Variable agentConst Experimental

Type Declaration

• • <
        const P extends AuthoredPurity
        | undefined = undefined,
        V extends ToolVocabulary = OpenToolVocabulary,
        Ok extends
            Readonly<Record<string, OutputFieldType>> = Readonly<
            Record<string, OutputFieldType>,
        >,
        Err extends
            Readonly<Record<string, OutputFieldType>> = Readonly<
            Record<string, OutputFieldType>,
        >,
    >(
        spec: AgentSpecInput<P, V, Ok, Err>,
    ): TypedAgentSpec<Ok, Err>
  • Experimental

    Define a subagent specification (compiles to agents/<name>.md).

    // agents/reviewer.md.spec.ts export default experimental_agent({ name: "reviewer", description: "Review a diff for correctness. Dispatch PROACTIVELY after edits.", model: "sonnet", tools: ["Read", "Grep", "Bash"], body: proseReview the diff. Run ${cmd("npm test")} first., rules: { "no-floating": enforce("@typescript-eslint/no-floating-promises", "Await promises."), }, });

    Generic over a tool Vocabulary (default OpenToolVocabulary — no constraint). A harness adapter re-exports a vocabulary-bound agent (e.g. vigiles/claude-code) so purity: "pure" + a side-effecting tool is a tsc error at edit time; the bare core experimental_agent() accepts any tools, as before.

    Also generic over the result's Ok/Err shapes, inferred from output: result(...). The returned value is a TypedAgentSpec<Ok, Err> — an AgentSpec that carries those shapes at the type level, so a typed pipe can cross-reference the handoff. With no output the shapes default to the erased Shape, and the value is still a plain AgentSpec — backwards-compatible.

    The SHAPE is not settled — the author is unsure of the design, which is exactly what this marker promises: the form may change. It is NOT a claim that the surface is unproven. Measured 2026-06-20: real Claude Code loaded a compiled agents/code-reviewer.md, dispatched to it and read it, 100% of trials — stronger end-to-end evidence than experimental_skill has.

    Type Parameters

    • const P extends AuthoredPurity | undefined = undefined
    • V extends ToolVocabulary = OpenToolVocabulary
    • Ok extends Readonly<Record<string, OutputFieldType>> = Readonly<Record<string, OutputFieldType>>
    • Err extends Readonly<Record<string, OutputFieldType>> = Readonly<Record<string, OutputFieldType>>

    Parameters

    • spec: AgentSpecInput<P, V, Ok, Err>

    Returns TypedAgentSpec<Ok, Err>

• andThen: <
      PriorOk extends Readonly<Record<string, OutputFieldType>>,
      PriorErr extends Readonly<Record<string, OutputFieldType>>,
      Needs extends Readonly<Record<string, OutputFieldType>>,
      Ok extends Readonly<Record<string, OutputFieldType>>,
      Err extends Readonly<Record<string, OutputFieldType>>,
  >(
      prior: Pipeline<PriorOk, PriorErr>,
      next: Supplies<PriorOk, Needs> extends true
          ? PipeStep<Needs, Ok, Err>
          : { __HANDOFF_ERROR: Supplies<PriorOk, Needs> },
  ) => Pipeline<Ok, PriorErr | Err>

• delegate: (
      agent: string,
      task?: string,
      needsContract?: Readonly<Record<string, OutputFieldType>>,
  ) => RailwayStep

• needs: <const N extends Readonly<Record<string, OutputFieldType>>>(shape: N) => N

• pipe: {
      <
          A extends Readonly<Record<string, OutputFieldType>>,
          AE extends Readonly<Record<string, OutputFieldType>>,
      >(
          a: TypedAgentSpec<A, AE>,
      ): Pipeline<A, AE>;
      <
          A extends Readonly<Record<string, OutputFieldType>>,
          AE extends Readonly<Record<string, OutputFieldType>>,
          BN extends Readonly<Record<string, OutputFieldType>>,
          B extends Readonly<Record<string, OutputFieldType>>,
          BE extends Readonly<Record<string, OutputFieldType>>,
      >(
          a: TypedAgentSpec<A, AE>,
          b: Supplies<A, BN> extends true
              ? PipeStep<BN, B, BE>
              : { __HANDOFF_ERROR: Supplies<A, BN> },
      ): Pipeline<B, AE | BE>;
      <
          A extends Readonly<Record<string, OutputFieldType>>,
          AE extends Readonly<Record<string, OutputFieldType>>,
          BN extends Readonly<Record<string, OutputFieldType>>,
          B extends Readonly<Record<string, OutputFieldType>>,
          BE extends Readonly<Record<string, OutputFieldType>>,
          CN extends Readonly<Record<string, OutputFieldType>>,
          C extends Readonly<Record<string, OutputFieldType>>,
          CE extends Readonly<Record<string, OutputFieldType>>,
      >(
          a: TypedAgentSpec<A, AE>,
          b: Supplies<A, BN> extends true
              ? PipeStep<BN, B, BE>
              : { __HANDOFF_ERROR: Supplies<A, BN> },
          c: Supplies<B, CN> extends true
              ? PipeStep<CN, C, CE>
              : { __HANDOFF_ERROR: Supplies<B, CN> },
      ): Pipeline<C, AE | BE | CE>;
      <
          A extends Readonly<Record<string, OutputFieldType>>,
          AE extends Readonly<Record<string, OutputFieldType>>,
          BN extends Readonly<Record<string, OutputFieldType>>,
          B extends Readonly<Record<string, OutputFieldType>>,
          BE extends Readonly<Record<string, OutputFieldType>>,
          CN extends Readonly<Record<string, OutputFieldType>>,
          C extends Readonly<Record<string, OutputFieldType>>,
          CE extends Readonly<Record<string, OutputFieldType>>,
          DN extends Readonly<Record<string, OutputFieldType>>,
          D extends Readonly<Record<string, OutputFieldType>>,
          DE extends Readonly<Record<string, OutputFieldType>>,
      >(
          a: TypedAgentSpec<A, AE>,
          b: Supplies<A, BN> extends true
              ? PipeStep<BN, B, BE>
              : { __HANDOFF_ERROR: Supplies<A, BN> },
          c: Supplies<B, CN> extends true
              ? PipeStep<CN, C, CE>
              : { __HANDOFF_ERROR: Supplies<B, CN> },
          d: Supplies<C, DN> extends true
              ? PipeStep<DN, D, DE>
              : { __HANDOFF_ERROR: Supplies<C, DN> },
      ): Pipeline<D, AE | BE | CE | DE>;
  }

• pipeStep: <
      Needs extends Readonly<Record<string, OutputFieldType>>,
      Ok extends Readonly<Record<string, OutputFieldType>>,
      Err extends Readonly<Record<string, OutputFieldType>>,
  >(
      a: TypedAgentSpec<Ok, Err>,
      needsContract?: Needs,
  ) => PipeStep<Needs, Ok, Err>

• railway: (spec: Omit<Railway, "_specType">) => Railway

• result: <
      const Ok extends Readonly<Record<string, OutputFieldType>>,
      const Err extends Readonly<Record<string, OutputFieldType>>,
  >(
      ok: Ok,
      err: Err,
  ) => OutputContract<Ok, Err>

• start: <
      Ok extends Readonly<Record<string, OutputFieldType>>,
      Err extends Readonly<Record<string, OutputFieldType>>,
  >(
      first:
          | PipeStep<Record<string, never>, Ok, Err>
          | TypedAgentSpec<Ok, Err>,
  ) => Pipeline<Ok, Err>