# Architecture

Gito starts as a modular monolith with separable process roles. The codebase can
run as one service at first, but its boundaries should allow separate server,
worker, and shell deployments later.

## Layers

### Control Plane

- Owns proto-socket and REST surfaces.
- Accepts user, automation, and provider callback requests.
- Applies auth, policy, and approval gates.
- Creates operations and exposes event streams.
- Does not execute Git commands directly.

### Core Domain

- Owns repository registry, workspace leases, operations, revision cursors,
  idempotency keys, audit records, and normalized events.
- Knows provider-neutral concepts such as `Repo`, `WorkspaceLease`,
  `GitOperation`, `RevisionEvent`, and `ChangeRequest`.
- Does not know GitHub, GitLab, Gitea, Plane, Jira, or IOP HTTP details.

### Worker

- Picks pending operations.
- Coordinates workspace leases.
- Calls agent-shell for filesystem and command execution.
- Records operation outcomes and emits events.
- Handles retry and backoff policy.

### Agent Shell

- Runs on a machine that owns local workspace access.
- Executes Git CLI and IOP CLI commands.
- Streams logs, handles cancellation, and enforces dirty-workspace guards.
- Connects outbound to the control plane where possible.

### Git Engine

- Platformless Git operation layer.
- Supports clone, fetch, pull, checkout, status, diff, commit, push, branch, tag,
  and revision scans.
- Must be testable against local bare repositories without GitHub, GitLab, or
  Gitea.

### Provider Adapters

- Own platform APIs and DTOs.
- Map Forgejo/Gitea PR, GitHub PR, and GitLab MR into provider-neutral
  `ChangeRequest` operations.
- Treat webhooks as wakeup signals. Final state must be verified through Git
  revision or provider read APIs.
- MVP priority is Forgejo push intake: provider webhooks enter through REST
  callbacks, then Gito emits normalized branch events for internal proto-socket
  consumers such as NomadCode.

## Transport

- proto-socket is the default internal runtime transport.
- REST is reserved for health/readiness, provider callbacks, smoke/curl, and
  simple bootstrap endpoints.
- gRPC is intentionally out of scope for the initial architecture.

## Event Policy

All external side effects should produce durable operation and event records in
PostgreSQL. Redis may be added later for fanout or stream acceleration, but it is
not the source of truth.