jixu-core

jixu-core is the architectural center of Jixu. It defines the public Agent, Harness, Thread, Tool, Event, State, Effect, Driver, and Store contracts without importing provider SDKs, database drivers, or UI frameworks.

Install

npm install jixu-core

Create the core boundary

import {
  createHarness,
  defineAgent,
  InMemoryEventStore,
  type ModelDriver,
} from "jixu-core";

export function createAgentHarness(modelDriver: ModelDriver) {
  const agent = defineAgent({
    instructions: "Be precise and verify your work.",
    model: { provider: "model", model: "example-model" },
    modelCapabilities: {
      contextWindowTokens: 128_000,
      maxOutputTokens: 16_384,
      resolvedModel: "example-model",
      schemaVersion: 1,
      source: { kind: "explicit", name: "application-declaration" },
    },
    tools: [],
  });

  return createHarness({
    agent,
    modelDrivers: { model: modelDriver },
    store: new InMemoryEventStore(),
  });
}

Use jixu-llm for maintained model Drivers and a Store package when Thread history must survive a process restart.

Primary public surface

The normal application path stays small: define one Agent, create one Harness, then create or open Threads. Applications do not manually construct Events, invoke the Reducer, or dispatch Effects.

Harness and Thread

A Harness exposes createThread(), openThread(id), and listThreads(). A Thread exposes:

• send(input) and wait();
• state(), events(), and stream();
• clear(), interrupt(), pause(), and continue();
• setMode(mode);
• fork({ at, input }); and
• replay().

See Core model, Execution model, and Threads for the semantics behind this API.