Warp/PLAN.md

# Warp — a Matrix homeserver and client suite in Go

Project plan. Warp is a from-scratch [Matrix](https://spec.matrix.org) homeserver
written in Go, taking architectural lessons from
[Dendrite](https://github.com/element-hq/dendrite) without copying its code,
plus a family of first-party clients (admin panel, web, desktop, mobile).

---

## 1. Goals and non-goals

**Goals**

- Spec-conformant homeserver: Client-Server API, Server-Server (federation) API,
  Application Service API, Push Gateway client side.
- **Federation is optional.** Warp must run as a fully isolated, private
  homeserver with federation switched off, and be switchable at runtime.
- Single binary, single process ("monolith"). Dendrite's polylith mode was
  deprecated for good reason — the internal component boundaries stay, the
  network hops go.
- Three storage drivers: **PostgreSQL** (production), **SQLite** (dev /
  single-user), **PocketBase** (all-in-one appliance deployments).
- Pass [Complement](https://github.com/matrix-org/complement) (the official
  integration test suite, itself written in Go).
- Federate with Synapse, Dendrite, Conduit/Conduwuit/Tuwunel when enabled.
- First-party clients: admin web panel, web client, desktop client, Android
  app (iOS later), all sharing as much code as possible.

**Non-goals (for now)**

- Identity server, SSO/OIDC provider (delegate to MAS later), VoIP/TURN
  provisioning, legacy Sytest.

---

## 2. Key decisions

| Decision | Choice | Why |
|---|---|---|
| Go version | 1.26, `net/http` with pattern routing (`GET /_matrix/client/v3/...`) | No router dependency needed since Go 1.22. |
| Event core (canonical JSON, hashing, ed25519 signing, auth rules, state resolution v2) | **Own implementation**, tested against `gomatrixserverlib` test vectors and Complement | This is the heart of a homeserver and the point of the project. Fallback: import `gomatrixserverlib` if it stalls the schedule. |
| Internal messaging | Go interfaces + channels, one process | Dendrite embeds NATS JetStream; we don't need durable internal queues until we do. Design the producer/consumer interfaces so NATS can be dropped in later. |
| Storage | `database/sql` + hand-written SQL behind a per-component `Storage` interface; drivers: `pgx` (Postgres), `modernc.org/sqlite` (pure Go SQLite), PocketBase (embedded `core.App`, see §4) | Same dual-backend model as Dendrite plus one; no ORM. |
| Migrations | Embedded SQL files, per component, `embed.FS` | Simple, reviewable. |
| Config | Single YAML file + env overrides; a small set of settings (federation on/off, registration on/off) also mutable at runtime via admin API and persisted in DB | |
| Logging / metrics / tracing | `log/slog`, Prometheus `/metrics`, OpenTelemetry (later) | |
| Room versions | Implement the latest stable room version first (the one `m.room.create` defaults to in the current spec), then backfill older versions as needed for federation | Old room versions matter only when joining old rooms elsewhere. |
| Sync | `/sync` v3 first; Simplified Sliding Sync (MSC4186) as a later phase | Element X and our own mobile app want sliding sync; classic clients require `/sync`. |
| Frontend stack (admin + web client) | Vue 3 + TypeScript + Vite + Pinia; **Tailwind CSS** with a hand-rolled component set in `apps/ui` (Headless UI / Radix Vue for accessible primitives: dialogs, menus, listboxes) | Same UI code runs in the browser and inside the Wails desktop shell; Tailwind keeps the bundle small and the design system ours. |
| Desktop shell | **Wails v3** (Go host + webview) reusing the Vue web client | Pure-Go UI toolkits (Fyne/Gio) would mean a second UI codebase. |
| Mobile | Flutter + `matrix_dart_sdk` (famedly) with vodozemac for E2EE | Mature SDK; same codebase later ships to iOS. |
| Client protocol/crypto in Go | `mautrix-go` (+ `goolm` pure-Go Olm/Megolm) for the desktop host and any Go-side tooling; `matrix-js-sdk` + `matrix-sdk-crypto-wasm` in the browser | Do not write our own client-side crypto. |

---

## 3. Federation switch

`federation.enabled` is a first-class mode, not an afterthought.

```yaml
federation:
  enabled: false          # default off for a new install
  allowlist: []           # if non-empty, only these server names may federate
  denylist: []
  allow_runtime_toggle: true
```

**When disabled:**

| Area | Behaviour |
|---|---|
| Routes | `/_matrix/federation/*`, `/_matrix/key/*`, `/.well-known/matrix/server` are not registered (404). |
| Outbound | Transaction queue, key fetcher, remote media fetch, remote `keys/query`, remote profile/directory lookups are not started. |
| Client API | `/join` with `server_name` for a room not known locally → `M_FORBIDDEN` with a clear message; inviting `@user:otherserver` → `M_FORBIDDEN`; `publicRooms?server=` → `M_FORBIDDEN`. |
| Room IDs / event IDs | Unchanged — still `!id:warp.example`. Rooms created offline federate normally if federation is later enabled. |
| Signing | Events are still signed with the server key; only publication/verification of *remote* keys is skipped. |

**Runtime toggle:** `PUT /_warp/admin/v1/federation {"enabled": true}` (and the
admin panel switch). Implemented as a `federation.Module` with `Start(ctx)` /
`Stop()`; the HTTP mux delegates federation routes through a gate that checks
the live flag, so no restart is required. The setting is persisted in the
`server_settings` table and overrides the YAML value on boot if
`allow_runtime_toggle` is true.

**Allowlist mode** is the middle ground for "federate only with my other
servers": all remote traffic is filtered by server name at the auth layer and in
the outbound queue.

---

## 4. Storage drivers

All components talk to storage through Go interfaces (e.g.
`roomserver.Database`, `userapi.Database`). Each driver implements them.

| Driver | Engine | Target use | Notes |
|---|---|---|---|
| `postgres` | PostgreSQL 15+ via `pgx` | Production, multi-user, large rooms | Primary; Complement runs against this. |
| `sqlite` | `modernc.org/sqlite` (no cgo), WAL mode | Dev, tests, single-user | Serialised writer; fine up to a few hundred users. |
| `pocketbase` | Embedded [PocketBase](https://pocketbase.io) (`core.App`) on its own SQLite file | "Appliance" deployments: one binary that also provides admin auth, file storage (local/S3) for media, and realtime for the admin panel | Records are stored via PocketBase collections; heavier than raw SQLite and its record model is a poor fit for the event DAG, so **the roomserver/syncapi tables bypass PocketBase's collection API and use its underlying `dbx` connection directly**. PocketBase adds value for `mediaapi` (its filesystem abstraction) and for admin-panel auth. Marked experimental until it passes the same test suite as `sqlite`. |

Rules:

- One SQL dialect per driver, kept in `internal/storage/{postgres,sqlite,pocketbase}`.
- Every storage test runs against all three drivers (`go test -tags=storage_all`).
- Migrations are per-driver; `warp migrate` runs them.

---

## 5. Server architecture

```
                 +--------------------------------------------------+
 clients ------> |  clientapi   (C-S REST handlers, auth, ratelimit) |
                 +--------------------------------------------------+
 other HS -----> |  federationapi  [gated by federation.enabled]     |
                 +-------------+-------------+----------------------+
                 |  userapi    |  roomserver |  syncapi             |
                 |  accounts   |  event DAG  |  read model / streams|
                 |  devices    |  auth rules |  /sync, /messages    |
                 |  tokens     |  state res  |  filters, tokens     |
                 |  push rules |  redactions |                      |
                 +-------------+-------------+----------------------+
                 |  keyserver  |  mediaapi   |  appservice          |
                 |  device keys|  upload/dl  |  registration, txns  |
                 |  OTKs, x-sig|  thumbnails |                      |
                 +-------------+-------------+----------------------+
                 |  adminapi (/_warp/admin/*) + embedded admin SPA   |
                 +--------------------------------------------------+
                 |  internal/matrix: event, canonicaljson, signing, |
                 |  roomversion, auth, stateres                     |
                 +--------------------------------------------------+
                 |  storage: postgres | sqlite | pocketbase         |
                 +--------------------------------------------------+
```

**Data-flow principle (borrowed from Dendrite):** the roomserver is the single
writer for room events. Every event — local or federated — goes in through the
roomserver, which authorises it, resolves state, persists it, and then emits an
"output event" that the syncapi, federationapi (outbound, if enabled),
appservice, and push consumers subscribe to. Nothing else writes room state.

---

## 6. Repository layout (monorepo)

```
Warp/
├── go.work                       Go workspace tying the Go modules together
├── server/                       Go module: the homeserver
│   ├── cmd/warp/                 serve, generate-keys, create-account, migrate
│   ├── internal/
│   │   ├── config/
│   │   ├── httputil/
│   │   ├── matrix/               canonicaljson, event, signing, roomversion, auth, stateres
│   │   ├── clientapi/  federationapi/  roomserver/  syncapi/  userapi/
│   │   ├── keyserver/  mediaapi/  appservice/  pushserver/  adminapi/
│   │   └── storage/{postgres,sqlite,pocketbase,migrations}/
│   ├── web/admin/                build output of apps/admin, embedded via embed.FS
│   └── test/{complement,vectors}/
├── apps/
│   ├── ui/                       shared Vue 3 component library + Matrix client store (Pinia)
│   ├── admin/                    admin web panel (Vue) — built into server/web/admin
│   ├── web/                      web client (Vue SPA) + Go host (`cmd/warp-web`)
│   ├── desktop/                  Wails v3 app: Go host (mautrix-go) + apps/web frontend
│   └── mobile/                   Flutter app: Android now, iOS later
├── docs/
├── Dockerfile
├── Makefile
└── warp.yaml.example
```

Frontend packages are managed with `pnpm` workspaces (`apps/ui`, `apps/admin`,
`apps/web`); Go modules with `go.work` (`server`, `apps/web`, `apps/desktop`).

---

## 7. Server phases

Each phase ends with something runnable and a Complement subset passing.

### Phase 0 — Bootstrap (1 week)

- `go mod init`, layout above, `Makefile` (build/test/lint/complement), `golangci-lint`, GitHub Actions CI.
- Config loading, `slog` logging, graceful shutdown, `/healthz`, `/metrics`.
- HTTP server skeleton with Matrix error envelope (`errcode`, `error`), CORS,
  `GET /_matrix/client/versions`, `/.well-known/matrix/client` (and `/server`
  only when federation is enabled).
- Storage interfaces + migrations runner; `sqlite` driver first, `postgres`
  second, `pocketbase` stub compiled but returning `ErrNotImplemented`.
- `warp generate-keys` (ed25519 signing key file).
- `server_settings` table and the runtime-settings service (federation flag,
  registration flag).

### Phase 1 — Accounts & sessions (1–2 weeks)

- **userapi**: users, passwords (argon2id), devices, access tokens,
  refresh tokens, account data, admin flag.
- C-S endpoints: `register` (UIA with `m.login.dummy` / registration token),
  `login` (`m.login.password`), `logout`, `logout/all`, `account/whoami`,
  `devices/*`, `profile/*`, `user/{id}/account_data/*`, `capabilities`.
- Auth middleware, per-endpoint rate limiting (`M_LIMIT_EXCEEDED`).
- `warp create-account [--admin]` CLI.
- **adminapi v1** skeleton: admin-only auth, `GET/PUT /federation`,
  `GET/PUT /registration`, `GET /users`, `POST /users`, `GET /stats`.
- Complement: `TestRegistration`, `TestLogin`, `TestDeviceManagement`.

### Phase 2 — Event core (2–3 weeks, the hard part)

Pure library code under `internal/matrix`, no HTTP, no DB.

- Canonical JSON, event/PDU model, hashing, redaction algorithm.
- ed25519 signing and verification, key IDs.
- Room version registry.
- Authorisation rules (full spec list).
- State resolution v2.

### Phase 3 — Rooms, local only (2–3 weeks)

- **roomserver** storage and input pipeline (validate → auth → resolve →
  persist → emit).
- C-S: `createRoom`, `join`, `leave`, `invite`, `kick`, `ban`,
  `send/{type}/{txnId}`, `state/*`, `redact`, `rooms/{id}/event/{id}`,
  `members`, `joined_members`, aliases, `publicRooms`.
- Federation-disabled behaviours from §3 enforced here (remote joins/invites
  rejected).
- adminapi: room list, room detail, purge room, force-leave.
- Complement: `TestRoomCreate`, `TestRoomState`, `TestMembership*`, `TestRedactions`.

### Phase 4 — Sync (2 weeks)

- **syncapi** read model, stream tokens, `GET /sync`, `/messages`,
  `/context`, filters, lazy-loading members.
- EDUs: typing, receipts, presence (config flag), `to_device`.
- Complement: `TestSync*`, `TestMessagesPagination`, `TestTyping`, `TestReceipts`.

→ **Milestone M1**: Element Web works against Warp with federation off.
   The admin panel and web client (§8) can now be developed against a real server.

### Phase 5 — Federation (3–4 weeks)

- `federation.Module` with `Start/Stop`, route gate, allow/deny lists.
- Server keys, discovery, `X-Matrix` auth, `/send`, joins/leaves/invites,
  `/state`, `/state_ids`, `/backfill`, `/get_missing_events`, queries.
- Outbound queue with backoff, blacklist, persistence.
- Complement federation tests.

→ **Milestone M2**: Warp joins `#matrix:matrix.org`; toggling federation off
   at runtime cleanly stops all remote traffic and back on resumes it.

### Phase 6 — Media (1 week)

- `mediaapi`, thumbnails, authenticated media, remote media cache (federation
  only). PocketBase driver uses PocketBase's filesystem abstraction (local/S3).

### Phase 7 — E2EE support (2 weeks)

- `keyserver`: device keys, OTKs, fallback keys, cross-signing, device list
  tracking (local always; federated only when enabled), key backup,
  `sendToDevice`.

### Phase 8 — Push & notifications (1 week)

- Push rules, pushers, notification counts, push gateway client. Needed by the
  mobile app.

### Phase 9 — Application services & admin completion (1–2 weeks)

- AS registration, namespaces, transactions, masquerading.
- adminapi: full user management (deactivate, reset password, devices, admin
  flag), server notices, media quota, registration tokens, federation
  allow/deny list editing, audit log.

### Phase 10 — Hardening & ops

- Simplified Sliding Sync (MSC4186), spaces, threads, search.
- PocketBase driver to parity with `sqlite`.
- Tracing, dashboards, Dockerfile, compose/Helm examples, load testing.

---

## 8. Client sub-projects

All clients speak plain Matrix C-S API, so they also work against Synapse — and
Element works against Warp. Nothing proprietary in the wire protocol except
the `/_warp/admin/*` API used by the admin panel.

### 8.1 Admin web panel — Go + Vue (`apps/admin`)

- **Stack**: Vue 3 + TS + Vite + Pinia + Tailwind CSS, components from
  `apps/ui`. Built assets embedded into the `warp` binary and
  served at `/_warp/admin/`; no separate process.
- **Backend**: `server/internal/adminapi` (Go). Auth = Matrix login of a user
  with the admin flag; the panel uses the normal access token.
- **Features by priority**:
  1. Dashboard: users, rooms, events/min, federation status, storage driver, version.
  2. Federation switch, allow/deny list editor, per-server health (queue depth, backoff).
  3. Users: list/search, create, deactivate, reset password, devices, admin flag, registration tokens.
  4. Rooms: list/search, members, state viewer, purge, force-leave, alias management.
  5. Media: usage per user, quotas, purge remote media.
  6. Settings: registration on/off, rate limits, server notices, appservice registrations.
  7. Audit log of admin actions.
- **Starts**: after server Phase 1 (dashboard + users + federation switch),
  grows with each server phase.

### 8.2 Web client — Go + Vue (`apps/web`)

- **Frontend**: Vue 3 SPA in `apps/web/frontend`, built on the shared
  `apps/ui` component library and a Pinia-based Matrix store wrapping
  `matrix-js-sdk` (sync, rooms, timeline) with `matrix-sdk-crypto-wasm` for E2EE.
  Go is not a good fit for in-browser Matrix crypto; the Rust-Wasm crypto is
  what Element uses and is audited.
- **Go host** (`apps/web/cmd/warp-web`): serves the SPA, injects runtime config
  (homeserver URL, branding), handles `/.well-known` for client discovery,
  optional reverse proxy to the homeserver to avoid CORS. Can also be embedded
  into the `warp` binary behind `web_client.enabled: true`.
- **Feature order**: login/register → room list + timeline → send text/media →
  read receipts, typing → invites/joins, room settings → E2EE (device
  verification, key backup) → threads, reactions, spaces → voice messages,
  calls (much later).
- **Starts**: after server M1.

### 8.3 Desktop client — Go (`apps/desktop`)

- **Stack**: Wails v3. The UI is the same Vue frontend as `apps/web` (imported
  as a workspace package), so web and desktop share every screen.
- **Go side**: `mautrix-go` client with `goolm` (pure Go Olm/Megolm, no cgo)
  for E2EE, local encrypted SQLite store for sync state and keys, OS keychain
  for the access token, native notifications, tray icon, auto-update.
  Rationale: on desktop, doing sync + crypto in Go instead of in the webview
  gives a persistent local store, background sync, and lets the frontend stay
  thin — the Vue store talks to Go via Wails bindings instead of
  `matrix-js-sdk`. The store therefore has two backends (`js-sdk` in the
  browser, `wails` on desktop) behind one interface.
- **Targets**: Windows, macOS, Linux.
- **Starts**: once the web client has a stable room list + timeline.

### 8.4 Android app — Flutter (`apps/mobile`)

- **Stack**: Flutter + `matrix_dart_sdk` (famedly) + `flutter_vodozemac` for
  E2EE, `flutter_secure_storage`, FCM/UnifiedPush for push (via the server's
  push gateway support from Phase 8), Riverpod for state.
- **Feature order**: login → room list → timeline + send → push notifications
  → E2EE + verification → media → calls (later).
- Uses Simplified Sliding Sync when the server has it (Phase 10) for fast
  startup; falls back to `/sync`.
- **Starts**: after server Phase 8 (push) for a useful MVP; UI work can begin
  after M1.

### 8.5 iPhone app — future

- Same Flutter codebase; work items are APNs push (needs a push gateway such as
  Sygnal, or a Warp-native one), iOS-specific secure storage and keychain,
  App Store review. Deferred until the Android app is stable.

---

## 9. Testing strategy

| Level | Tool | What |
|---|---|---|
| Unit | `go test`, table-driven | `internal/matrix` (100% of spec examples); storage against all three drivers |
| Component | `httptest` | Each API package with a fake roomserver/userapi; federation gate tests (routes 404 when disabled, resume when enabled) |
| Integration | **Complement** (Docker) | Two profiles: `federation=off` (C-S tests only) and `federation=on`; track pass counts as the primary progress metric |
| Interop | Manual + scripted | Federate a dev instance with a Synapse in Docker; join `#matrix:matrix.org` |
| Fuzz | `go test -fuzz` | Canonical JSON, event parsing, X-Matrix header parsing, federation PDU intake |
| Frontend | Vitest + Playwright | `apps/ui` components; end-to-end login/send/receive against a Warp container |
| Mobile | Flutter `test` + `integration_test` | Against the same Warp container |

---

## 10. Milestones

| # | Milestone | Definition of done |
|---|---|---|
| M1 | "Hello Matrix" | Element Web can register, log in, create a room, send messages, see them after reload — with federation **off** (server Phases 0–4). Admin panel shows dashboard, users, federation switch. |
| M2 | "On the network" | Federation toggled on from the admin panel; Warp joins a room on matrix.org; Synapse users join a Warp room; toggling off stops remote traffic cleanly (Phase 5). |
| M3 | "Daily driver" | Warp web client: E2EE rooms with cross-signing and key backup, images/files, push (Phases 6–8). Desktop client runs the same UI via Wails. |
| M4 | "Pocket server" | Android app with push and E2EE; bridges (mautrix) run via the AS API; sliding sync; PocketBase driver at parity (Phases 9–10). |
| M5 | "Everywhere" | iOS build of the Flutter app in TestFlight. |

---

## 11. Reference material

- Spec: https://spec.matrix.org/latest/ — start with *Room Versions* and the
  *Server-Server API* appendices.
- Dendrite (architecture reference; read, don't paste): https://github.com/element-hq/dendrite
- `gomatrixserverlib` (test vectors): https://github.com/matrix-org/gomatrixserverlib
- Complement: https://github.com/matrix-org/complement
- Federation tester: https://federationtester.matrix.org
- PocketBase as a Go framework: https://pocketbase.io/docs/go-overview/
- `mautrix-go` + `goolm`: https://github.com/mautrix/go
- `matrix-js-sdk` / `matrix-sdk-crypto-wasm`: https://github.com/matrix-org/matrix-js-sdk
- Wails v3: https://v3alpha.wails.io
- `matrix_dart_sdk`: https://github.com/famedly/matrix-dart-sdk
- Synapse admin API (feature checklist for our admin panel): https://element-hq.github.io/synapse/latest/usage/administration/admin_api/

---

## 12. Open questions

1. **State storage model**: Dendrite's snapshot + block NIDs vs. per-event
   full-state rows. Decide in Phase 3 after a spike with a 10k-event room.
2. **Room version breadth** for federation compatibility (v6+ probably enough).
3. **Presence** default on/off.
4. **PocketBase scope**: full storage driver as specified, or only media
   filesystem + admin auth on top of the `sqlite` driver? The latter is far
   less work for most of the benefit. Decide after the `sqlite` driver is done.
5. **Desktop sync engine**: Go (`mautrix-go`) as planned, or keep
   `matrix-js-sdk` in the webview for maximum code sharing with web? Prototype
   both in a week and pick.
6. **Push gateway for mobile**: run Sygnal, or build a small Warp-native
   FCM/APNs gateway in Go?