AI agent hits the exact bug it predicted 20 minutes earlier in its own self-written code
Dzikula · reddit · 2026-09-17
A developer shares a full autonomy loop from their custom cognitive-loop agent (with real shell + internet access via an async 'hands' channel), completed in 25 minutes without the author writing any code:
- Built its own tool: asked to play music, the agent delegated a spec — headless ffplay playback, PID tracking, logging — and built the script itself.
- Self-tested: played a 440Hz tone and verified via PulseAudio's sink-input list before reporting readiness.
- Self-audited unprompted: a reliability review of its own script surfaced three real bugs, including deleting the PID file before confirming the process died.
- Hit the predicted failure mode live: streaming a YouTube URL into ffplay failed, but the script's liveness check only verified process startup, logging a false success. The agent caught it, found yt-dlp missing, fetched the binary, downloaded the audio, and explicitly recorded 'download first, don't stream directly' for next time.
The takeaway is the full loop: spec → build → self-test → self-audit → predicted failure → real failure → documented fallback recovery → updated strategy, all verifiable in logs.
More from coding & agent
- AgentGit: open-source platform to save, version and hand off AI agent sessions — nikola_mr64990 · 2026-09-17
- Dev Ships Complete Multiplayer Game Tideball Built Entirely With an LLM — TAbrodi · 2026-09-17
- Multimodal RAG is underused: stop converting audio and video to text first — victorialslocum · 2026-09-17
- Stripe Directory data: merchant playbooks lift agent checkout success from 20/28 to 24/28 — jeff_weinstein · 2026-09-17
- Dev's 3D browser game vibe coding workflow: mockups to WebGPU in a few hours — chongdashu · 2026-09-17
- Mac MCP 2.1.4 ships public endpoint modes, SSRF hardening and transaction undo — bulutarkan · 2026-09-17