iris_x_hermes/docs/04-wire-protocol.md

# 04 — Wire Protocol

JSON frames over a single WebSocket. One connection per device. Text frames are
JSON; media travels as **binary frames** (chunked) referenced by a header frame.

## Envelope

Every frame:

```json
{
  "v": 1,
  "id": 42,                 // optional; present on requests + their responses
  "type": "message",        // frame type (below)
  "chat_id": "default",   // optional; scope for chat-scoped frames
  "thread_id": "t_123",           // optional
  "payload": { }             // type-specific object
}
```

- `v` — protocol version (currently `1`). Server rejects unknown major versions.
- `id` — request id (client-chosen). Responses/acks echo it. Events have no `id`.
- `chat_id` / `thread_id` — top-level for convenience; may also be in `payload`.
- `cursor` — outbox cursor the frame was parked under. Present **only** on
  frames replayed by `sync` (live frames carry none). The app compares it
  against `last_pushed_cursor` from `hello.ack` to skip re-notifying frames
  that already woke the device via push (`08-push.md` §8.7).
- Unknown `type`s are ignored (forward-compat); unknown `payload` fields ignored.

**Binary media frames** are not JSON. A media transfer is: one JSON header frame
(`media.upload.start` / `media.pull` ack) followed by raw binary frames, then a
JSON `media.upload.end` / final ack. See `07-media.md`.

## Server → App (events / responses)

### `hello.ack`

Pairing succeeded.

```json
{"type":"hello.ack","payload":{
  "server_caps":{"streaming":true,"reasoning":true,"tools":true,"media":true,
                 "search":true,"push":"fcm","pickers":true},
  "sync_cursor":1042,
  "last_pushed_cursor":1040,
  "channels":[{"chat_id":"default","name":"Default","kind":"default","is_default":true}]
}}
```

`last_pushed_cursor` is the highest outbox cursor already delivered to THIS
device via the push backend (0 = never). The app skips system notifications
for sync-replayed frames with `cursor <= last_pushed_cursor` — they already
woke the device via push (dedupe, `08-push.md` §8.7).

### `message`

A final / standalone message.

```json
{"type":"message","chat_id":"default","thread_id":null,
 "payload":{
   "message_id":"m_9001","role":"assistant",
   "text":"Here is the answer…",
   "reasoning":"The user asked… so I will…",   // optional; render ABOVE text
   "media":[{"media_id":"md_5","kind":"video","mime":"video/mp4","size":123456,
             "filename":"clip.mp4"}],           // optional
   "reply_to":"m_8999",                          // optional
   "model":"qwen3-27b","tokens":11,"ts":1724000000000,
   "runtime":{"model":"qwen3-27b","context_pct":38,"cwd":"~",
              "latency":22.5,"cost":0.0012}      // optional; see below
 }}
```

`role` ∈ `user | assistant | system | cron`. `reasoning` present only when the
agent produced reasoning and `show_reasoning` is on.

`runtime` (optional) is the **structured runtime-metadata footer** the app
renders under final assistant messages (Telegram-style). The gateway ALWAYS
sends it on final assistant messages; whether/what is shown is a **per-app
setting** (Settings → Runtime footer), NOT a hermes config. Keys (all
optional; absent when the data is unavailable, e.g. local models have no
cost):

- `model` — bare model id, vendor prefix dropped (`gpt-5.4`)
- `context_pct` — last-call context occupancy, 0-100 (int)
- `cwd` — home-relative working dir (`~`)
- `latency` — wall-clock turn duration, seconds (float)
- `cost` — turn cost, USD (float)

### `message.start` / `message.update` / `message.stop`

Streaming a bubble. `update` carries the **full** current text (app replaces).

```json
{"type":"message.start","chat_id":"…","payload":{"message_id":"m_9002","role":"assistant"}}
{"type":"message.update","chat_id":"…","payload":{"message_id":"m_9002","text":"partial…"}}
{"type":"message.stop","chat_id":"…","payload":{"message_id":"m_9002","final_text":"full…",
    "reasoning":"…","model":"…","tokens":11,
    "runtime":{"model":"…","context_pct":38,"cwd":"~","latency":22.5}}}
```

### `message.deleted`

The given message(s) were deleted from a chat/thread. Response to a
`message.delete` request (`id` set) **and** broadcast to every device so all of
them drop the message(s) from their cache. Also outboxed, so a device that was
offline learns of the deletion on its next `sync`.

```json
{"type":"message.deleted","id":30,"chat_id":"default","thread_id":null,
 "payload":{"message_ids":["m_9001","m_9002"]}}
```

### `commentary`

Intermediate assistant beat (between tool iterations).

```json
{"type":"commentary","chat_id":"…","payload":{"message_id":"m_9003","text":"Let me inspect the repo first."}}
```

### `tool.start` / `tool.progress` / `tool.end`

**Structured** tool events. The app decides how much to show (everything /
truncated / nothing).

```json
{"type":"tool.start","chat_id":"…","payload":{
   "index":3,"name":"terminal","preview":"pytest -q","args":{"command":"pytest -q"},"emoji":"💻"}}
{"type":"tool.progress","chat_id":"…","payload":{"index":3,"name":"terminal","note":"running…"}}
{"type":"tool.end","chat_id":"…","payload":{"index":3,"name":"terminal","ok":true,"duration":12.4,
   "output_preview":"12 passed"}}
```

`args` may be large; the app truncates per its setting. `output_preview` is a
short tail (full output is not streamed — it lives in agent history).

`emoji` is a cosmetic per-tool glyph resolved server-side via hermes'
`get_tool_emoji` (active-skin overrides, then the tool registry's per-tool
`emoji` — e.g. `read_file` 📖, `write_file` ✍️, `terminal` 💻). Omitted when
the tool is unknown, so the app falls back to its own default glyph.

### `todo.update`

The agent's **full current todo list** for a chat/thread lane (last-write-wins).
Emitted whenever the `todo` tool completes — the tool *result* is the
authoritative list, which also covers `merge` writes (whose args carry only
the changed items) and read-only calls — and, as a **snapshot**, right after
`hello` when a device opens its event stream.

```json
{"type":"todo.update","chat_id":"default","thread_id":null,"payload":{
   "todos":[
     {"id":"1","content":"Scaffold the module","status":"completed"},
     {"id":"2","content":"Wire the store","status":"in_progress"},
     {"id":"3","content":"Add tests","status":"pending"}
   ]}}
```

`status` is one of `pending | in_progress | completed | cancelled`. The frame
is **ephemeral**: it is never outboxed, so a reconnecting device learns the
current list from the snapshot (not a replay), and a gateway restart drops it
(the agent re-emits on the next `todo` call). The app renders it as a compact
scrollable strip above the composer (max 3 lines; auto-scrolls to the item
whose status just changed) and hides it once the list is empty or fully
resolved.

### `typing` / `typing.stop`

```json
{"type":"typing","chat_id":"…","payload":{"on":true}}
```

### `notification`

In-app banner (foreground) and/or push mirror (background).

```json
{"type":"notification","chat_id":"…","payload":{
   "kind":"channel_renamed","title":"ARIA","body":"Renamed topic to …","ts":1724000000000}}
```

`kind` ∈ `channel_renamed | channel_created | cron | approval | clarify | generic`.

### `picker.model` / `picker.choice` / `picker.clarify` / `picker.approval` / `picker.confirm`

Interactive prompts. App renders a native picker; answers via `picker.select`.

`picker.choice` is implemented (the generic finite-choice menu used by
`/reasoning`, `/fast`, and any future finite-choice slash command — hermes
calls the adapter's `send_choice_picker` when the platform supports it).
The server runs the command's selection callback on `picker.select` and
delivers its reply as a normal `message` in the picker's chat. The frame is
outboxed (a reconnecting device re-renders a still-pending picker); pending
state is in-memory only, so a gateway restart expires it (a stale
`picker.select` is a no-op). With no live device the adapter reports failure
and hermes falls back to the text status card.

```json
{"type":"picker.model","chat_id":"…","payload":{
   "picker_id":"pm_1","current_model":"qwen3-27b","current_provider":"local",
   "providers":[{"id":"local","label":"Local","models":[{"id":"qwen3-27b","label":"Qwen3 27B"}]}]}}
{"type":"picker.choice","chat_id":"…","payload":{
   "picker_id":"pc_1","title":"Reasoning effort","choices":[
     {"value":"low","label":"Low"},{"value":"high","label":"High","is_current":true}]}}
```

### `channel.list` / `channel.created` / `channel.renamed` / `channel.deleted`

Channel directory updates. **Broadcast to all connected devices** (no explicit
subscribe; the server pushes to every open WS).

```json
{"type":"channel.created","payload":{"chat_id":"chan_7","name":"Cron Reports",
   "kind":"channel","parent_chat_id":null}}
```

`channel.created` may carry `"auto":true` for a thread the gateway minted
itself for an incoming message (auto-threading): the name is an instant
derived title, and a follow-up `channel.renamed` upgrades it to the model's
title.

### `history`

Response to a `history` request. Returns a page of messages for a chat/thread.

```json
{"type":"history","id":20,"chat_id":"default","thread_id":null,
 "payload":{
   "messages":[
     {"message_id":"m_8990","role":"user","text":"Hi","ts":1723990000000},
     {"message_id":"m_8991","role":"assistant","text":"Hello!","reasoning":"…",
      "model":"qwen3-27b","tokens":8,"ts":1723990001000}
   ],
   "has_more":true,
   "oldest_message_id":"m_8990"
 }}
```

`messages` are ordered oldest → newest. Paginate with `before_message_id` in the
request. The app uses this to **populate the initial view** when a channel is
opened (complements `sync`, which only replays undelivered outbox frames).

### `commands.catalog`

Request (app → server, empty payload) and response: the gateway's
slash-command catalog for the app's `/` drawer. Derived from hermes' central
`COMMAND_REGISTRY` (the same source the gateway help and the Telegram command
menu use), restricted to commands available on gateway surfaces, plus
plugin-registered commands. The app fuzzy-matches the typed prefix
client-side (no `commands.complete` round-trip).

```json
{"type":"commands.catalog","id":21,"payload":{
   "commands":[
     {"name":"/new","description":"Start a new session (fresh session ID + history)","args_hint":"[name]","category":"Session","aliases":["/reset"]},
     {"name":"/model","description":"Switch model","args_hint":"<provider/model>","category":"Configuration","aliases":[]},
     {"name":"/status","description":"Show session status","args_hint":"","category":"Info","aliases":[]}
   ]}}
```

`name`/`aliases` carry the leading slash; `args_hint` is the registry's
argument placeholder (empty when the command takes none).

### `commands.complete`

Response to a `commands.complete` request. Autocomplete matches for a typed prefix.

```json
{"type":"commands.complete","id":22,"payload":{
   "prefix":"/mod",
   "matches":[
     {"name":"/model","description":"Switch model","args_hint":"<provider/model>"}
   ]}}
```

### `agent.busy` / `agent.idle`

Agent lifecycle for a chat/thread. App shows a "thinking…" indicator on `busy`.

```json
{"type":"agent.busy","chat_id":"default","thread_id":null,
 "payload":{"reason":"processing"}}
{"type":"agent.idle","chat_id":"default","thread_id":null,"payload":{}}
```

`reason` ∈ `processing | tool | waiting_input | cron`.

### `search.results`

```json
{"type":"search.results","id":7,"payload":{
   "query":"deploy","scope":"all","hits":[
     {"message_id":"m_123","chat_id":"chan_7","thread_id":null,
      "role":"assistant","snippet":"…deploy the service…","ts":1723900000000}]}}
```

### `media.offer`

Agent-sent media is available; app pulls bytes.

```json
{"type":"media.offer","chat_id":"…","payload":{
   "media_id":"md_5","kind":"video","mime":"video/mp4","size":123456,"filename":"clip.mp4"}}
```

### `read.receipt`

The gateway acknowledges that the agent has received and started processing
the user's message. The app uses it to show ✓✓ on user bubbles.

```json
{"type":"read.receipt","chat_id":"default","payload":{"message_id":"m_9001"}}
```

Emitted to the originating connection when a `message.send` is accepted for
processing (at the moment it is handed to the agent), for user-originated
messages only.

### `status`

Gateway health state. Broadcast to all connected clients at startup
(`state: "online"`) and to late joiners on `hello.ack`. The gateway also
broadcasts `state: "restarting"` on its shutdown path (restart/stop), right
before closing the sockets — the app posts the "Gateway restarting" chat
notice immediately on that frame (the socket can take up to the ~20 s ping
timeout to actually drop, so the notice must not wait for the disconnect);
a plain network drop shows just the reconnect banner. `degraded` is reserved
for future use.

```json
{"type":"status","payload":{"state":"online"}}
```

`state` ∈ `online | restarting | degraded`.

### `error`

```json
{"type":"error","id":7,"payload":{"code":"not_found","message":"chat_id unknown"}}
```

`code` ∈ `auth | not_found | rate_limited | media_too_large | unsupported | internal`.

### `pong`

Keepalive reply to `ping`.

## App → Server (requests / actions)

### `hello`

First frame; auth + caps.

```json
{"type":"hello","payload":{
   "token":"<IRIS_TOKEN>","device_id":"dev_a1b2","device_name":"MIX 2S",
   "caps":{"min_protocol":1,"media":true,"push":"fcm"},
   "fcm_token":"<FCM token>","ntfy_topic":"<topic, if ntfy>"}}
```

### `message.send`

Send text (or a `/slash-command`).

```json
{"type":"message.send","id":10,"chat_id":"default","thread_id":null,
 "payload":{"text":"/model qwen3-27b","reply_to":"m_9001","media_refs":["mu_1"],
            "auto_thread":false}}
```

`media_refs` reference completed `media.upload`s to attach.
`auto_thread` (optional, default false) asks the gateway to mint a fresh
thread for the message (auto-threading, `06-channels-cron-search.md` §6.3):
honored only in a channel's flat lane (`thread_id` null) with non-empty text
that is not a slash command. The gateway then broadcasts
`channel.created {auto:true}` and the echo / agent turn carry the new
`thread_id`.

### `media.upload.start` / (binary) / `media.upload.end`

See `07-media.md`.

```json
{"type":"media.upload.start","id":11,"payload":{
   "media_ref":"mu_1","kind":"image","mime":"image/jpeg","size":204800,"filename":"a.jpg"}}
// … binary frames …
{"type":"media.upload.end","id":11,"payload":{"media_ref":"mu_1","sha256":"…"}}
```

### `media.upload.ack`

Server → App response to `media.upload.end`: the ref is cached and may now be
referenced in a `message.send` `media_refs`. Failures use `error` frames instead.

```json
{"type":"media.upload.ack","id":11,"payload":{"ok":true,"media_ref":"mu_1"}}
```

### `media.pull`

Request agent-sent media bytes.

```json
{"type":"media.pull","id":12,"payload":{"media_id":"md_5"}}
// server replies: binary frames, then {"type":"media.pull.end","id":12,"payload":{"ok":true}}
```

### `picker.select`

Answer an interactive picker.

```json
{"type":"picker.select","id":13,"payload":{"picker_id":"pm_1","value":"local/qwen3-27b"}}
```

### `channel.create` / `channel.rename` / `channel.set_default` / `channel.delete`

```json
{"type":"channel.create","id":14,"payload":{"name":"Cron Reports","kind":"channel"}}
{"type":"channel.rename","id":15,"chat_id":"chan_7","payload":{"name":"Reports"}}
{"type":"channel.set_default","id":16,"chat_id":"chan_7","payload":{}}
```

`channel.delete` is a **hard delete**: the channel/thread row is removed from
the directory and the lane's history is wiped from the outbox and the hermes
session store (no search trace, not recoverable). Deleting a channel also
removes its threads. The default channel cannot be deleted.

### `search`

```json
{"type":"search","id":17,"payload":{"query":"deploy","scope":"all"}}
{"type":"search","id":18,"payload":{"query":"deploy","scope":"chat","chat_id":"chan_7","thread_id":null}}
```

`scope` ∈ `all | chat`.

### `read.receipt`

App → server: "user has viewed this message." Server stores the read state and
broadcasts to other devices (for multi-device ✓✓ sync). The app uses it to
mark messages as read locally (✓✓ on user bubbles).

```json
{"type":"read.receipt","payload":{"chat_id":"default","message_id":"m_9001"}}
```

### `history`

Load a page of messages for a chat/thread (initial open, scroll-up pagination).

```json
{"type":"history","id":20,"chat_id":"default","thread_id":null,
 "payload":{"before_message_id":"m_8990","limit":50}}
```

`before_message_id` — return messages older than this (omit for newest page).
`limit` — max messages (default 50, max 200).

### `message.delete`

Completely delete the given message(s) from a chat/thread. The server removes
them from the outbox (so `history`/`sync` no longer return them) **and** from
the hermes session store (so no search trace survives and they are not
recoverable), then broadcasts `message.deleted` to every device. Idempotent: a
message already gone (pruned by retention) still yields a `message.deleted`
broadcast so live caches drop it.

```json
{"type":"message.delete","id":30,"chat_id":"default","thread_id":null,
 "payload":{"message_ids":["m_9001","m_9002"]}}
```

### `commands.catalog`

Fetch the full slash-command catalog (for the `Menü` bottom sheet).

```json
{"type":"commands.catalog","id":21,"payload":{}}
```

### `commands.complete`

Autocomplete for a typed `/prefix`.

```json
{"type":"commands.complete","id":22,"payload":{"prefix":"/mod"}}
```

### `agent.stop`

Stop the current agent turn (abort generation / tool execution).

```json
{"type":"agent.stop","id":23,"chat_id":"default","thread_id":null,"payload":{}}
```

### `agent.steer`

Inject a steering message mid-turn (redirects the agent without a new turn).

```json
{"type":"agent.steer","id":24,"chat_id":"default","thread_id":null,
 "payload":{"text":"Actually, focus on the error case."}}
```

### `sync`

Reconnect catch-up. Replays **undelivered outbox frames** (frames sent while
this device was offline). Does NOT load full history — use `history` for that.

```json
{"type":"sync","id":19,"payload":{"cursor":1042}}
// server replays outbox frames with cursor > 1042, then {"type":"sync.done","id":19,"payload":{"cursor":1099}}
```

### `fcm.register`

Update push token.

```json
{"type":"fcm.register","payload":{"fcm_token":"<new>","ntfy_topic":"<topic>"}}
```

### `ping`

Keepalive. `{"type":"ping","payload":{"ts":1724000000000}}` → `pong`.

## Ordering & reliability

- Frames are ordered per connection (TCP/WS). Streaming `message.update` frames
  for a `message_id` are monotonic; the app may coalesce to the latest.
- Terminal frames (`message`, `message.stop`, `message.deleted`, `tool.end`,
  `notification`, `picker.*`, `channel.*`, `agent.busy`, `agent.idle`,
  `history`, `commands.catalog`, `commands.complete`) are **never dropped**
  under backpressure; only intermediate `message.update`/`tool.progress` are
  coalesced.
- Anything not delivered live goes to the **outbox** and is replayed by `sync`.
- **Broadcast:** channel directory events (`channel.*`) and read-receipts are
  pushed to **all** connected devices for that gateway (no subscribe step).
- Requests get exactly one response or `error` (matched by `id`).