# AGENTS.md — AI Agent Contributor Guide

This guide is for AI agents contributing to the Sprout codebase. It covers
agent-specific context and conventions. For general contributor info (setup,
code style, PR process, architecture), see [CONTRIBUTING.md](CONTRIBUTING.md).

---

## Ecosystem

Sprout spans five repos. This one (`block/sprout`) is the OSS source for the relay, desktop, mobile, and CLI. The others handle internal builds and deployment:

| Repo | Purpose |
|------|---------|
| [block/sprout](https://github.com/block/sprout) | OSS source — relay, desktop app, mobile app, CLI, agent harness |
| [squareup/sprout-releases](https://github.com/squareup/sprout-releases) | Buildkite pipeline producing Block-signed macOS + iOS builds with `-block` version suffix |
| [squareup/sprout-oss](https://github.com/squareup/sprout-oss) | CI pipeline building the relay Docker image and pushing to internal ECR |
| [squareup/block-coder-tf-stacks](https://github.com/squareup/block-coder-tf-stacks) | Terraform + ArgoCD deploying the relay to the staging Kubernetes cluster |
| [squareup/sprout-backend-blox](https://github.com/squareup/sprout-backend-blox) | Desktop backend provider script connecting Blox workstation agents to the relay |

```
block/sprout (source)
  ├─► sprout-releases    (desktop + mobile builds → Artifactory, GitHub, Mobile Releases)
  ├─► sprout-oss         (relay Docker image → ECR)
  │     └─► block-coder-tf-stacks  (Helm chart → ArgoCD → staging cluster)
  └─── sprout-backend-blox         (Blox compute provider for Desktop agent launch)
```

See [RELEASING.md](RELEASING.md) for the desktop release flow across `block/sprout` and `sprout-releases`.

---

## Repo Structure

```
crates/
  # Relay + core
  sprout-relay        # WebSocket relay server — main entry point; also hosts git + huddle audio
  sprout-core         # Core types, event verification, filter matching, kind registry
  sprout-db           # Postgres event store and data access layer
  sprout-auth         # Authentication and authorization
  sprout-pubsub       # Redis pub/sub fan-out, presence, typing indicators
  sprout-search       # Typesense-backed full-text search
  sprout-audit        # Hash-chain audit log
  sprout-media        # Blossom/S3 media storage
  # Agent surface
  sprout-mcp          # MCP server providing AI agent tools (being phased out in favor of the CLI)
  sprout-acp          # ACP harness bridging Sprout events to AI agents
  sprout-agent        # Minimal ACP-compliant agent (non-streaming, tool-calls-as-output)
  sprout-dev-mcp      # Developer MCP server — shell + file-edit tools
  sprout-persona      # Agent persona packs
  sprout-workflow     # YAML-as-code workflow engine (evalexpr conditions)
  # Clients + interop
  sprout-proxy        # Nostr client compatibility proxy (NIP-28)
  sprout-pair-relay   # Ephemeral sidecar relay for NIP-AB device pairing
  sprout-pairing-cli  # CLI for NIP-AB device pairing interop testing
  git-sign-nostr      # Sign git objects with a Nostr key
  git-credential-nostr # Git credential helper for Nostr-authed push/fetch
  # Tooling + shared
  sprout-cli          # Agent-first CLI
  sprout-sdk          # Typed Nostr event builders
  sprout-admin        # Operator CLI for relay administration
  sprout-test-client  # Integration test client and E2E test suite
  sprig               # All-in-one harness bundling ACP, agent, and dev MCP

desktop/              # Tauri 2 + React 19 desktop app
web/                  # Browser web client (repo browser, served by the relay)
mobile/               # Flutter mobile app
migrations/           # SQL migrations (auto-applied on relay startup)
scripts/              # Dev tooling
.env.example          # Config template — copy to .env before running
```

---

## Getting Started

```bash
. ./bin/activate-hermit   # activate hermit toolchain (Rust, Node, etc.)
cp .env.example .env      # configure local environment
just setup                # install deps, run migrations
just relay                # start relay at ws://localhost:3000
just ci                   # run before any PR
```

See CONTRIBUTING.md for full setup details and dependency requirements.

---

## Quality Gates

Run `just ci` before every PR — it runs `fmt` + `clippy` + desktop lint +
unit tests + builds. Clippy passing does not mean fmt passes; run both.

Run `just test` for integration tests if you touched `sprout-relay`,
`sprout-db`, or `sprout-auth` — these require a running Postgres and Redis.

**Pre-commit hooks** are installed automatically by `just setup` and auto-fix
formatting via `stage_fixed`. Pre-commit runs fix variants in parallel (Rust
fmt, Tauri Rust fmt, desktop biome fix, web biome fix, mobile dart format).
Auto-fixable issues are fixed and re-staged; unfixable lint issues block the
commit. **Pre-push hooks** run clippy (workspace + Tauri) and fast unit tests
in parallel (Rust, desktop JS, Tauri Rust, mobile Flutter) — no overlap with
pre-commit. Builds are CI-only. Run `just fix-all` to auto-fix all formatting
in one shot. Run `just ci` for the full local gate. Run `just hooks` to
re-install hooks after env changes.

Additional rules:
- No `unsafe` code
- Do not introduce new `unwrap()` or `expect()` in production paths — use `?` and proper error types
- New public API must have doc comments

---

## Key Patterns

**Dual API surface**: Sprout exposes both a REST API and a NIP-29 WebSocket
relay. Both paths converge on shared DB functions in `sprout-db`. When adding
a feature, implement the shared DB logic first, then wire up both surfaces.

**Prefer Nostr events over new REST endpoints**: For new feature work, model
the operation as a Nostr event (new kind in `sprout-core/src/kind.rs`, handler
in `sprout-relay`) rather than adding a new REST endpoint. REST is reserved
for things that genuinely need an HTTP-only surface: media upload/download
(Blossom), OAuth callbacks, health checks, and the existing read endpoints
that proxy DB queries. Two helpful endpoints already exist and rarely need
to be duplicated:

- `POST /events` — submit any signed event (same path the WebSocket uses).
- `POST /query` — Nostr REQ filters over HTTP. NIP-50 `search` filters
  are routed to `sprout-search` (Typesense-backed) automatically.
- `POST /count` — Nostr COUNT filters over HTTP.

If you find yourself reaching for a new REST endpoint, first check whether
an event kind would do the job — it usually will, and you get realtime
fan-out, NIP-29 scoping, and the existing auth pipeline for free.

Reference https://github.com/nostr-protocol/nips

**Event kinds**: All event kind integers are defined in
`sprout-core/src/kind.rs`. New features get new kind integers — add them here
first, then implement handling in the relay.

**Channel scoping**: Channels use `h` tags (NIP-29 group tag), not `e` tags.
Filters and queries must scope to `h` tags when operating within a channel.

**Agent-facing operations go in `sprout-cli`, not `sprout-mcp`**: `sprout-mcp`
is being phased out. New agent-facing features belong in `sprout-cli` — add a
subcommand there first, then wire the REST/WebSocket call in `client.rs`. Do
not add new tools to `sprout-mcp` unless specifically required for backward
compatibility. `sprout-dev-mcp` (shell + file tools for `sprout-agent`) is
separate and not being phased out.

**Workflow conditions**: `sprout-workflow` uses
[evalexpr](https://docs.rs/evalexpr) for condition evaluation. Keep expressions
simple and testable.

**Thread counters**: `reply_count` and `descendant_count` are materialized on
thread root events. Any code that inserts replies must update these counters —
check existing reply handlers for the pattern.

---

## Agent CLI (`sprout-cli`)

`sprout` is the agent-first CLI replacing `sprout-mcp`. Auth env vars
(`SPROUT_RELAY_URL`, `SPROUT_PRIVATE_KEY`, `SPROUT_AUTH_TAG`) are auto-injected
by the ACP harness into managed agent subprocesses.

All reads return sig-stripped JSON arrays; all writes return
`{event_id, accepted, message}`; creates add the entity ID. Exit codes:
0=ok, 1=input error, 2=network/relay, 3=auth, 4=other, 5=write conflict (NIP-33 LWW).

`--format compact` is a **global** flag — it goes before the subcommand:
`sprout --format compact channels list`, NOT `sprout channels list --format compact`.

See `crates/sprout-cli/TESTING.md` for the full live-testing runbook.

---

## Testing

```bash
just test-unit    # unit tests, no infrastructure needed
just test         # full integration suite (requires Postgres + Redis)
```

E2E tests live in `crates/sprout-test-client/tests/`:
- `e2e_relay.rs` — WebSocket relay protocol
- `e2e_rest_api.rs` — REST endpoint coverage
- `e2e_mcp.rs` — MCP tool surface
- `e2e_tokens.rs` — auth token flows
- `e2e_workflows.rs` — workflow engine
- `e2e_media.rs` — media upload/download (Blossom)
- `e2e_media_extended.rs` — extended media scenarios
- `e2e_nostr_interop.rs` — Nostr interop (NIP-50 search, NIP-10 threads, NIP-17 gift wraps)

Desktop E2E: `cd desktop && pnpm exec playwright test`

See [TESTING.md](TESTING.md) for the full multi-agent E2E guide.

---

## Common Gotchas

1. **Kind `39000` for channel metadata, not `41`** — kind 41 is NIP-01 (unused). All kinds defined in `sprout-core/src/kind.rs`.
2. **Relay queries must specify `kinds`** — omitting `kinds` triggers the p-gate (403). Always include explicit kind filters.
3. **`messages search` must include `--kinds`** — an open-ended search (no kinds) hits the relay p-gate and returns 403. Pass at least `--kinds 9,45001,45003` to scope the query.
4. **Worktrees: `cd` in the same command** — shell CWD doesn't persist between tool calls. Use `cd /path && cargo build` as one command.
5. **Desktop crate excluded from root workspace** — `cargo test` at repo root does NOT run desktop tests. Use `cargo test --manifest-path desktop/src-tauri/Cargo.toml` explicitly.
6. **Desktop Tauri fmt fails in worktrees and blocks commits** — the pre-commit hook runs `just desktop-tauri-fmt`, which fails in git worktrees because `cargo fmt` resolves workspace paths relative to the worktree root. Run `just desktop-tauri-fmt` from the main checkout to apply the fix, then re-stage and commit. CI is unaffected.

---

## Desktop App

The desktop app is Tauri 2 + React 19 + Vite + Tailwind CSS. Features are
organized under `desktop/src/features/`. Biome handles linting and formatting.

```bash
just desktop-dev   # web-only dev server (faster iteration)
just desktop-app   # full Tauri app with native shell
```

### Workspace Switching

The desktop app supports multiple workspaces (each backed by a different relay).
Switching workspaces does **not** reload the page — it uses React key-based
remounting. `<AppReady key={workspaceKey} />` in `App.tsx` forces the entire
workspace-scoped subtree to unmount and remount with fresh state.

**Module-level singletons must be explicitly reset.** React remounting only
clears React state (useState, useRef, context). Module-level variables (Maps,
class instances, cached promises) survive across remounts. Every workspace-scoped
singleton needs a reset function wired into `resetWorkspaceState()` in
`desktop/src/features/workspaces/useWorkspaceInit.ts`.

Current singletons that are reset on workspace switch:
- `relayClient.disconnect()` — WebSocket teardown + promise rejection
- `resetMediaCaches()` — proxy port and relay origin caches
- `clearSearchHitEventCache()` — search result event cache
- `clearAllDrafts()` — message draft cache

**If you add a new module-level cache, Map, or class instance that holds
workspace-scoped data, you must add its reset to `resetWorkspaceState()`.**
Failure to do so causes data from the old workspace to leak into the new one.

Key files:
- `desktop/src/app/App.tsx` — workspace key, init gate, remount boundary
- `desktop/src/features/workspaces/useWorkspaceInit.ts` — `resetWorkspaceState()`, applies config to Tauri backend
- `desktop/src/features/workspaces/useWorkspaces.tsx` — `WorkspacesProvider` context (shared state for App + AppShell)
- `desktop/src/main.tsx` — provider hierarchy (`QueryClientProvider` > `WorkspacesProvider` > `App`)

---

## Mobile App (Flutter)

The mobile app lives in `mobile/` — a Flutter app using Riverpod + Hooks.

### Architecture

- **State management:** Riverpod + `flutter_hooks` (`HookConsumerWidget`)
- **Theme:** Catppuccin Latte (light) / Macchiato (dark) — matches desktop
- **Features:** Isolated under `lib/features/`, shared code in `lib/shared/`
- **Nostr models:** `lib/shared/relay/nostr_models.dart` — event kinds must
  stay in sync with `desktop/src/shared/constants/kinds.ts`

### Rules

- **NEVER use `StatefulWidget`** — always use `HookConsumerWidget` or
  `ConsumerWidget` with `flutter_hooks` for local state.
- **NEVER run `flutter run`, `flutter build`, `flutter clean`, or
  `flutter upgrade`** — only `flutter test`, `flutter analyze`, and
  `dart format` are safe for agents to run.
- **Do NOT use `print()`** — use `debugPrint()` or structured logging.
- Prefer `context.colors` and `context.textTheme` (via theme extensions)
  over raw `Theme.of(context)` calls.
- Keep widgets small and composable.
- Feature modules must not import from other feature modules — only from
  `shared/`.
- Use `Grid` tokens for spacing, `Radii` for border radius.

### Quality Checks

```bash
cd mobile
dart format --output=none --set-exit-if-changed .
flutter analyze
flutter test
```

Or from repo root: `just mobile-fmt` (auto-fix), `just mobile-check` (lint + fmt check), `just mobile-test` (tests).

### Testing Conventions

- Prefer **widget tests** over unit tests for UI components — test the
  whole widget tree, not individual methods.
- Use `ProviderScope(overrides: [...])` to inject fake notifiers.
- Fake notifiers should extend the real notifier class and override `build()`.
- Use the `WidgetHelpers.testable()` wrapper for simple widget tests or
  build a custom `ProviderScope` + `MaterialApp` when you need specific overrides.

---

## See Also

- [CONTRIBUTING.md](CONTRIBUTING.md) — setup, code style, PR process, how to add event kinds / CLI subcommands / API endpoints
- [TESTING.md](TESTING.md) — multi-agent E2E test guide
- [ARCHITECTURE.md](ARCHITECTURE.md) — system design and component relationships
- [RELEASING.md](RELEASING.md) — release process: `just release`, auto-tag, internal builds
- [README.md](README.md) — project overview and quick start