ADR 0006 — Exclusive write paths for parallel agents

Status: accepted
Date: 2026-09-19

Context

ADRs 0001 through 0005 cut the product. Later agents will implement features in parallel. Shared files (EndpointUri, Account, Appointment) will collide if each agent owns a whole Stitch module.

Stitch screens were still unread in this session. The pack must stay at capability level.

Decision

The unit of later implementation is a work package in ai-agent/tasks/, indexed by docs/work-packages.md and manifest/work-packages.tsv.

Rules:

• One agent writes one package's paths. Paths live in manifest/owned-paths.tsv.
• WP-00 lands reserved HTTP constants and persistence rules before G1.
• G1 packages (identity, two profiles, admin) may run in parallel after WP-00.
• Appointment has one table. WP-05 owns both the patient booking HTTP and the clinician agenda HTTP.
• Imaging and lab stay in diagnostics with kind. WP-07 owns that package. WP-08 only projects reads to the patient.
• Admin does not create a second user table.
• Screen names wait for WP-10 after an in-repo Stitch export.

python3 ai-agent/scripts/check-agent-pack.py is the gate. A pack edit that fails the script does not land.

Consequences

• Parallel work is possible on G1 and on G2 booking-versus-diagnostics.
• Encounter and patient results stay sequential.
• A missing HTTP path is a WP-00 change, not a feature-package invention.
• Consult (F-01) stays blocked until WP-10.