From the experiment

Do coding agents recommend Apache Pulsar?

Coding agents raised Apache Pulsar in 73 of 636 judged message queues sessions and chose it in none of them.

Published September 28, 2026 Updated September 29, 2026 Read as Markdown

Coding agents raised Apache Pulsar in 73 of 636 judged message queues 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 message queues inside a realistic codebase. Not what a chat assistant says about Apache Pulsar. What an agent actually installed.

The numbers

CategoryMessage queues
Sessions in the category636
Sessions where Apache Pulsar was chosen0
Install share0%
Raised as a candidate, not chosen73
Chosen when considered0%
Sitepulsar.apache.org

Which agents raised Apache Pulsar

Every agent considered it and none adopted it. Cursor raised it most often, in 20% of its message queues sessions.

AgentSessionsRaised Apache PulsarChose it
Claude Code13813 (9%)0
Codex19222 (11%)0
Cursor13427 (20%)0
Grok Build CLI354 (11%)0
Muse Code1377 (5%)0

Which buyers it came up for

It surfaced most for requests written as enterprise team, in 23% of those sessions. Knowing which buyer already has the product in mind tells you which pages to fix first.

Who is askingSessionsRaised it
Vibe coder1040 (0%)
Junior developer20717 (8%)
Senior engineer1075 (5%)
Enterprise team21851 (23%)

What Apache Pulsar was up against

The full ranking in message queues, from the same sessions:

#ProductRuns wonShare
1Built in-house (no product adopted)10617%
2Apache Kafka8313%
3Amazon SQS7211%
4Service Bus538%
5Amazon Kinesis457%
6Laravel Queues437%
7Cloud Tasks406%
8Cloudflare Queues356%

What this means

Raised 73 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 73 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 636 sessions in message queues are part of a published set of 15,051, run with real coding agents inside realistic codebases and judged blind. The full method is on one page: how we measured this.

Every message queues run can be replayed on the board.

If you work on Apache Pulsar: 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 Pulsar?

They raise it but do not choose it. Across 73 sessions where Apache Pulsar came up as a candidate, agents chose something else every time.

Does Claude Code recommend Apache Pulsar?

In 0 of the 138 sessions in message queues run with Claude Code, which is 0%.

Do different coding agents treat Apache Pulsar 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 92 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 15,051 judged sessions with Claude Code, Codex, Cursor, Grok Build CLI and Muse Code inside 92 realistic codebases, and published every run. The numbers on this page come from that work.

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