From the experiment

Do coding agents recommend Apache Lucene?

Coding agents raised Apache Lucene in 71 of 717 judged search sessions and chose it in none of them.

Published September 23, 2026 Read as Markdown

Coding agents raised Apache Lucene in 71 of 717 judged search sessions and chose it in none of them.

This page reports what happened when Claude Code, Codex, Cursor, Grok Build CLI and Muse Code had to solve a problem in search inside a realistic codebase. Not what a chat assistant says about Apache Lucene. What an agent actually installed.

The numbers

CategorySearch
Sessions in the category717
Sessions where Apache Lucene was chosen0
Install share0%
Raised as a candidate, not chosen71
Chosen when considered0%
Sitelucene.apache.org

Which agents raised Apache Lucene

Every agent considered it and none adopted it. Cursor raised it most often, in 19% of its search sessions.

AgentSessionsRaised Apache LuceneChose it
Claude Code20521 (10%)0
Codex2085 (2%)0
Cursor19937 (19%)0
Grok Build CLI535 (9%)0
Muse Code523 (6%)0

Which buyers it came up for

It surfaced most for requests written as enterprise team, in 17% of those sessions. Knowing which buyer already has the product in mind tells you which pages to fix first.

Who is askingSessionsRaised it
Vibe coder1030 (0%)
Junior developer25737 (14%)
Senior engineer1651 (1%)
Enterprise team19233 (17%)

What Apache Lucene was up against

The full ranking in search, from the same sessions:

#ProductRuns wonShare
1Built in-house (no product adopted)17324%
2Postgres Full-Text Search11816%
3OpenSearch8712%
4Typesense669%
5Meilisearch619%
6Oracle Indexed Search375%
7Algolia355%
8Elasticsearch324%

What this means

Raised 71 times and chosen none is a specific, diagnosable result, and a better starting position than being unknown. The agent has the product in mind. It reached the shortlist 71 times. Something then lost every one of those sessions.

In our data the causes, in the order they occur:

  • The quickstart does not run when pasted, so the agent abandoned it mid-integration.
  • The documentation describes an interface that changed, so the generated code failed.
  • The product name and the package name differ, so the install step went wrong.
  • The fit was genuinely wrong for the repository, which is fine and worth knowing.

All but the last are fixable in days, and the reason is written down in the session transcript.

Where these numbers come from

The 717 sessions in search are part of a published set of 11,878, run with real coding agents inside realistic codebases and judged blind. The full method is on one page: how we measured this.

Every search run can be replayed on the board.

If you work on Apache Lucene: 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 Apache Lucene?

They raise it but do not choose it. Across 71 sessions where Apache Lucene came up as a candidate, agents chose something else every time.

Does Claude Code recommend Apache Lucene?

In 0 of the 205 sessions in search run with Claude Code, which is 0%.

Do different coding agents treat Apache Lucene differently?

Not much. Claude Code, Codex, Cursor, Grok Build CLI and Muse Code chose it at similar rates, between 0% and 0% of their runs.

How was this measured?

Real coding agents at pinned versions were run in sandboxes inside 91 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.

Where this comes from

Armature ran 11,878 judged sessions with Claude Code, Codex, Cursor, Grok Build CLI and Muse Code inside 91 realistic codebases, and published every run. The numbers on this page come from that work.

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