@klein-kit/core

One TypeScript SDK for every local coding agent. Drives the coding agents already installed and logged in on the machine — Codex, Claude Code, OpenCode, Cursor, and Pi — through a single, protocol-native session API. No API keys, no cloud proxy: each adapter spawns the user's own binary and inherits the machine's existing auth. Zero runtime dependencies.

import { createAgent, detectProviders } from "@klein-kit/core";

console.log(await detectProviders()); // what's installed + logged in

const session = await createAgent({
  provider: "codex",
  permissionMode: "ask",
  onPermissionRequest: async (req) => ({ behavior: "allow" }),
});

const turn = session.prompt("Fix the failing test in src/auth.ts");
for await (const event of turn) {
  if (event.type === "message.delta") process.stdout.write(event.text);
}
const { text, usage, filesChanged } = await turn;

• Protocol-native fidelity — checklists (a provider's plan or todo list, normalized to one checklist.updated event), tool calls with live output, file diffs, permission requests, reasoning streams, token/context usage, all as typed events with the untouched native payload on event.raw. Unclassifiable messages surface as unknown events, never dropped.
• Permissions — preset modes (read-only / ask / accept-edits / full-auto) plus a callback carrying the full native request.
• Sessions that survive restarts — session.nativeSessionId + resumeSession() use each backend's own persistence.
• Message queueing — prompting a busy session queues the turn; inspect and cancel via queuedTurns / cancelQueued.
• Capability matrix — session.capabilities tells you per provider what's native, emulated, or absent; session.raw() exposes the underlying protocol client.

Cross-agent orchestration (handoffs, reviewer loops, CI repair) lives in @klein-kit/orchestrate.

Full docs: github.com/yvescomputer/klein-kit · MIT © Yves Computer Company