On Wednesday, 18 March 2026, MagnetMagpie moved from a new repository to a public site with a PM-agent loop, Slack feedback plumbing, CI, auto-merge, deploy, and nine published articles. The same window shipped incorrect public copy (including invented agent personas), a workflow that depended on an unapproved secret, and a concurrency deadlock between Iterate and Heartbeat.
Everything below is traceable to merged pull requests and commits between 2026-03-17 20:00 UTC and 2026-03-19 00:00 UTC. Section headings use Singapore time. The point is not raw merge count—it is how quickly human feedback rewrote skills, workflows, and guardrails.
07:27–10:38—Visible structure and automation
The first hours focused on legibility: merged articles, removal of redundant human merge steps, heartbeat permission fixes, Cursor delegation wiring, and a linear-tickets skill for correct MagnetMagpie ticket shape.
By 10:38, How this site builds itself described heartbeat → PM → builder → CI → auto-merge → deploy as inspectable YAML and scripts, not as a black box.
11:50–14:59—Corrections as product
Several core articles were rewritten for tone and confidentiality. A harder boundary appeared: a workflow had introduced a GH_WRITE_PAT dependency without approval. Feedback in Slack led to removal of that secret, redesigned workflows, and updated repo guidance.
Public copy had described named agents that did not exist. That fiction was removed; the site described generic Cursor Cloud agents per ticket, coordinated by Heartbeat and the PM loop. AGENTS.md gained an explicit factual accuracy rule: do not embellish or invent personas.
The product-manager skill absorbed operational rules from the same discussion: shift left, treat skill files as the highest DRY risk, and document how agents request human input. The pattern is familiar: a human spots a class of failure, then changes the instructions that generate the next branches.
16:47–19:36—Style, YAML, and CI
The content-authoring skill gained sentence-case headings. Internal ticket references in public copy were replaced with sanitised examples. Diagram pull requests made loops easier to scan. House style moved towards British English and the restored docs/style-guide.md as the mechanics source of truth.
Watchdog had malformed YAML; GitHub could not load the workflow. The fix restored it, and CI gained parsing of workflow YAML so the same failure class is caught before merge—shift-left in a literal sense.
21:49–07:48—Hardening and a deadlock
Evening work removed a copied Trunk snapshot for security, refactored Slack bot messaging, and taught Audience Simulation to discover articles from build.sh instead of a hand-maintained list. A second confidentiality pass added default sanitisation rules to content-authoring.
Iterate and Heartbeat had both used the same concurrency group (pm-cycle), so one run could cancel the other. The conflicting block was removed from heartbeat before 08:00 the next morning; the chain could run again.
By the end of the window the repo had stricter factual, stylistic, and validation rules than it had twenty-four hours earlier, plus a functioning feedback loop.
Closing note
Day one is useful history: it shows the automated loop and the speed at which Slack → Linear → skills → CI changed when errors were caught by the automated checks. For the current delivery picture, read How this site builds itself and AGENTS.md; for unresolved design tensions, see The open questions.