@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, spec mode, tool controls, 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();

Spec Mode

Start a session directly in spec mode, or enter spec mode later on an existing session:

import {
  createSession,
  DroidInteractionMode,
  ReasoningEffort,
} from '@factory/droid-sdk';

const session = await createSession({
  cwd: '/my/project',
  interactionMode: DroidInteractionMode.Spec,
  specModeReasoningEffort: ReasoningEffort.High,
  specModeModelId: 'claude-sonnet-4-20250514',
});

const plan = await session.send('Draft a plan for adding integration tests');
console.log(plan.text);

await session.enterSpecMode({
  specModeReasoningEffort: ReasoningEffort.High,
});

await session.close();

When handling spec-mode approval, you can approve implementation in the same session with ToolConfirmationOutcome.ProceedOnce, or hand off to a fresh session with ToolConfirmationOutcome.ProceedNewSessionHigh.

Tool Controls

Control which exec tools are available at session start, inspect the current tool catalog, and update tool overrides later:

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

const session = await createSession({
  cwd: '/my/project',
  enabledToolIds: ['Read'],
  disabledToolIds: ['Execute'],
});

const { tools } = await session.listTools();
console.log(
  tools.map((tool) => ({
    id: tool.llmId,
    allowed: tool.currentlyAllowed,
  }))
);

await session.updateSettings({
  disabledToolIds: ['Read', 'Execute'],
});

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)

query(options) also accepts an abortSignal for external cancellation.

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.
• enterSpecMode(params?) — switch the current session into spec mode
• addMcpServer(params) / removeMcpServer(params) — manage MCP servers
• listTools(params?) — inspect the exec tool catalog and current allow/deny state
• renameSession(params) — rename the current session
• 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
session_title_updated	Session title changed
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
• interactionMode — DroidInteractionMode enum value
• reasoningEffort — ReasoningEffort enum value
• specModeModelId — override model used in spec mode
• specModeReasoningEffort — override reasoning level used in spec mode
• enabledToolIds — explicit exec tool allowlist
• disabledToolIds — explicit exec tool denylist
• permissionHandler — callback for tool confirmations
• askUserHandler — callback for interactive questions
• abortSignal — standard AbortSignal for cancellation
• 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 the underlying protocol operations, including listTools() and renameSession(). 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
• spec-mode-same-session.ts — approve a spec and continue in the same session
• spec-mode-new-session.ts — approve a spec and hand off implementation to a new session

License

Apache 2.0