Which AI tools do people use to port code to another language?

Across the 9 sourced use cases in this guide, the most used tools are Claude Code, OpenAI Codex, Rust, Claude Opus 5.5, Claude Sonnet 5.5.

How much does it cost to get started?

1 of the 9 use cases can start on a free plan. The most common paid starting price is $17/mo (7 use cases). Prices come from each tool's official pricing page.

How long does setup take?

1 of the 9 use cases lists a setup time of an hour or less. Each card shows the setup time the builder reported.

Are these real examples?

Yes. Every use case links to its public source (an X post, a Hacker News thread or a GitHub repo) with the author and date, so you can check it yourself.

How to port code to another language with AI

Short answer: Give a coding agent such as Claude Code or Codex the whole job plus a test suite that defines correct behavior, then let it loop: port, run the tests, fix, run again. The examples below include a C server moved to Rust in 9.5 hours, 700K lines of COBOL migrated with outputs compared side by side in Java, a backend moved from .NET to Hono in 36 days and 24 files converted to TypeScript for $0.71 by a swarm of small agents. Write or capture tests before you start, port in small units, and run the old and new versions on the same inputs before you switch over.

How teams moved real codebases to Rust, Swift, Java and TypeScript with coding agents, and what kept the ports honest: tests, side-by-side runs and small units of work. 9 matching use cases below, each with a public source.

Looking for something else? Search all 1448 use cases or .

Get started in 3 steps

Capture the current behavior first: existing tests, recorded inputs and outputs, and the business rules hidden in the code.
Split the port into small units (one file, module or route per agent) and use a cheaper model for the bulk with a stronger model for planning and merging.
Run the old and new versions side by side on the same inputs and only switch over when the outputs match and the test suite passes.

Vibe coding & appsX · @virtual_amir

Port a Vision Pro sports game's AI engine with Codex

A developer built MatchCore, the game-intelligence engine for his Toybox Soccer game on Apple Vision Pro, tuned with thousands of 2D simulations and trials of over 20 hand-controller designs. He then asked Codex to port the engine overnight.

Free tierWeeksAdvanced

OpenAI Codex Apple Vision Pro

Dev & opsX · @spreen_co

Port Codex's computer-use feature to Rust so Claude Code and any agent can use it

He reverse-engineered the computer-use component that ships with the open-source Codex and rebuilt it in Rust so Claude Code and other agents can use it.

$17/moDaysAdvanced

OpenAI Codex Claude Code Rust

Dev & opsX · @0X_Vetra

Convert a codebase to TypeScript with a swarm of cheap agents

A shared Claude Code recipe uses Sonnet 5.5 as the lead and a swarm of Haiku 5.5 agents that each convert one file to TypeScript. The hardest files go to Sonnet, which then merges every diff and runs the test suite.

$17/mo15 minutesIntermediate

Claude Code Claude Sonnet 5.5 Claude Haiku 5.5

Dev & opsX · @stretchcloud

Move a production backend from .NET to Hono without typing code by hand

A published case study follows a developer who moved a financial platform's backend from .NET to Hono in 36 days using Claude Code, Cursor and Codex together.

$17/moWeeksAdvanced

Claude Code Cursor OpenAI Codex

Vibe coding & appsX · @zathvarun

Design a device UI with ChatGPT sprites and port it to LVGL with agents

A hardware builder made the screens and sprites for his Capy device in ChatGPT, exported a transparent sprite sheet so nothing had to be cut out by hand, and had Codex and Claude Code slice the art and port the UI to the LVGL embedded graphics library.

$17/mo1 dayIntermediate

ChatGPT OpenAI Codex Claude Code

Dev & opsX · @0xShoopy

Migrate legacy COBOL to Java with agents and prove the outputs match

In a 50-minute live demo, Anthropic's Claude Code team migrated legacy code with agents: Opus 5.5 moved about 700K lines in under a day, pulled 323 business rules out of 44 COBOL programs, caught a money-moving security hole and ran COBOL and Java side by side to show the same output. They also showed a 500K-line Java 8 to 17 upgrade.

$17/moDaysAdvanced

Claude Code Claude Opus 5.5

Dev & opsX · @razeden0

Port a C server to Rust with one prompt and a test loop

Claude Code's creator handed Sonnet 5.5 a whole C server and the tests, then let it loop: do the job, run the tests, fix, run again. The same port with the top model took 12 hours and about twice the cost.

$17/mo1 dayAdvanced

Claude Code Claude Sonnet 5.5 Rust

Vibe coding & appsX · @rauchg

Port an Electron app to Rust and Swift with coding agents

Vercel's CEO ported his Mini web browser from Electron and Bun to Rust and Swift, built with Opus 5.5 and Sol 6. It bundles up-to-date Chromium through the cef crate and embeds an agent that talks to his local CLI over ACP and controls the browser through an MCP server.

$4 in / $20 out per 1M tokensWeeksAdvanced

Claude Opus 5.5Sol 6Rust

Dev & opsHacker News · jawiggins

Have agents port a large library to Rust

Had coding agents build Xmloxide, a Rust replacement for libxml2.

$17/moweeksAdvanced

Claude Code Rust

Common questions

How do you port code to another language with AI?: Give a coding agent such as Claude Code or Codex the whole job plus a test suite that defines correct behavior, then let it loop: port, run the tests, fix, run again. The examples below include a C server moved to Rust in 9.5 hours, 700K lines of COBOL migrated with outputs compared side by side in Java, a backend moved from .NET to Hono in 36 days and 24 files converted to TypeScript for $0.71 by a swarm of small agents. Write or capture tests before you start, port in small units, and run the old and new versions on the same inputs before you switch over.
Which AI tools do people use to port code to another language?: Across the 9 sourced use cases in this guide, the most used tools are Claude Code, OpenAI Codex, Rust, Claude Opus 5.5, Claude Sonnet 5.5.
How much does it cost to get started?: 1 of the 9 use cases can start on a free plan. The most common paid starting price is $17/mo (7 use cases). Prices come from each tool's official pricing page.
How long does setup take?: 1 of the 9 use cases lists a setup time of an hour or less. Each card shows the setup time the builder reported.
Are these real examples?: Yes. Every use case links to its public source (an X post, a Hacker News thread or a GitHub repo) with the author and date, so you can check it yourself.

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