Given all the recent press about bun rewriting 500k lines of zig into rust at a cost of $165K tokens of Fable in an 11 day sprint, would be super interested to hear about your experience and approach.
We did the same thing. It took me a few iterations to get the library right, but overall I used approx 10 billion tokens here across a codex and Claude max plan
The first iteration was a rewrite using codex /goal but it ended up producing junk
The second iteration was fable controlling gpt-5.5 agents to write the code with really strong acceptance tests. This pushed the library in the right direction and is basically what you see here today
Given all the recent press about bun rewriting 500k lines of zig into rust at a cost of $165K tokens of Fable in an 11 day sprint, would be super interested to hear about your experience and approach.
We did the same thing. It took me a few iterations to get the library right, but overall I used approx 10 billion tokens here across a codex and Claude max plan
The first iteration was a rewrite using codex /goal but it ended up producing junk
The second iteration was fable controlling gpt-5.5 agents to write the code with really strong acceptance tests. This pushed the library in the right direction and is basically what you see here today
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