Fixture Dev, LLC
Fixture builds focused, local-first developer tools for teams that ship with coding agents. Its products are designed to keep AI-written code tested, tracked, and trustworthy.
At a Glance
- Software developers and engineering teams
- Teams using AI coding agents
- Organizations that want local or CI-based software-quality checks
- Open-source developers and maintainers
AI Tools by Fixture Dev, LLC
(1)
Flawd
Mutation Testing for Developers
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Latest News
Fixture published 'We mutation-tested 10 popular open-source projects across five languages,' reporting verified results from 10 projects and describing Flawd's methodology.
Flawd 0.18.0 released with corrected targeted execution for Rust, container-setup fixes, and runner-override support.
Flawd 0.15.0 released with built-in upgrades, new-release notices, crash reports, and GitHub Action release-binary/checksum improvements.
Lash 0.5.0 released with prebuilt binaries and installer scripts for macOS, Windows, and Linux.
Products & Services
A local-first mutation-testing tool for the AI era. It plants realistic bugs in covered code, runs the existing tests in isolated containers, reports killed and surviving mutants, and generates Markdown handoffs with diffs, covering tests, and fix guidance for coding agents.
A free, open-source, terminal-first task management system that uses Markdown as the source of truth, with SQLite for speed, dependency-aware indexing, linting, search, a TUI, and agent integration. It is released under Apache-2.0.
A pragmatic shell for single-page apps, built on web components; listed by Fixture's GitHub organization as another project in the workshop.
Market Position
Fixture positions itself as a small, focused, local-first developer-tool company for the AI era. Flawd differentiates through multi-language mutation testing, coverage-driven and diff-scoped runs, container isolation, offline/local execution, and agent-readable handoffs rather than a cloud service; Lash differentiates through a Markdown-native, terminal-first task system for humans and coding agents.
Leadership
Founders
Frank O'Hara
Founder of Fixture; most recently a Staff Engineer at Slack, previously led test-infrastructure teams at Hulu, and has worked with startups. He first wired mutation testing into a CI pipeline in 2013.
Executive Team
Frank O'Hara
Founder
Staff Engineer at Slack before founding Fixture; previously led test-infrastructure teams at Hulu and worked with startups.
Founding Story
Frank O'Hara says Fixture grew out of a question he had pursued since first wiring mutation testing into CI in 2013: how do you know your tests would actually catch the bug? The company applies that question to the AI era, building local-first tools that test software quality and keep project work organized for humans and coding agents.
Business Model
Revenue Model
Flawd is sold through perpetual commercial licenses with 12 months of updates and support included; renewals are optional for another year of releases and support. Fixture says paid licenses are sold through Stripe. Lash is free and open source.
Pricing Tiers
Complete product, no feature/project/run limits, no credit card, one active evaluation machine.
One developer; unlimited projects and runs; local and CI use; 12 months of releases and support; eligible releases remain usable forever.
Company-owned transferable seats, one seat per developer, unlimited projects and runs, CI runners included, 12 months of releases and priority-queue support; published pricing covers 1–25 seats.
Target Markets
- Software developers and engineering teams
- Teams using AI coding agents
- Organizations that want local or CI-based software-quality checks
- Open-source developers and maintainers
- Validate whether AI-generated or human-written test suites catch realistic defects
- Run mutation testing locally during the development inner loop
- Gate pull requests and CI on mutation-score thresholds
- Hand surviving mutants to coding agents to write missing tests
- Manage developer and coding-agent tasks from a shared Markdown task list