From $49 per month🇺🇸
Prompt registry from New York for editing and versioning prompts without a code release, with evaluations and monitoring.
promptfoo overview and key facts (October 2026)
Open-source tool for testing prompts, models and RAG pipelines and for red teaming, usable in CI/CD, part of OpenAI since 2026.
Free
What is promptfoo?
promptfoo is an open-source command line tool and library for testing prompts, models and RAG pipelines and for red teaming AI applications. Developer teams use it to catch regressions and security issues before a change ships.
The CLI runs locally: test cases and assertions are written in YAML, results appear in a local viewer, and red-team scans cover more than 50 vulnerability types, including prompt injection, jailbreaks, PII leaks and business rule violations, for agents, RAG systems and integrations. The enterprise platform adds continuous monitoring. The repository is MIT-licensed and had about 25,500 stars with commits on September 28, 2026. promptfoo is now part of OpenAI; according to the README, the project remains open source under the MIT license.
promptfoo AI features and use cases
- Compares prompts and modelsTest cases run against several prompt versions and models, and assertions check the outputs. Teams pick the best combination based on repeatable results.
- Attacks your own applicationRed teaming generates adversarial inputs such as prompt injections and jailbreak attempts. Security gaps show up in testing, not in production.
- Guards every code changeThe tests run in CI/CD pipelines and post findings with remediation hints to pull requests. Regressions in prompts or RAG behavior are caught in review.
What sets promptfoo apart
- Combines prompt evaluation and security red teaming in one open-source tool.
- Runs locally and in CI without a hosted account.
- Owned by OpenAI since 2026 while remaining model-agnostic according to the project.
Where promptfoo is strongest
United States Available internationally
promptfoo is based in San Francisco and is now part of OpenAI.
Questions to ask before you buy promptfoo
promptfoo now belongs to OpenAI, so ask about roadmap, contracting entity and terms before planning long-term use of the enterprise platform. The MIT-licensed CLI remains usable independently. Scans call the models under test, which adds API cost and sends test prompts to those model providers.
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Questions about promptfoo
Is promptfoo free?
The CLI is open source under the MIT license and free. The enterprise platform is priced on request.
Who owns promptfoo?
promptfoo is part of OpenAI. It announced the move on March 9, 2026, and the README states that the project remains open source under the MIT license.
What can promptfoo test?
Prompts, models, agents and RAG systems, with evaluations and red-team scans for more than 50 vulnerability types.
promptfoo update historyno updates yet
No changes recorded for promptfoo yet.
Changes the vendor made and confirmed user reports, each checked against the vendor's own pages. We review every tool monthly.
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