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Coding Agents Alpha Tracker
Long unattended agent runs: Willison's overnight Ultracode rebalance and Steinberger's 600-PR migration with a planner, a coder and a challenger
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Two practitioners show multi-day, mostly autonomous agent work and how they set it up. Also: verification paths for agents, AGENTS.md as a scheduler for follow-up work, OpenAI's longer cache retention, and a large T3 Code Stable release.

Long runs: give a blunt goal, then a structured brief

Simon Willison built Battle Drones, a browser RTS, mostly with Claude Code. Two of his prompts are worth reusing.

  • A vague goal plus orchestration. He sent Opus 5.5 the prompt "This game isn't fun enough yet. Make it a LOT more fun." in Ultracode mode, where Claude Code runs "dynamic workflows": JavaScript scripts that orchestrate many subagents at once . The run took from evening until late the next morning . Claude ran more than a thousand simulated playtests and used the results to rebalance units and add features. In 1,200 AI-vs-AI matches, games still undecided after 25 minutes fell from 14% to 0.9% .
  • Research and critique before building. When the game's AI ignored infantry and troop carriers, he wrote a detailed design brief: the incentives, the map constraints and the win condition. It ended with "First research and then critique this design. Only build after we have agreed on any modifications" . The result was the Archipelago map, which he calls the most fun map in the game .

Other lessons from the project:

  • Static HTML/JS with Three.js is a strong medium for agent-built games because the models know those platforms well .
  • Giving Claude an OpenAI API key lets it generate images, look at them and refine its prompts .
  • Replays and multiplayer need a deterministic simulation. Claude had to replace Math.sin()/Math.cos() with custom versions because Chrome and Safari returned slightly different numbers .

Peter Steinberger started a loop to move OpenClaw's Lit frontend to Solid 2.0. Removing Lit took about 6 days, and making the code idiomatic Solid took another week. He checked in every other day, and the work took about 600 PRs . The agent missed a few small regressions, mostly button shapes and minor UX details . His setup:

  • Astra plans and Sol 6.1 codes. Prompting Astra to run Codex CLI in worktrees worked "FAR better than relying on subagents" .
  • A second agent challenges the first. Instead of one agent checking its own progress against a text file, as with /goal, a separate agent pushes back on Astra. He built this as an OpenClaw plugin he calls "smart goal" .

He also moved OpenClaw to tsrs (npx tsrs). Its announcement describes a Rust port of the TypeScript compiler, built in collaboration with the TypeScript team. It claims up to 8x the speed of TS 7.0 and about 70% less memory, runs in WASM, and is due to join Oxc . Steinberger calls it a drop-in replacement and saw about a 5x speedup , or 9x against stable releases, since they were already on 7.1-dev .

Give agents a paved path to verification

Kent C. Dodds says the fix for low confidence in legacy codebases is verification. Agents should do what humans did: run with mock data, use the UI, seed varied database data and deploy to a production-like environment. They will do this reliably if you give them a paved path . His agents maintain a control-kody CLI for exactly this (SKILL.md) . Separately, a team that was "all in" on agents turned out not to be running tests in CI. Dodds calls that a prompting problem: an agent asked to audit the codebase for obvious problems would have caught it .

Theo reported something similar after a rough night. Most breakages came from legacy vendors, GitHub Actions and flaky Chromium-driver tests. The "slop" parts, such as ts-rust, were stable . In a new video, he describes building his machine images for the agents rather than for himself. The image is a customized, headless Ubuntu with Bash instead of Zsh. His audit found over 30% of Claude's errors came from Zsh's newline handling breaking ripgrep commands, and agents also did worse on Arch and CachyOS dev boxes .

AGENTS.md as a scheduler for follow-up work

After the eMudhra CA key leak, Geoffrey Huntley asked an agent whether his NixOS fleet was affected. Because Nix has a single source of truth, one patch covers transitive dependencies: patch, commit, autodeploy . His new trick is to have the agent write a dated reminder into AGENTS.md so the temporary workaround gets backed out later . The reminder names the nixpkgs commit to check for, the command to run, a recheck every two days, which files to delete, and which unrelated changes to keep .

Overalls also got "hive mode." Agents in the same profile zone (oss, standard or customer) share a message board for coordinating work. The customer zone has no outbound connectivity, and a machine's entries are wiped when it suspends . Huntley points to Claude Code's crossSessionInbound=accept setting as the apparent primitive behind hive swarms , and says it has him "back to loving claude" . He is moving 95% of his usage to Anthropic because OpenAI "falls over" after every usage reset .

OpenAI: longer cache retention and a usage-limit fix

The API now offers 12-hour prompt caching, so persistent agents pay the cached-input rate even when requests are hours apart . Tibo says logged-in Codex and Work users get cache kept "forever," with guaranteed hits when they resume old conversations . OpenAI also says about 40,000 accounts had usage limits that didn't match their plan. It has corrected the issue and will add credits for affected users .

T3 Code Stable

The new T3 Code Stable release has more than 1,400 changes . Highlights:

  • Add a project to another machine from the "Run on" menu.
  • PR diffs that separate code, tests and docs.
  • Idle Claude threads compact early so the cache stays warm (beta).
  • t3 connect reachability checks.
  • Webhook-task filters and dedupe.
  • More reliable skill discovery .

Theo suggests moving back to Stable because Nightly is getting more experimental .

Other notes

  • Tenex's "meta harness" is structured repo docs plus a CLI that agents use to drive plans and readouts. Agents log their decisions, and everything is checked into Git, so the reasons behind changes live in the repo . Tenex has loosened the plan template as models improved . Its engineers mostly drive with Opus 5.5 and use Codex to review, which they say gives the best results . They report output roughly doubled this year .
  • Claude Code Projects tip: tell the coordinator to save a project-memory rule to post a one-line update linking the thread whenever a thread is blocked or finishes a milestone. Before this, it wouldn't even report blocked threads .
  • Kody lets agents file feedback about their experience, which often becomes a fix within an hour or two .

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