I build inspectable developer tools and contribute fixes upstream. My current projects help make subtle regressions visible: duplicate test identities, lost approval state, and calls that do not overlap as intended.

Explore the tools · See merged contributions · Report a reproducible problem

junit-collision-check — Find duplicate JUnit test identities across shards and retries, including conflicting outcomes a report consumer could hide.

For teams combining XML reports in CI. Python 3.12+ with Expat 2.6.0+.

Listed in awesome-testing under Test Report Diagnostics.

Broken/control demo · pytest CI integration · Input/output contract

A collision-free result is not a passing test run. Keep the test runner's failure gate.

approval-history-kit — Check saved AI SDK approval histories and compare approval metadata before and after a declared lossless save/reload.

For application developers testing persistence. TypeScript library and CLI; Node.js 22/24; adapter pinned to ai@7.0.127 JSON ModelMessage.

Save/reload regression demo · Choose a checkpoint · Release archive

History integrity is not authorization, provider acceptance, or validation of arbitrary conversation formats.

fanout-check — Check whether explicitly grouped tool or subagent calls overlap, using same-clock recorded intervals and a timing contract.

For developers adding regression checks to async workflows. Python 3.10+.

Blocking/cooperative demo · Agents SDK component example · Trace format

Overlap does not establish correct outputs, safe independence, or end-to-end speedup.

All three are early-stage, MIT-licensed tools with runnable synthetic examples. They run locally without API keys or a hosted service. Start from each repository's source or GitHub release instructions; no npm/PyPI publication is assumed.

DSH A2UI · Development preview 0.1.0-alpha.13. An independent DeepSeek Harness plugin that renders A2UI forms and sends their actions into the next conversation turn.

For developers exploring conversational interfaces. The published plugin targets a bounded A2UI v0.9/v0.9.1 path; full protocol coverage and live-model workflows are not certified.

No-key agent-loop walkthrough · Native Web-host evidence and screenshots

The walkthrough uses a scripted model and jsdom. Separately, native-host run 40092097281 passed on October 24, 2026 at source a8bb06d8 (alpha.8): two isolated sessions, action retry, cancellation and graceful restart without replaying historical actions. That result covers the exact synthetic scenario, not every later version or a live model.

Merged work in projects maintained by others. These links show the actual changes and review history, not ownership of the upstream projects.

• Vercel AI SDK · Contributed the original fix for duplicate local tool execution from identical approval replays in #23525. Maintainer gr2m extended it and merged #23791 with co-author credit on October 21, 2026. Released in ai@7.0.149 on October 22.
• DSH GenUI, October 23, 2026 · Merged contributions for slider display/submission precision, safe table source links, native galleries, and explicit sidechat surfaces. Native Desktop link navigation remains unverified; sidechat delivery still depends on Better Sidebar #1033. These merges do not establish a release or user adoption.
• DSH GenUI · Preserve table row details/state after filtering, scale plot dragging to rendered width, scope DOM-fence observer maintenance, and opt-in plain-text copy preview. Merged October 21, 2026.
• SQLFluff · Prevent trailing line comments from swallowing the next statement when CV06 moves semicolons to their own line. Merged October 24, 2026.
• SQLFluff · Parse Snowflake date parts by function argument position. Merged October 20, 2026.

Start with the broken example and its valid control, then check the documented input contract and limits before integrating. Each repository includes development and contribution instructions.

For a bug report, open an issue in the relevant repository with the version, expected result, and a minimal synthetic or sanitized example. Review logs and report output for private data before sharing. Please do not post credentials or customer data.

_{The header is an original illustration. Project diagrams explain workflows; they are not screenshots or benchmark results.}