."
vps   → "tests green, service active on e5f1."
both  → SendMessage: "done, MyApp synced at e5f1, green."