Meet Factory Droid 1.0: A Model-Independent Coding Agent Harness Built on Script Mode

Factory has released Droid 1.0, the largest update yet to the Factory Droid agent harness.

The main change is programmatic tool calling, now on by default.

The model writes a program that runs its tools.

One model request can now drive hundreds of tool calls.

TL;DR Size: Base prompt is 13,055 input tokens, down 37% from 20,887.

Only 2 tool definitions ship up front, down from 11.

Runs on: macOS and Windows desktop app, a terminal UI, and the Node SDK @factory/droid-sdk.

Works with any supported model, including your own API keys.

Performance: Highest pass rate of every harness Factory tested, on the same model, at lower cost.

Best: 65.2% on Terminal-Bench 4 with Claude Opus 5.5, at $4.73 per passed task (self-reported).

Worst: With GPT-6.1 Sol, Droid takes 10% longer per passed task than Codex.

What is Droid 1.0?

Droid 1.0 is a model-independent coding agent harness from Factory.

Factory defines a harness as everything around the model.

That means the prompts, the tools, how tool results return, and the loop.

Users pick a model or let Factory Router choose a cost-efficient mix.

How does programmatic tool calling work?

In a standard loop, every tool output lands in the model’s context.

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