Origin
FieldLog exists because pesticide application records sit at the seam between routine work and bet-the-farm liability. The contractor in the field knows what was sprayed, where, when, in what conditions, and at what rate. The manager who answers to regulators needs that record to be honest, traceable, and unaltered between the field and the audit. Most record-keeping in this domain happens in spreadsheets, paper logs, or general-purpose mobile apps where the record can be modified after the fact, where weather is reconstructed from memory, where GPS is approximated. The gap between the work and the record is where compliance fails. FieldLog closes that gap by treating the field record as the regulatory record from the moment of submission.
Design
A contractor arrives at a field, opens the PWA on a mobile device, and logs the application. GPS is captured by the browser. Weather is fetched at the moment of submission. The product, rate, target pest, acreage, start time, and completion time are captured at the source. The AI Compliance Brain evaluates the submission against the EPA Rules Engine and returns an aviation‑style verdict: Passed, Manager Review Required, or Blocked. The record is sealed at submission with a sealed log identifier and an immutable hash. The manager opens the Control Tower, sees the attention queue, and verifies — but cannot edit. Verification is append-only. The original record persists exactly as the contractor submitted it.
Structure
Three layers run twelve features. ApplicationLog is the crown jewel. Its canonical fields — product, rate, acreage, GPS, weather snapshot, timestamps, compliance status, AI verdict, sealed log ID, immutable hash — are written once at submission. After submission, a Supabase Row-Level Security policy blocks updates to canonical fields at the database layer; no application code can override this, because the constraint lives below the application code. Manager verification operates on a separate set of append-only fields: status, verifier signature hash, verified-at timestamp, append-only manager notes array. The sealed log ID format — FL-YYYY-MM-DD-{4 hex} — is human-readable, sortable, and the hex is derived from the SHA-256 hash of the canonical payload. The PWA is offline-first; the sync queue carries records to Supabase when connectivity returns.
Defense
The defensibility claim is that the record submitted in the field is the record the regulator sees. There is no reconciliation step between contractor entry and manager record because no reconciliation is permitted by the database. The Row-Level Security policy is the structural guarantee — not a process, not a policy, not a promise, but a constraint enforced beneath the application.
Manager verification is meaningful precisely because it cannot modify the contractor's facts. The AI verdict is produced once at submission and persists as part of the immutable record; it does not drift, it is not regenerated, it is not retroactively softened. When the manager produces an audit export, the record being exported is the record that was created, sealed, and verified — with the full provenance, the weather snapshot at the moment of application, the GPS at the moment of application, the verdict at the moment of application, and the verifier's signed acknowledgment that the record was reviewed.
Status
Active. Three layers, twelve features, built in a 67-hour build window for the Codefi Vibeathon in Cape Girardeau, Missouri. First-place finish. AI Compliance Brain operational with aviation‑style verdicts. Sealed log immutability enforced at the Supabase Row-Level Security layer.
