Enum AgentKind 

pub enum AgentKind {
    Lua,
    RustFn,
    AgentBlock,
    Subprocess,
    Operator,
}

SoT of the Worker IMPL axis. A closed enum managed inside Swarm and extended by variant addition through explicit maintenance. String lookup / escape hatches are deliberately not adopted.

This enum expresses Worker IMPL directly; dispatching to a host Spawner adapter is resolved by an internal Resolver on the compiler side (= callers see only the Worker IMPL viewpoint).

Internal Resolver mapping (= currently a fixed 1:1, carry: priority list form)

AgentKind	Host Spawner adapter
Lua	InProcSpawner (mlua VM eval)
RustFn	InProcSpawner (Rust closure)
AgentBlock	InProcSpawner (agent-block-core SDK in-process)
Subprocess	ProcessSpawner (child process launch)
Operator	OperatorSpawner (interactive role / Human-MainAI delegation)

Variants

Lua

Lua script eval through the mlua VM (= factory-side registry looked up by spec.fn_id).

RustFn

Rust closure (= factory-side registry looked up by spec.fn_id).

AgentBlock

Headless LLM agent via the agent-block-core SDK (in-process).

Pairs with a Runner::AgentBlockInProcess. Its spec contract (GH #86 — every key optional):

key	meaning
script_path	Absent → PromptBasedAgent mode (the host embeds an invoker that calls the SDK’s agent module). Present → ScriptBasedAgent mode (that Lua script runs instead).
project_root	Compile-time fallback cwd. Overridden per launch by init_ctx.work_dir / init_ctx.project_root.
mcp_rpc_timeout_ms	MCP RPC timeout; default 30000.
mcp_servers	[{name, command, args}] pool the tool grant selects from.

The step’s evaluated in reaches the agent as the _PROMPT Lua global and profile.system_prompt as _CONTEXT — not through the server process env. A script returns its result by calling bus.emit(<kind>, payload); the host reads payload.content, else payload.response, else the whole payload, as the step OUTPUT body (which is what a VerdictChannel::Body contract compares).

Subprocess

Child-process launch (= spec.program + args, via the ProcessSpawner path).

Operator

Interactive Operator role (= MainAI / Human delegation, spec.operator_ref).

Trait Implementations

impl Clone for AgentKind

fn clone(&self) -> AgentKind

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AgentKind

fn fmt(&self, f: &mut Formatter<'_>) -> Result<(), Error>

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for AgentKind

fn deserialize<__D>( __deserializer: __D, ) -> Result<AgentKind, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Eq for AgentKind

impl Hash for AgentKind

fn hash<__H>(&self, state: &mut __H)

where __H: Hasher,

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl JsonSchema for AgentKind

fn schema_name() -> Cow<'static, str>

The name of the generated JSON Schema.

fn schema_id() -> Cow<'static, str>

Returns a string that uniquely identifies the schema produced by this type.

fn json_schema(generator: &mut SchemaGenerator) -> Schema

Generates a JSON Schema for this type.

fn inline_schema() -> bool

Whether JSON Schemas generated for this type should be included directly in parent schemas, rather than being re-used where possible using the $ref keyword.

impl PartialEq for AgentKind

fn eq(&self, other: &AgentKind) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl Serialize for AgentKind

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.

impl StructuralPartialEq for AgentKind