---
phase: 14-multi-signer-schema
plan: "01"
subsystem: database-schema
tags: [schema, drizzle, multi-signer, migration]
dependency_graph:
  requires: []
  provides: [multi-signer-schema-columns, DocumentSigner-interface, getSignerEmail-helper]
  affects: [phase-15-backend, phase-16-ui]
tech_stack:
  added: []
  patterns: [additive-nullable-columns, jsonb-typed-columns, safe-reader-helper]
key_files:
  created:
    - teressa-copeland-homes/drizzle/0010_sharp_archangel.sql
    - teressa-copeland-homes/drizzle/meta/0010_snapshot.json
  modified:
    - teressa-copeland-homes/src/lib/db/schema.ts
decisions:
  - "documents.signers JSONB shape is { email, color }[] — not string[] — so Phase 16 can retrieve consistent per-signer colors from DB without recalculating"
  - "signingTokens.signerEmail is nullable TEXT — NULL = legacy single-signer token, no existing token creation code requires changes"
  - "documents.completionTriggeredAt is nullable TIMESTAMP used as atomic completion guard in Phase 15 UPDATE...WHERE completionTriggeredAt IS NULL"
  - "SignatureFieldData.signerEmail? follows exact same additive-nullable pattern as type? — zero breakage to existing JSONB field rows"
  - "No Partially Signed status added to documentStatusEnum — partial state computed dynamically in Phase 16 by counting used tokens"
metrics:
  duration: "5 min"
  completed_date: "2026-04-03"
  tasks_completed: 2
  files_modified: 3
---

# Phase 14 Plan 01: Multi-Signer Schema Summary

Additive Drizzle migration 0010 adding signerEmail to SignatureFieldData and signingTokens, plus signers JSONB and completionTriggeredAt to documents — all nullable, zero backfills, TypeScript compiles cleanly.

## What Was Built

Three new nullable database columns and one TypeScript interface extension, establishing the data foundation for Phases 15 (sign handler rewrite) and 16 (multi-signer UI):

1. `SignatureFieldData.signerEmail?: string` — optional field ownership routing (absent = legacy single-signer)
2. `getSignerEmail(field, fallbackEmail)` helper — safe reader following the same pattern as `getFieldType()`
3. `DocumentSigner` interface — `{ email: string; color: string }[]` shape for the signers JSONB array
4. `documents.signers JSONB` — per-signer list with assigned colors; NULL = legacy single-signer document
5. `documents.completionTriggeredAt TIMESTAMP` — atomic completion guard for Phase 15's race-safe handler
6. `signingTokens.signerEmail TEXT` — per-token signer identity; NULL = legacy single-signer token

Migration `0010_sharp_archangel.sql` contains exactly 3 `ALTER TABLE...ADD COLUMN` statements — no DROPs, no ALTER TYPEs, no backfills.

## Tasks

| Task | Name | Commit | Files |
|------|------|--------|-------|
| 1 | Add multi-signer types and columns to schema.ts | c658f13 | src/lib/db/schema.ts |
| 2 | Generate Drizzle migration and apply it | 3639491 | drizzle/0010_sharp_archangel.sql, drizzle/meta/_journal.json, drizzle/meta/0010_snapshot.json |

## Decisions Made

- `documents.signers` uses `{ email, color }[]` JSONB shape so Phase 16 PreparePanel can render consistent signer-assigned colors without recalculating by index position
- `signerEmail` on `SignatureFieldData` is optional (not required) so every existing JSONB field row stored in the DB remains valid with no migration needed
- `completionTriggeredAt` is Phase 14 schema-only; write logic (UPDATE...WHERE...IS NULL RETURNING) is Phase 15 scope
- No `Partially Signed` enum value added — computed dynamically by counting `usedAt IS NOT NULL` tokens in Phase 16

## Verification Results

- `npx tsc --noEmit` exits 0 — no TypeScript errors
- `grep -c signerEmail src/lib/db/schema.ts` returns 6 (>= 3 required)
- Migration SQL contains only `ALTER TABLE...ADD COLUMN` — no DROPs
- Migration applied successfully to local Postgres instance
- No files outside schema.ts and drizzle/ were modified

## Deviations from Plan

None — plan executed exactly as written.

## Known Stubs

None — this plan is schema-only with no UI or data-rendering code paths.

## Self-Check: PASSED

- `teressa-copeland-homes/src/lib/db/schema.ts` — FOUND (modified)
- `teressa-copeland-homes/drizzle/0010_sharp_archangel.sql` — FOUND (created)
- `teressa-copeland-homes/drizzle/meta/0010_snapshot.json` — FOUND (created)
- Commit c658f13 — FOUND
- Commit 3639491 — FOUND