simon
31e539052a
Replace separate accel/tap snapshot UART commands with one clients[] response that omits unsubscribed fields; remove snapshot handlers and CLI commands. Add goTool/docs for WebSocket streams and REST; tap-snapshot REST uses CACHE_STATUS. Co-authored-by: Cursor <cursoragent@cursor.com>
349 lines
10 KiB
Markdown
349 lines
10 KiB
Markdown
# WebSocket API
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`go run . -port /dev/ttyUSB0 serve` exposes two WebSocket endpoints. They share the same UART link but serve different purposes.
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| URL | Port (default) | Role |
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|-----|----------------|------|
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| `ws://localhost:8080/ws` | Dashboard (`-addr`) | Server → client only: full `DashboardState` JSON (~2 s poll + live-stream accel/tap) |
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| `ws://localhost:8081/ws` | External API (`-api-addr`) | Request/response commands + optional **accel** / **tap** push streams |
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Disable the external server with `-api-addr ""`.
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CLI overview and UART commands: [`../README.md`](../README.md). HTTP endpoints: [`API_REST.md`](API_REST.md).
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---
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## External API (`:8081/ws`)
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### Connection flow
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1. Connect → server sends **`hello`** (receive off; lists available commands).
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2. Send JSON commands → server replies with a matching `*_status` or `client_list` message (one reply per command).
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3. After `set_stream` / `set_tap_stream` with `enable: true`, the server may send **`accel`** and/or **`tap`** messages **without** a prior command (push stream).
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Commands and stream pushes are multiplexed on one socket. While streaming, always parse `type` and branch (status vs sample vs error).
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### Two layers (accel and tap)
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| Layer | Commands | Effect |
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|-------|----------|--------|
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| **Firmware (ESP-NOW)** | `set_accel_stream`, `set_tap_notify` | Per `client_id`: slave sends accel or tap kinds to the master |
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| **This connection (host)** | `set_stream`, `set_tap_stream` | Whether **you** receive push JSON and at what rate (`interval_ms`, 1 ms … 10 s) |
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- **Accel UART polling** runs only if at least one connection has `receive_accel: true` **and** at least one slave streams accel (`set_accel_stream` or dashboard).
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- **Tap UART polling** runs only if at least one connection has `receive_tap: true` (`set_tap_stream`). `set_tap_notify` alone does **not** poll.
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Typical sequence:
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1. `list_clients` → slave IDs
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2. Per slave: `set_accel_stream` / `set_tap_notify` as needed
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3. `set_stream` and/or `set_tap_stream` with `"enable": true`
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4. Read push messages in a loop
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There is **no per-slave filter** on push messages: each `accel` contains all cached slaves; each `tap` contains all visible events. Filter by `client_id` in your app.
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---
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## Push stream messages
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These are the samples you get after enabling receive. Interval is per WebSocket connection; the server UART poll uses the **minimum** `interval_ms` among all subscribers that want accel or tap.
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### `accel` (type `"accel"`)
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Sent only when `set_stream` has `enable: true`, a slave streams accel, and the poll tick fires for this connection.
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**Success** — all slaves with a cache entry on the master (not only those with `valid: true`):
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```json
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{
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"type": "accel",
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"t": 1716900123456789012,
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"success": true,
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"clients": [
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{
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"client_id": 16,
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"valid": true,
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"x": 12,
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"y": -34,
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"z": 16384,
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"age_ms": 8
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},
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{
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"client_id": 42,
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"valid": false
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}
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]
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}
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```
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| Field | Meaning |
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|-------|---------|
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| `t` | Unix timestamp in **nanoseconds** when the host read the cache |
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| `success` | `true` if `CACHE_STATUS` succeeded |
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| `clients[]` | One entry per slave slot in the master cache |
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| `client_id` | ESP-NOW client id (same as `list_clients`) |
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| `valid` | `false` if no sample yet or stale; omit `x`/`y`/`z` when false |
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| `x`, `y`, `z` | Raw accelerometer LSB (BMA456, ±2 g scale on the pod) |
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| `age_ms` | Milliseconds since the master received this sample |
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**Failure** (e.g. UART busy):
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```json
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{
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"type": "accel",
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"t": 1716900123456789012,
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"success": false,
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"error": "uart busy"
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}
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```
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No `clients` array on failure.
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### `tap` (type `"tap"`)
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Sent only when `set_tap_stream` has `enable: true` and there is at least one event to show.
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Events appear when the master cache reports a new tap. Each event stays in push payloads for **`tap_display_min_ms`** (2000 ms, also in `hello`) after the API first saw it, even if the hardware age grows.
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**Success**:
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```json
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{
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"type": "tap",
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"t": 1716900123456789012,
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"success": true,
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"events": [
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{
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"client_id": 16,
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"valid": true,
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"kind": "single",
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"age_ms": 3,
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"shown_at_ms": 1717000000123
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}
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]
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}
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```
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| Field | Meaning |
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|-------|---------|
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| `t` | Unix timestamp in **nanoseconds** (poll time) |
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| `events[]` | All taps currently “on screen” for the API |
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| `client_id` | Slave that tapped |
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| `kind` | `"single"`, `"double"`, or `"triple"` |
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| `age_ms` | Age in the master cache when read |
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| `shown_at_ms` | Unix **milliseconds** when this host first included the event |
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If no events are visible, **no** `tap` message is sent on that tick (unlike accel, which can send empty `clients` only on success with cache data).
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**Failure**:
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```json
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{
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"type": "tap",
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"t": 1716900123456789012,
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"success": false,
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"error": "uart busy"
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}
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```
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---
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## Commands (request → response)
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Send one JSON object per message. Field `type` selects the command.
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### `hello` (server → client, on connect)
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```json
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{
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"type": "hello",
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"serial_port": "/dev/ttyUSB0",
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"interval_ms": 16,
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"tap_display_min_ms": 2000,
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"note": "set_tap_notify configures slave S/D/T only; set_tap_stream enables tap polling/push",
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"commands": [
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"list_clients",
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"set_stream", "get_stream",
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"set_accel_stream", "get_accel_stream",
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"set_tap_stream", "get_tap_stream",
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"set_tap_notify", "get_tap_notify",
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"set_led_ring", "get_battery"
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]
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}
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```
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### `list_clients`
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Request: `{"type":"list_clients"}`
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Response `client_list`:
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```json
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{
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"type": "client_list",
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"success": true,
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"clients": [
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{
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"id": 16,
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"mac": "aa:bb:cc:dd:ee:10",
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"version": 1,
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"available": true,
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"used": true,
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"last_ping": 1234,
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"last_success_ping": 1200,
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"accel_stream": false,
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"tap_notify_single": false,
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"tap_notify_double": false,
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"tap_notify_triple": false
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}
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]
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}
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```
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### `set_stream` / `get_stream` (receive accel on this connection)
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```json
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{"type":"set_stream","enable":true,"interval_ms":32}
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{"type":"get_stream"}
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```
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Response `stream_status`:
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```json
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{"type":"stream_status","receive_accel":true,"interval_ms":32,"success":true}
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```
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### `set_accel_stream` / `get_accel_stream` (firmware, per slave)
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`client_id` required (> 0).
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```json
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{"type":"set_accel_stream","client_id":16,"enable":true}
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{"type":"get_accel_stream","client_id":16}
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```
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Response `accel_stream_status`:
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```json
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{"type":"accel_stream_status","client_id":16,"enabled":true,"success":true}
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```
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### `set_tap_stream` / `get_tap_stream` (receive tap on this connection)
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```json
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{"type":"set_tap_stream","enable":true,"interval_ms":16}
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{"type":"get_tap_stream"}
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```
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Response `tap_stream_status`:
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```json
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{"type":"tap_stream_status","receive_tap":true,"interval_ms":16,"success":true}
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```
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### `set_tap_notify` / `get_tap_notify` (firmware, per slave)
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Per client: `single`, `double_tap`, `triple` required on set.
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```json
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{"type":"set_tap_notify","client_id":16,"single":true,"double_tap":false,"triple":false}
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```
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Broadcast: `"all_clients": true` with the three booleans.
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Response `tap_notify_status`:
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```json
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{
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"type": "tap_notify_status",
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"client_id": 16,
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"success": true,
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"single": true,
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"double_tap": false,
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"triple": false
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}
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```
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### `set_led_ring`
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Same JSON body as [`POST /api/led-ring`](API_REST.md#led-ring) with `"type":"set_led_ring"` added. Reply: `led_ring_status`.
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### `get_battery`
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Body: `{"type":"get_battery","all_clients":true}` or `"client_id":16`. Default if omitted: all clients.
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Reply: `battery_status` with `samples[]` (see REST doc).
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---
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## Examples
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### Accel stream
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```python
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import asyncio, json, websockets
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async def main():
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async with websockets.connect("ws://127.0.0.1:8081/ws") as ws:
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print(await ws.recv()) # hello
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await ws.send(json.dumps({"type": "list_clients"}))
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clients = json.loads(await ws.recv())["clients"]
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for c in clients:
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if not c.get("available"):
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continue
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await ws.send(json.dumps({
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"type": "set_accel_stream", "client_id": c["id"], "enable": True
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}))
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await ws.recv() # accel_stream_status
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await ws.send(json.dumps({"type": "set_stream", "enable": True, "interval_ms": 16}))
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await ws.recv() # stream_status
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while True:
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msg = json.loads(await ws.recv())
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if msg.get("type") != "accel":
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continue
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if not msg.get("success"):
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print("error:", msg.get("error"))
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continue
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for c in msg.get("clients", []):
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if c.get("valid"):
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print(c["client_id"], c["x"], c["y"], c["z"], "age", c.get("age_ms"))
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asyncio.run(main())
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```
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### Tap stream
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```python
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import asyncio, json, websockets
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async def main():
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async with websockets.connect("ws://127.0.0.1:8081/ws") as ws:
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print(await ws.recv()) # hello
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await ws.send(json.dumps({
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"type": "set_tap_notify", "client_id": 16,
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"single": True, "double_tap": False, "triple": False
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}))
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await ws.recv() # tap_notify_status
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await ws.send(json.dumps({"type": "set_tap_stream", "enable": True, "interval_ms": 16}))
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await ws.recv() # tap_stream_status
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while True:
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msg = json.loads(await ws.recv())
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if msg.get("type") == "tap" and msg.get("events"):
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for e in msg["events"]:
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print(e["client_id"], e["kind"], "age", e.get("age_ms"))
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asyncio.run(main())
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```
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---
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## Dashboard WebSocket (`:8080/ws`)
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Read-only from the browser’s perspective: the server pushes JSON whenever state changes. Clients do not send commands on this socket (messages are ignored).
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Payload shape: `DashboardState` — `updated_at`, `serial_port`, `uart_connected`, `live_stream`, `master`, `clients[]` (id, mac, accel, tap notify flags, battery, etc.). Accel/tap samples appear here when **Live stream** is enabled in the UI (`PUT /api/live-stream`).
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During OTA, additional messages with `"type":"ota_progress"` may appear on the same socket.
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Configure slaves via REST on `:8080` ([`API_REST.md`](API_REST.md)), not via this WebSocket.
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