docs/runicnpc/API.md

# RunicNPC — the API

**API version 2** (RunicNPC stage 2, 2026-09-30). This is the reference for other plugins. Why it has this
shape is in [PLAN.md](PLAN.md) §4 and the decisions D221–D238.

RunicNPC is called by name through `Call`, like any Oxide or Carbon plugin API. Every call is prefixed
`RunicNpc_`, so no hook of another plugin is ever matched by accident. Every call is a non-public method, which is
what Oxide's `Call` reaches by name (PLAN.md §1.2).

```csharp
[PluginReference] private Plugin RunicNPC;

int api = RunicNPC?.Call<int>("RunicNpc_ApiVersion") ?? 0;
if (api < 2) { /* too old for this caller: say so */ }

BasePlayer npc = RunicNPC.Call("RunicNpc_Spawn", position, "warden", "plugin:MyPlugin", null) as BasePlayer;
```

**The version moves when a call or a raised hook changes shape**, not on every release. `plugin.toml` in the
repository declares the same number, and the release's `manifest.json` carries it, so an installer or the
bridge can refuse a RunicNPC that is too old before it is loaded.

A call that cannot do what it was asked **returns null (or 0, or false) and says why in the server log**. Calls
that change data return the reason as a string instead, and null means success.

---

## Owners

Every NPC has an owner, and the owner decides its lifetime (PLAN.md §2).

| Owner | Who uses it | Lifetime |
|---|---|---|
| `run:<id>` | An event run, through the bridge | Never saved. Removed by the caller, or by `RunicNpc_DespawnOwner`. |
| `plugin:<name>` | Any other plugin | Never saved. **Removed when that plugin unloads.** Use your plugin's own name. |
| `placement:<id>` | RunicNPC itself | The NPC is never saved; the placement is, and spawns a fresh one at boot. Callers cannot spawn with this owner. |

---

## Calls

### `RunicNpc_ApiVersion()` → `int`

The API version: `2`.

### `RunicNpc_Spawn(Vector3 at, string profile, string owner, JObject overrides)` → `BasePlayer`

Spawns one NPC now, or returns null.

- `owner` must be `run:<id>` or `plugin:<name>`.
- `overrides` may change any profile value for this NPC only, in the profile's own shape (below). It may be null.
  For example: `{"health": 500, "names": ["Captain"], "movement": {"mode": "route:gate", "radius": 0}}`. Arrays
  are replaced, not merged. The merged profile is validated like a saved one.
- A roamer must stand on Rust's navmesh: within 3 m across and 2 m up or down of `at`. A sentry may stand
  anywhere.
- It is refused until the map's navmesh is built, which takes 8–10 minutes on a map's first boot.

Refusals: an unknown or refused profile, a bad owner, a failed override, a spot off the navmesh, a cap an admin has
set, or a navmesh that is not built yet.

### `RunicNpc_Despawn(ulong netId)` → `int`

Removes one NPC by its net id. Returns 1, or 0 if it is not one of RunicNPC's. A placement's NPC comes back after
its respawn delay.

### `RunicNpc_DespawnOwner(string owner)` → `int`

Removes every NPC of `owner`, and returns how many it removed.

### `RunicNpc_List(string owner)` → `List<Dictionary<string, object>>`

The live NPCs of `owner`; null lists them all. Each has:

| Key | Type | |
|---|---|---|
| `netId` | `ulong` | |
| `profile`, `name`, `owner`, `kit` | `string` | The kit is the one picked for this NPC. |
| `placement` | `string` | Its placement's id, or null. |
| `position`, `home` | `{x, y, z}` | `home` is where it spawned: where it wanders around, and walks back to before it sleeps. |
| `health`, `maxHealth` | `float` | |
| `movement` | `string` | `wander`, `monument` or `route:<name>`. |
| `rest` | `string` | `Awake`, `GoingHome` or `Asleep` (D235). |
| `state` | `string` | Rust's AI state: `Idle`, `Roam`, `Chase`, `Combat` and so on. |
| `leashes` | `int` | How many times it has given up a chase at its chase range. |

### `RunicNpc_Profiles()` → `JObject`

`{"managed": bool, "profiles": {name: profile, …}, "refused": {name: reason, …}}`. A refused profile is kept in
the file but never spawns (a kit the server lacks, for example).

### `RunicNpc_SetProfiles(JObject all)` → `Dictionary<string, string>`

Replaces the whole profile set with `all` (`{name: profile, …}`), as a site does on every push, and **marks the
server managed** (D221). It returns the profiles refused and why; the rest are in use at once. A placement whose
profile has gone waits, and spawns again when the profile returns (D237).

### `RunicNpc_Placements()` → `List<Dictionary<string, object>>`

Each placement as `{id, placement, alive, waiting, lastError}`. `placement` is the placement's JSON (below),
`alive` is how many of its NPCs are alive, and `waiting` says why it cannot spawn right now, or is null.

### `RunicNpc_SetPlacement(string id, JObject placement)` → `string`

Adds or replaces a persistent placement (D222). Null on success, or the reason. Replacing one despawns its NPCs and
spawns them again from the new values. Every set logs the cost warning (D227).

### `RunicNpc_RemovePlacement(string id)` → `bool`

Removes a placement and its NPCs.

### `RunicNpc_Routes()` → `JObject`

`{name: route, …}`.

### `RunicNpc_SetRoute(string name, JObject route)` → `string`

Adds or replaces a route (D234). Every point must be on Rust's navmesh. Null on success, or the reason.

### `RunicNpc_RemoveRoute(string name)` → `bool`

Removes a route. Placements that walk it wait until it exists again.

### `RunicNpc_IsRunicNpc(BaseEntity entity)` → `bool`

Whether `entity` is one of RunicNPC's NPCs.

### `RunicNpc_ProfileOf(BaseEntity entity)` → `string`

Its profile's name, or null.

### `RunicNpc_CostWarning(int adding)` → `string`

The cost warning (D227) for the NPCs the server plans, plus `adding`. It is built from stage 1's measurements
(PLAN.md §9), and says what the NPCs add to a server frame, idle and fighting, and how slowly each then reacts. A
caller that adds NPCs shows it to whoever added them.

---

## Hooks it raises

All are called on every plugin, and **none of them answers**: a return value is ignored.

| Hook | When |
|---|---|
| `OnRunicNpcSpawned(BasePlayer npc, string profile, string owner)` | After an NPC spawns and is equipped. |
| `OnRunicNpcHealth(BasePlayer npc, string profile, float threshold)` | The first time its health falls to one of the profile's `healthThresholds`. |
| `OnRunicNpcDied(BasePlayer npc, string profile, string owner, HitInfo info, Dictionary<ulong, float> contributors)` | When it dies. `contributors` maps each player's Steam id to the health that player took from it, the killing blow included, after Rust's protection. It never adds up to more than its health. |
| `OnRunicNpcDespawned(BasePlayer npc, string owner)` | When it is removed without dying. Not raised as RunicNPC itself unloads. |

---

## Data shapes

### A profile (D238)

```json
{
  "names": ["Warden", "Old Warden"],
  "kits": ["warden_rifle", "warden_smg"],
  "prefab": "scientistnpc_roam",
  "role": "roamer",
  "movement": { "mode": "wander", "radius": 20 },
  "health": 250,
  "damageDealt": 1.0,
  "damageTaken": { "head": 1.0, "body": 1.0, "legs": 1.0 },
  "aimCone": 2.0,
  "ranges": { "sense": 30, "loseTarget": 40, "chase": 40, "attack": 30 },
  "visionCone": -0.8,
  "sleepDistance": 160,
  "healthThresholds": [0.5]
}
```

| Field | Rule | Meaning |
|---|---|---|
| `names` | at least one | One is picked for each NPC. |
| `kits` | at least one; each must exist in Kits | One is picked for each NPC, and it is equipped with it (D217). |
| `prefab` | a Rust `scientistnpc_*` prefab that is a plain scientist | What it is built from. |
| `role` | `roamer` or `sentry` | A sentry never moves, and may stand off the navmesh. |
| `movement.mode` | `wander`, `monument` or `route:<name>` | D233. A placement may override it. |
| `movement.radius` | above 0 for `wander` | How far from home it wanders. |
| `health` | above 0 | Its health, and its maximum. |
| `damageDealt` | 0 or more | Multiplies its weapon's damage; 1 is the weapon's full damage. |
| `damageTaken` | each 0 or more | Multiplies the damage it takes to the head, the legs (legs and feet), and the body (everything else, including hits with no body part, like fire and explosions). |
| `aimCone` | 0 or more | How much its aim spreads; Rust's scientists use 2. |
| `ranges.sense` | above 0 | How far it notices players. |
| `ranges.loseTarget` | at least `sense` | How far a target must get before it is forgotten. |
| `ranges.chase` | 0 or more | How far from home it will chase (0: no limit). At that distance it waits 5 s for the target to come within range, then gives up and walks home. |
| `ranges.attack` | above 0 | How far it shoots from. This replaces the weapon's own range. |
| `visionCone` | −1 to 1 | Rust's vision cone. |
| `sleepDistance` | 0 or more | D235: with no player this close it walks home, then sleeps. 0: it never sleeps. |
| `healthThresholds` | fractions between 0 and 1 | Where `OnRunicNpcHealth` is raised. |

### A placement

```json
{
  "profile": "warden",
  "position": { "x": 100.0, "y": 12.5, "z": -340.0 },
  "yaw": 90,
  "count": 3,
  "respawn": 300,
  "respawnMode": "each",
  "movement": { "mode": "route:gate", "radius": 0 }
}
```

- `count` NPCs spawn at the spot, and all but the first are scattered within 3 m of it.
- `respawn` is in seconds, at least 1. `respawnMode` is `each` (every NPC returns `respawn` after its own death)
  or `group` (none returns until all are dead, then all return together) (D236).
- `movement` is optional and overrides the profile's.

### A route

```json
{ "points": [ { "x": 1, "y": 2, "z": 3 }, { "x": 4, "y": 2, "z": 6 } ], "loop": true }
```

At least two points, each on Rust's navmesh. With `loop`, the last point leads back to the first; without it, the
route is walked back and forth. An NPC joins the route at its nearest point.

---

## Files and config

- `data/RunicNPC/profiles.json` (`managed` and `profiles`), `placements.json` and `routes.json`, under `oxide/`
  or `carbon/`. On a standalone server profiles are edited in the file, then `rnpc.reload` reads them again. On a
  managed one the site pushes them.
- `config/RunicNPC.json`:
  - `caps`: `total`, `perOwner`, `perProfile` and `spawnsPerSecond`. **Each is 0, meaning no cap, until an admin
    sets it** (D227).
  - `spawnBudgetMs`: how many milliseconds of each server frame placements may spend spawning. The default is 8.
- `rnpc.status` at the console reports the swap's field check, the NPCs by owner and rest, profiles refused,
  placements waiting, the caps, and the cost warning.