# Factory launches Droid 1.0, a coding agent harness using programmatic tool calling

> Original title: Droid 1.0: Building a Frontier Harness

- Source: Factory News
- Published: 2026-10-29T00:00:00.000Z
- Bad Influence: https://badinfluence.news/items/nt88worl4lrnui1ljn1e257rs
- Original: https://factory.com/news/frontier-harness

## Summary

Factory releases Droid 1.0, an agent harness that runs model-written JavaScript programs to make tool calls. In Terminal-Bench 4 tests, Factory says Droid scores higher than the compared harnesses at lower cost on the same models. Its Script mode cut Droid's cost by 15% on Claude Opus 5.5, and the company reports faster app startup and a 37% smaller base prompt.

## Why it matters

The post explains how programmatic tool calling and cache-aware prompt changes reduce cost and latency in a coding agent harness, with per-model benchmark and production figures.