@factory/droid-sdk

TypeScript SDK for the Factory Droid CLI. Provides a high-level API for interacting with Droid as a subprocess, with streaming message support, multi-turn sessions, and tool permission handling.

Requirements

• Node.js 18+
• The droid CLI installed and available on your PATH

Installation

npm install @factory/droid-sdk

Quick Start

Send a one-shot prompt and stream the response:

import { query } from "@factory/droid-sdk";

const stream = query({
  prompt: "What files are in the current directory?",
  cwd: "/my/project",
});

for await (const msg of stream) {
  if (msg.type === "assistant_text_delta") {
    process.stdout.write(msg.text);
  }
  if (msg.type === "turn_complete") {
    console.log("\nDone!");
  }
}

Multi-Turn Sessions

Use createSession() for persistent conversations with multiple turns:

import { createSession } from "@factory/droid-sdk";

const session = await createSession({ cwd: "/my/project" });

// Streaming turn
for await (const msg of session.stream("List all TypeScript files")) {
  if (msg.type === "assistant_text_delta") {
    process.stdout.write(msg.text);
  }
}

// Non-streaming turn
const result = await session.send("Summarize the project");
console.log(result.text);

await session.close();

Resume an existing session by ID:

import { resumeSession } from "@factory/droid-sdk";

const session = await resumeSession("session-id-here");
const result = await session.send("Continue where we left off");
console.log(result.text);
await session.close();

Permission Handling

Handle tool confirmation requests with a custom permission handler:

import { query, ToolConfirmationOutcome } from "@factory/droid-sdk";

const stream = query({
  prompt: "Create a hello.txt file",
  cwd: "/my/project",
  permissionHandler(params) {
    console.log("Tool permission requested:", params);
    return ToolConfirmationOutcome.ProceedOnce;
  },
});

for await (const msg of stream) {
  if (msg.type === "assistant_text_delta") {
    process.stdout.write(msg.text);
  }
}

API Reference

Top-Level Functions

Function	Description
query(options)	One-shot prompt → async generator of DroidMessage events
createSession(options?)	Create a new multi-turn session → DroidSession
resumeSession(id, options?)	Resume an existing session → DroidSession

query(options): DroidQuery

Returns an async generator that yields DroidMessage events. The returned DroidQuery object also exposes:

• interrupt() — gracefully interrupt the agent's current turn
• abort() — forcefully kill the subprocess
• sessionId — the session ID (available after initialization)

DroidSession

Returned by createSession() and resumeSession(). Key methods:

• stream(text, options?) — send a message, returns async generator of DroidMessage
• send(text, options?) — send a message, returns aggregated DroidResult
• interrupt() — interrupt the current turn
• close() — close the session and release resources
• updateSettings(params) — update model, autonomy level, etc.
• addMcpServer(params) / removeMcpServer(params) — manage MCP servers
• sessionId — the session ID

DroidResult

Returned by session.send():

• text — concatenated assistant response text
• messages — all DroidMessage objects from the turn
• tokenUsage — final token usage, or null

DroidMessage Types

All messages have a discriminated type field:

Type	Description
assistant_text_delta	Streaming text token from the assistant
thinking_text_delta	Streaming reasoning/thinking token
tool_use	Tool invocation by the assistant
tool_result	Result from a tool execution
tool_progress	Progress update during tool execution
working_state_changed	Agent working state transition
token_usage_update	Updated token usage counters
create_message	Full assistant message created
turn_complete	Sentinel: agent turn finished
error	Error event from the process

Options

QueryOptions and CreateSessionOptions accept:

• prompt — the user prompt (query only)
• cwd — working directory for the session
• modelId — LLM model identifier
• autonomyLevel — AutonomyLevel enum value
• reasoningEffort — ReasoningEffort enum value
• permissionHandler — callback for tool confirmations
• askUserHandler — callback for interactive questions
• execPath — path to droid executable (default: "droid")
• transport — provide a custom transport instead of spawning a process

DroidClient

Low-level JSON-RPC client for advanced use. Provides typed methods for all 19 protocol operations. Most users should prefer query() and createSession().

Error Types

Error	Description
ConnectionError	Failed to connect to the droid process
ProtocolError	JSON-RPC protocol error
SessionError	Base session error
SessionNotFoundError	Session ID not found
TimeoutError	Request timed out
ProcessExitError	Droid subprocess exited unexpectedly

Examples

See the examples/ directory for runnable examples:

• simple-query.ts — one-shot query with streaming output
• multi-turn-session.ts — multi-turn session lifecycle
• permission-handler.ts — custom permission handling

License

Apache 2.0