Concepts

AgentSync has two halves over one substrate — git and the filesystem.

The two pillars

The skill engine autonomously creates and maintains a repo's agent skill files so they never drift from how the repo actually works. It watches how people use agents in a repo and updates the skill files to match, continuously, with no human in the loop.

The coordination layer — the rest of this page — lets many agents work in one repo without colliding: real-time presence, claim arbitration, and conflict prediction.

Actor

The principal that holds claims and authors commits — an agent session, a human, or a human-plus-agent pairing. One identity model covers a single operator running a fleet of agents and a team whose members each run their own:

Actor = {
  actor_id      // stable id, unique per repo coordinator
  kind          // "agent" | "human" | "human+agent"
  agent_vendor? // claude-code | codex | cursor | aider | ... (informational only)
  session_id?   // ephemeral run id
  display       // "agent-12" | "Rachel" | "Rachel · Claude"
}

Task

A unit of work, registered under .agentsync/tasks/<id>.yaml with a status, a base branch, and a branch name derived from your configured pattern (agent/{task_id}-{slug} by default).

Claim

A declared, arbitrated intent to write a set of paths on a branch, with a lease. Claims are granted by the coordinator in a total order:

• INVARIANT-1 — no two actors ever simultaneously hold overlapping write-claims.
• INVARIANT-2 — no change that violates a live claim can land on a protected branch.

exclusive_paths (for example package.json or migration files) are hard-locked — only one actor at a time, no exceptions. shared_paths (for example docs/**) allow overlap with a warning instead of a denial.

Coordinator

The linearizable, per-repo arbiter that grants claims. Any host that implements the coordinator API is a valid AgentSync coordinator:

• Advisory mode — no coordinator configured. Claims are recorded locally but not arbitrated; useful for a zero-setup trial, but not deterministic.
• Reference coordinator — self-hosted on your own Cloudflare account, MIT licensed, free forever. Runs as a Cloudflare Worker with a per-repo Durable Object as the arbiter; the Durable Object's single-threaded execution makes claim-granting naturally linearizable.
• RemoteHost-hosted coordinator — the same contract, zero setup, plus a live dashboard, org policy, and multi-user shared environments.

Agent-agnostic by design

AgentSync treats every agent as an opaque, possibly-changing black box and binds only to the two layers no vendor controls: the filesystem and git. An agent that has never heard of AgentSync still cannot land a conflicting change, because the gate lives at the git layer, not inside the agent.