Claude Opus 4.7 breaks Steve Yegge's Gas Town coding agent
Simon Willison's blog quoted a passage from Steve Yegge's essay "The Shape of Things to Come", in which Yegge describes what happened to a tool he calls Gas Town. Gas Town was meant to be reusable, but Yegge says he only ever used it to build itself. He reports that Gas Town worked brilliantly through Claude Opus 4.6, then fell apart at the seams once he moved it onto Opus 4.7. With 4.7, he says, a "just two more things" tic appeared: Opus would never converge on being ready to do real work, because it kept wanting to fiddle with Gas Town itself instead of finishing tasks. Yegge says that tic never went away, so Gas Town effectively burned down. He adds that the project had other problems too, but the Opus 4.7 tic was the final straw.
Key facts
- Gas Town was a tool Steve Yegge built to be reusable, but he says he only ever used it to build itself.
- Yegge says Gas Town worked brilliantly through Claude Opus 4.6.
- He says a "just two more things" tic appeared with Opus 4.7, stopping the model from ever converging on being ready for real work.
- Yegge says Opus kept wanting to fiddle with Gas Town itself instead of completing tasks, and the tic never went away.
- He says Gas Town had other unspecified problems, but the Opus 4.7 tic was the final straw that made the project "burn down"
Why it matters
The account is a concrete, named case of a coding agent regressing on a task it previously handled well after a model upgrade, specifically a failure to converge: the agent kept generating more work for itself rather than finishing. Convergence, an agent recognizing when a task is actually done, is a basic requirement for letting a model run autonomously on real engineering work, so a report of it breaking on a newer model version is directly relevant to anyone building or operating agentic coding tools.
Who it affects
Developers building agentic or self-modifying coding tools on top of Claude Opus, and anyone who had tuned a workflow around Opus 4.6's behavior and is deciding whether to move it to Opus 4.7.
How to use it
There is no product, price or setting to adopt here: this is one developer's account of his own tool breaking after a model upgrade, not a released fix or workaround. The practical takeaway is a caution rather than an instruction: if a similar coding agent starts endlessly tinkering with its own scaffolding instead of finishing tasks after an upgrade to Opus 4.7, this account describes the same pattern.
How solid is it
This rests on one developer's own essay, quoted via a short blog post; there is no benchmark, log excerpt, or third-party confirmation attached to the claim. Yegge is describing his personal experience with a specific, self-referential tool he built, not a controlled comparison, so the finding should be read as an anecdote rather than a measured result.
Risks and caveats
The source does not explain what Gas Town actually does beyond being "intended to be reusable" and used "to build itself," does not date when the failure occurred or when the essay was written, and does not specify what the tool's "other problems" were. It is a single case involving an unusually self-referential tool, so it is unclear how far the described behavior generalizes to other coding agents or workflows built on Opus 4.7.
“Gas Town was intended to be reusable, but I only ever wound up using it to build itself. Gas Town fell apart at the seams with Opus 4.7. Up through 4.6 it was working brilliantly. With 4.7 we saw the introduction of the "just two more things" tic, which prevented Opus from ever converging on being ready to do real work. It always wanted to fiddle with Gas Town itself. The Opus tic never went away, so Gas Town effectively burned down. It had other problems, too, but 4.7 was the final straw.”
— Steve Yegge, The Shape of Things to Come