# Conventions

Code-style and process expectations across the workspace. Most of these
exist because something already went wrong without them.

## Naming

- Containers are length-bounded by `nixos-container` (≤ 11 chars).
- Sub-agents are `h-<name>` with `<name>` ≤ 9 chars.
- The manager is `hm1nd` (no `h-` prefix, fixed name).
- `MAX_AGENT_NAME` in `lifecycle.rs` enforces the cap.
- Per-agent web UI port = `WEB_PORT_BASE + FNV1a(name) % WEB_PORT_RANGE`
  (8100..8999) for every agent including the manager; dashboard
  `cfg.dashboardPort` (default 7000).

## Identity = socket

There are no auth tokens on the per-agent unix sockets. The socket
*path* identifies the principal; perms come from "who has the
bind-mount." A sub-agent only sees its own `/run/hive/mcp.sock`; the
manager has access to its privileged socket; hive-c0re owns the host
admin socket.

## Recipient sentinels

A few recipient names are reserved by the broker and have special
meaning that ordinary agent labels can never collide with — agent
name validation rejects any character outside `[a-z0-9_-]`, so the
angle-bracket and asterisk shapes below are structurally safe.

- `*` — broadcast: deliver to every running agent except the sender
  (`agent_server::handle_send` fans out via `Coordinator::broadcast_send`).
- `operator` — the human at the dashboard. Messages accumulate in the
  inbox view; no agent ever `recv`'s them.
- `<parent>` — the sender's parent per `topology.json`. Rewritten at
  send time by `topology::resolve_recipient`: looks up
  `parent_of(sender)` and falls back to `operator` when the sender is
  a root agent (or absent from topology entirely). Lets agents address
  their parent without learning the label, so runtime reparenting
  propagates with zero agent-side restart.

When the resolver rewrites `<parent>`, the broker stores the
*resolved* label as the message's recipient — the dashboard and
recv side both see the real route. The sentinel is purely a
send-time addressing convenience.

## Wire protocol

JSON line-delimited over unix sockets in both directions (host admin
/ manager / agent). SSE streams (`/dashboard/stream` on hive-c0re,
`/events/stream` on the per-agent web UIs) are `text/event-stream`;
each frame carries a `seq` field for the snapshot-dedupe dance
(see `docs/web-ui.md`). Request/response types live in `hive-sh4re`
— change them in one place. The dashboard event vocabulary lives
in `hive-c0re::dashboard_events::DashboardEvent`.

### Broker delivery + ack cycle

`AgentRequest::Recv` is the only path that delivers messages to an
agent. Always returns a list (`Messages { messages }`) — empty when
nothing's pending, single-pop when `max = None` (default 1, the
single-message behaviour), batched up to `max` when caller asks for
more (server-side cap is 32; values above clamp silently).
`wait_seconds` long-polls for the first message; once one arrives —
or one is already pending — the call drains up to `max` in total
before returning, so a single `Recv` call coalesces a burst.

Per-row bookkeeping inside the broker:

- `delivered_at = NOW` set on every popped row.
- Each recipient has an in-memory `unacked_ids` list of every row
  delivered since the last `AckTurn`.
- `redelivered = true` on a row if `RequeueInflight` resurfaced it
  (the harness prepends a "may already be handled" hint when this
  flag is set so the per-message warning is visible).

`AgentRequest::AckTurn` closes out the in-memory list — the harness
fires it after `TurnOutcome::Ok`, marking every message popped since
the last ack as fully handled. Claude doesn't see this surface; it's
strictly a harness↔broker pairing. On `TurnOutcome::Failed` the
harness intentionally skips the ack so the unacked rows stay
in-flight in the DB and get picked up by the next requeue sweep.

`AgentRequest::RequeueInflight` is the recovery pair: fired by the
harness exactly once at boot, before the serve loop starts. Catches
the crashed-mid-turn / OOM-killed / container-restarted cases where
a previous harness session popped messages but never drove them to
a clean turn-end. Resets `delivered_at` back to NULL on every
unacked row (so the next `Recv` pops them again), and remembers
each id in a per-recipient in-memory set so the next `Recv` can tag
the row with `redelivered: true`. Idempotent + cheap when there's
nothing in flight, so the at-boot fire is unconditional.

## Async forms

Dashboard + per-agent mutating forms carry `data-async`; a delegated
`submit` listener in `assets/tabs.js` intercepts, shows a spinner,
POSTs `application/x-www-form-urlencoded` (axum's `Form` extractor
rejects multipart), calls `refreshState()` on success. New mutating
forms should add `data-async` and optionally `data-confirm` (for a
JS-side `confirm()` prompt) or `data-prompt="…"` (for a
`window.prompt()` whose answer goes into a hidden input named by
`data-prompt-field`, default `note`).

`refreshState` defers automatically when `document.activeElement`
sits inside a managed section so the operator's typing isn't lost;
collapsible `<details data-restore-key=…>` survive the re-render
via `snapshotOpenDetails` / `restoreOpenDetails`.

## `rebuild` is the reconcile verb

`lifecycle::rebuild` idempotently rewrites
`/etc/nixos-containers/<C>.conf` (`PRIVATE_NETWORK=0`, clears
`HOST_ADDRESS` / `LOCAL_ADDRESS`, sets `EXTRA_NSPAWN_FLAGS`),
regenerates `applied/<name>/flake.nix`, writes the systemd limits
drop-in, then `nixos-container update` + stop + start.

Anything that changes per-container state on the host should be
re-applied here so a manual `↻ R3BU1LD` from the dashboard is
sufficient to recover.

## Actions are factored

`approve` / `deny` / `destroy` (and the lifecycle helper) live in
`actions.rs` / `dashboard.rs`. The admin socket and the dashboard
POST handlers both call into them so the two surfaces never drift.

## Commit messages

Short, lowercase, no `Co-Authored-By` trailer. Imperative mood, no
period. Body explains *why* if non-obvious; otherwise the subject
alone is fine. Wrap at ~72 cols.

## Commit before test

Stage and commit when work *looks* ready, then run validation
(`cargo check`, `nix flake check`, real deploy). Failures get a
follow-up commit rather than an amend. The commit history is the
work log; rewriting it loses signal.