> ## Documentation Index > Fetch the complete documentation index at: https://docs.eucaengine.com/llms.txt > Use this file to discover all available pages before exploring further. # Units & roles > Compose a playable unit — health, team, auto-combat, gold, and a role label — from genre-neutral gameplay components in one spawn call, then read back exactly the components it stamped. Built end to end on a local server. A "hero" in Euca is not a special type — it is a **generic entity composed from gameplay components**. You spawn it with flags that map one-to-one onto components: `health`→`Health`, `team`→`Team`, `combat`→an `AutoCombat` bundle, `gold`/`gold_bounty`/`xp_bounty`→the economy components, and `role` is a label (`EntityRole::Hero`). One `POST /spawn` stamps the whole bundle. This builds on the genre-neutral [gameplay](/systems/gameplay-and-combat) primitives; every command is real and runnable against a [local server](/quickstart), with output captured from one. The full Dota-style hero kit (mana, abilities, base/growth stats) is assembled by the **MOBA example game** (`games/euca-moba`), not by the generic HTTP surface — see [MOBA systems](/systems/moba). ## Compose a unit **Spawn an entity with gameplay components.** The flat keys on `/spawn` each add a component; omit one and that component is left off. This is exactly what the CLI front-end `euca entity create --role hero --combat --gold …` sends. ```bash theme={null} curl -s -X POST http://localhost:3917/spawn -H 'Content-Type: application/json' -d '{ "mesh":"sphere","color":"cyan","position":[-7,0.5,0],"health":500,"team":1, "combat":true,"combat_damage":30,"combat_range":2,"combat_speed":4,"combat_cooldown":0.8, "role":"hero","gold":600,"gold_bounty":300,"xp_bounty":200}' # {"entity_id":103,"entity_generation":0} ``` The same call over the CLI: ```bash theme={null} euca entity create --mesh sphere --color cyan "--position=-7,0.5,0" \ --health 500 --team 1 --combat --combat-damage 30 --combat-range 2 \ --combat-speed 4 --combat-cooldown 0.8 --role hero \ --gold 600 --gold-bounty 300 --xp-bounty 200 ``` **Read the entity back.** `/entities/{id}` shows precisely the components the flags stamped on — `Health`, `Team`, `Gold`, a `Level(1)` (added alongside gold), and `EntityRole::Hero`. There is **no** mana, ability set, or base/growth stats: those are the MOBA game's hero kit, not the generic spawn. ```bash theme={null} curl -s http://localhost:3917/entities/103 # {"id":103,"generation":0, # "transform":{"position":[0.0,0.0,0.0], ...}, # "velocity":{"linear":[0.0,0.0,0.0],"angular":[0.0,0.0,0.0]}, # "health":[500.0,500.0],"team":1,"gold":600,"level":1,"role":"Hero"} ``` After one `/step`, the transform propagates to the spawn `position`: ```bash theme={null} curl -s -X POST http://localhost:3917/step -H 'Content-Type: application/json' -d '{"ticks":1}' curl -s http://localhost:3917/entities/103 # {..., "transform":{"position":[-7.0,0.5,0.0], ...}, "health":[500.0,500.0], "role":"Hero"} ``` ## What each flag maps to | Flag (spawn key / CLI) | Component(s) added | | ------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------ | | `health` / `--health` | `Health(current, max)` | | `team` / `--team` | `Team` | | `combat` (+ `combat_damage`/`combat_range`/`combat_speed`/`combat_cooldown`/`combat_style`) | an `AutoCombat` bundle (detect → chase → attack), plus `Velocity` for movement | | `gold` / `--gold` | `Gold` **and** `Level(1)` | | `gold_bounty` / `--gold-bounty`, `xp_bounty` / `--xp-bounty` | `GoldBounty` / `XpBounty` (paid to the killer) | | `role` / `--role` (`hero`/`minion`/`tower`/`structure`) | `EntityRole` label | | `player` / `--player` | `PlayerHero` marker | | `spawn_point` / `--spawn-point` | marks a team respawn location | ## Behavior and gotchas The things you only learn by running it: * **A unit is just components — there is no hero registry or template.** The deleted `/hero/define`, `/hero/select`, and `/hero/list` routes are gone (they 404). You compose a unit per-spawn from the flags above; re-create it with different flags to change it. * **`gold` adds `Level(1)`, not just `Gold`.** Spawning with `gold` also stamps a `Level(1)` so leveling and bounties have something to read; you get `"level":1` back even though you passed only `gold`. * **`combat` needs its sub-flags to be useful.** `combat:true` alone enables the auto-combat behavior but with default numbers; pass `combat_damage`/`combat_range`/`combat_cooldown` (and `combat_speed:0` for a stationary tower) to tune it. See [Gameplay & combat](/systems/gameplay-and-combat). * **`transform.position` is `[0,0,0]` until the first `/step`.** The component state is correct immediately; the transform is just unpropagated until the tick loop runs — see [Simulation](/systems/simulation). * **Mana, abilities, and stat growth are the MOBA game's hero kit.** They are inserted in Rust by `euca-moba`'s `spawn_hero`, not by `/spawn`. There is no generic HTTP route that attaches an `AbilitySet` — see [Abilities & status effects](/systems/abilities-and-status-effects). ## Endpoints | Method | Path | Description | | ------ | --------------------------- | ----------------------------------------------------------- | | `POST` | `/spawn` | Create an entity, composing components from the flags above | | `GET` | `/entities/{id}` | Read back the entity with all its components | | `POST` | `/entities/{id}/components` | Add/update components on an existing entity | The combat, economy, and team primitives a unit is built from live on [Gameplay & combat](/systems/gameplay-and-combat); items and the gold economy are on [Inventory & economy](/systems/inventory-and-economy). ## Status * **Shipped, all headless** — composing a unit from gameplay components in one spawn call (health, team, auto-combat, gold + level, bounties, role), with read-back of exactly the stamped components. * **MOBA hero kit** (mana, abilities, base/growth stats) ships in the [MOBA example game](/systems/moba), assembled in-engine rather than over the generic HTTP surface. The spawn and entity endpoints, with request and response schemas.