How to use Claude to port JSONata to Go
Claude Code and Codex helped replace an older JSONata Go port with a version 2.0.6 implementation that reportedly passed the full test set and was deployed in Blues' Notehub.
news.ycombinator.com
Suggested prompt
Suggested prompt written by Agents In Use, not the source author. Replace bracketed inputs and review tool permissions first.
Port [source implementation and version] to Go while preserving its language semantics. Use [conformance suite] to check compatibility, investigate recursion failures, and provide an exerciser that can switch between [old implementation] and the new port.
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See placements →Evidence at a glance
Sourced account- Source poster / publisher
- rozzie
- Original account
- Read the source ↗
- Published
- Source link checked
- Reported result
- The author reports a JSONata 2.0.6 Go port passing the full test set, a comparison exerciser and a seamless migration to production use in Blues' Notehub.
- Human involvement
- The author reports full test-suite conformance and a production migration, but does not describe individual code reviews.
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How the agent did it
- Use Claude Code and Codex to develop a compliant JSONata Go port.
- Run the port against the full JSONata test set.
- Publish the port with an exerciser that switches implementations.
The author describes replacing an older Go implementation of JSONata with a new port developed using Claude Code and Codex. The earlier implementation had been commissioned from an Upwork contractor and was based on version 1.5.3. Although it had served the company, it failed most of the JavaScript test suite and had recursion bugs that could cause segmentation faults with problematic expressions.
Early in 2025, the author used the two coding agents to produce a compliant port. They emphasize that the work was difficult because JSONata syntax contains nuances inherited from JavaScript. The resulting version 2.0.6 implementation reportedly passed the full test set.
The published result also included a Go exerciser that allowed switching between implementations. The team then migrated Blues' Notehub, where JSONata provides customer transformations in a JSON message pipeline. The author describes the migration as seamless and says the replacement had been running successfully in production for some time. The excerpt does not attribute individual implementation tasks to either agent.
Who it's for: Developers replacing a language implementation with compatibility requirements.
Prompt
Suggested prompt (written by Agents In Use, not the author's)
Source: Hacker News · rozzie
Frequently asked questions
Were both Claude Code and Codex involved?
Yes. The author explicitly names both tools, but does not describe which portions of the port each one handled.
What verification and deployment results were reported?
The author reports passing the full test set, publishing an exerciser for switching implementations and completing a seamless migration in Blues' Notehub.
More details
Remaining steps
- Migrate Notehub's JSON transformation capability to the new implementation.
About this account
The agents assisted with a difficult compatibility port; the source does not describe their task allocation or unattended execution.
Platform: Hacker News. Attribution: https://news.ycombinator.com/item?id=47538918. Prompt: Suggested (written by Agents In Use, not the author's). Sourced by the Agents In Use pipeline.
Credit: rozzie on Hacker News
Source published
Added to Agents In Use
Source checked
Tools and topics
Claude Code · Codex · JSONata test suite · Go exerciser
Go · Language porting · JSONata · Compatibility
Editorial completeness: 100/100. Measures documented fields, not agent performance or verified outcomes.