Do coding agents recommend Promptfoo?
Promptfoo was chosen in 15% of 478 judged evals sessions, ranking second. Measured with Claude Code, Codex, Cursor, Grok Build CLI and Muse Code.
Promptfoo was chosen in 15% of 478 judged evals sessions, ranking second. It was also raised as a candidate in 132 further sessions without being chosen.
This page reports what happened when Claude Code, Codex, Cursor, Grok Build CLI and Muse Code had to solve a problem in evals inside a realistic codebase. Not what a chat assistant says about Promptfoo. What an agent actually installed.
The numbers
| Category | Evals |
| Sessions in the category | 478 |
| Sessions where Promptfoo was chosen | 70 |
| Install share | 15% |
| Rank in category | 2 of 11 |
| Codebases it won in | 2 |
| Raised as a candidate, not chosen | 132 |
| Chosen when considered | 35% |
| Site | promptfoo.dev |
By agent
Claude Code, Codex, Cursor and Muse Code land within 8 points of each other on Promptfoo, which is closer than most products in this experiment manage. Grok Build CLI ran fewer than 30 sessions here, too few to compare.
| Agent | Sessions | Chose Promptfoo | Share |
|---|---|---|---|
| Claude Code | 120 | 22 | 18% |
| Codex | 144 | 17 | 12% |
| Cursor | 120 | 19 | 16% |
| Grok Build CLI | 22 | 5 | 23% |
| Muse Code | 72 | 7 | 10% |
By who was asking
Promptfoo does much better with one kind of buyer than another. It won 25% of sessions asked as senior engineer and 5% of those asked as junior developer.
| Who is asking | Sessions | Chose Promptfoo | Share |
|---|---|---|---|
| Junior developer | 241 | 11 | 5% |
| Senior engineer | 237 | 59 | 25% |
What Promptfoo was up against
The full ranking in evals, from the same sessions:
| # | Product | Runs won | Share |
|---|---|---|---|
| 1 | Built in-house (no product adopted) | 161 | 34% |
| 2 | Langfuse | 148 | 31% |
| 3 | Promptfoo (this page) | 70 | 15% |
| 4 | Arize Phoenix | 32 | 7% |
| 5 | Braintrust | 23 | 5% |
| 6 | Inspect AI | 16 | 3% |
| 7 | Helicone | 12 | 3% |
| 8 | LangSmith | 9 | 2% |
What this means
A solid second or third position in a category means the agent is genuinely choosing rather than reaching automatically. That is a winnable position, because the inputs it uses can be changed.
The fastest gains are usually in the sessions that were nearly won: read them, find the step where the agent moved on, and fix that step.
Where these numbers come from
The 478 sessions in evals are part of a published set of 15,287, run with real coding agents inside realistic codebases and judged blind. The full method is on one page: how we measured this.
Every evals run can be replayed on the board.
If you work on Promptfoo: the judge recorded a reason for every session where it was raised and passed over. Those reasons are in the transcripts.
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Common questions
Do coding agents recommend Promptfoo?
Yes. Promptfoo was chosen in 70 of the 478 judged sessions in evals, a 15% install share, ranking second in its category.
Does Claude Code recommend Promptfoo?
In 22 of the 120 sessions in evals run with Claude Code, which is 18%.
Do different coding agents treat Promptfoo differently?
Not much. Claude Code, Codex, Cursor and Muse Code chose it at similar rates, between 10% and 18% of their runs.
How was this measured?
Real coding agents at pinned versions were run in sandboxes inside 110 realistic codebases and asked to solve real tasks. A simulated project owner approved or questioned each recommendation before any code was written, and a judge from a model family that builds none of the agents read every session blind.
How often is Promptfoo considered but not chosen?
It was raised as a candidate in 132 sessions without being chosen, and chosen in 70. That is a 35% conversion from considered to chosen.
Where this comes from
Armature ran 15,287 judged sessions with Claude Code, Codex, Cursor, Grok Build CLI and Muse Code inside 110 realistic codebases, and published every run. The numbers on this page come from that work.