docs(question-types): document interaction contract

.agents/learnings/promoted/2026-09-05-question-type-contract-drift.md

@@ -0,0 +1,40 @@
+---
+id: 2026-09-05-question-type-contract-drift
+date: 2026-09-05
+status: promoted
+scope: question interaction contract documentation
+evidence: npm run lint:harness and npm run learn:check
+destination: docs/question-types.md, scripts/lint-harness.mjs, AGENTS.md, and .codex/skills/question-pack/SKILL.md
+review_after: 2026-12-05
+---
+
+## Symptom
+
+Maintained documentation did not identify the implemented question interaction
+types, their response payloads, or their matching semantics. The only detailed
+reference was a historical implementation plan, so content and product work
+could not rely on maintained documentation.
+
+## Reproduction
+
+Compare `QuestionType` in `packages/shared/src/types/index.ts` and the question
+renderer and answer matching code with `docs/index.md`, `docs/schema.md`, and
+`docs/question-selection.md`.
+
+## Cause
+
+The interaction contract was added to code without a maintained documentation
+owner or a verification check linking the document to the canonical union.
+
+## Remediation
+
+Create `docs/question-types.md` as the maintained interaction contract. Require
+agents and the question-pack workflow to update it with type or semantic
+changes. Add a harness invariant that compares its type marker to the shared
+`QuestionType` union.
+
+## Evidence
+
+`npm run lint:harness` reads the shared union and the documentation marker and
+fails when their ordered type lists differ. `npm run learn:check` validates this
+promoted learning record and its destination metadata.

.codex/skills/question-pack/SKILL.md

@@ -7,6 +7,11 @@ description: Create or review Sauci question-pack content and its local migratio
 
 Inspect existing packs before generating to avoid duplication.
 
+Before creating or editing content that uses a question interaction type, read
+`docs/question-types.md`. If the type, response payload, configuration, or
+matching semantics change, update that maintained contract and run
+`npm run lint:harness` in the same task.
+
 - Write proposals, not interview questions; use gender-neutral “your partner”.
 - Avoid time-bound words such as tonight, now, or today.
 - Symmetric activities have no partner text.

AGENTS.md

@@ -87,6 +87,9 @@ environment limitation; do not call it a passing product check.
 ## Documentation discipline
 
 Update the maintained doc when a contract, command, port, or invariant changes.
+When question interaction types, response payloads, configuration, or match
+semantics change, update `docs/question-types.md` in the same change and run
+`npm run lint:harness` to prove its type list matches the shared contract.
 Plans and historical notes are evidence, not current architecture. A repeated
 lesson becomes permanent only after it is reproduced and promoted into a doc,
 skill, fixture, or executable check.

docs/index.md

@@ -20,6 +20,7 @@ historical notes. Agents should load only the section relevant to their task.
 - [Couple pairing](couple-pairing.md)
 - [Couple streaks](couple-streaks.md)
 - [Question selection](question-selection.md)
+- [Question interaction types](question-types.md)
 - [Match notifications](match-notifications.md)
 - [Subscriptions](subscription-system.md)
 - [Redemption codes](product/redemption.md)

docs/question-types.md

@@ -0,0 +1,45 @@
+# Question interaction types
+
+This is the maintained contract for the question interactions delivered through
+the daily question flow. It is separate from the [couples quiz](quiz.md) and
+[dares loop](dares-loop.md), which have their own content and completion
+models.
+
+<!-- question-types: swipe,text_answer,audio,photo,who_likely -->
+
+## Supported types
+
+| Type | User interaction | `response_data` and `config` | Match semantics |
+| --- | --- | --- | --- |
+| `swipe` | Choose yes or no, or skip. | No `response_data`; `config` is unused. | A no creates no match. The API also retains `maybe` matching for stored or replayed answers, producing `yes_maybe` or `maybe_maybe`; the current mobile card does not offer maybe. |
+| `text_answer` | Write an answer and send it, decline with no, or skip. | `response_data`: `{ type: 'text_answer', text }`; `config` is unused. | Both partners must answer without a no. The match type is `both_answered`, with both payloads in `response_summary`. |
+| `audio` | Record and send an audio answer, or skip. | `response_data`: `{ type: 'audio', media_path, duration_seconds }`; optional `config.max_duration_seconds` limits recording and defaults to 60 seconds in the admin UI. | Both partners must answer without a no. The match type is `both_answered`, with both payloads in `response_summary`. |
+| `photo` | Take or select and send a photo answer, or skip. | `response_data`: `{ type: 'photo', media_path }`; `config` is unused. | Both partners must answer without a no. The match type is `both_answered`, with both payloads in `response_summary`. |
+| `who_likely` | Choose which partner is more likely. The current mobile flow submits this as yes. | `response_data`: `{ type: 'who_likely', chosen_user_id }`; `config` is unused. | Once both partners respond, the match type is `both_answered`; the stored answer value does not gate that type's match calculation. Both choices are in `response_summary`. |
+
+## Persistence and implementation ownership
+
+`questions.question_type` defaults to `swipe`; the database check constraint and
+the canonical shared `QuestionType` union must contain the same values.
+`questions.config` is JSON configuration for a type. `responses.response_data`
+stores an individual non-swipe payload. `matches.response_summary` is a JSON
+object keyed by responder user ID and is populated for `both_answered` matches.
+
+The canonical list is `QuestionType` in
+[`packages/shared/src/types/index.ts`](../packages/shared/src/types/index.ts).
+The database constraint is in
+[`apps/api/drizzle/0003_answers_matches.sql`](../apps/api/drizzle/0003_answers_matches.sql).
+Match calculation is in
+[`apps/api/src/domains/answers/types.ts`](../apps/api/src/domains/answers/types.ts),
+the mobile renderer is
+[`apps/mobile/src/features/swipe/components/SwipeQuestionCard.tsx`](../apps/mobile/src/features/swipe/components/SwipeQuestionCard.tsx),
+and admin authoring options are in
+[`apps/admin/src/pages/content/QuestionsPage.tsx`](../apps/admin/src/pages/content/QuestionsPage.tsx).
+
+## Change rule
+
+When adding, removing, or changing a question type, its payload, configuration,
+or matching semantics, update this document in the same change. Update the
+shared type, database constraint, API, mobile, and admin consumers as required.
+`npm run lint:harness` checks the documented type list against the canonical
+shared union so an unreviewed list change fails routine verification.

docs/schema.md

@@ -47,6 +47,8 @@ erDiagram
         uuid pack_id FK
         text text
         text partner_text "for two-part questions"
+        text question_type "swipe/text_answer/audio/photo/who_likely"
+        jsonb config "type-specific configuration"
         int intensity "1-5"
         text[] allowed_couple_genders "couple composition filter"
         text[] target_user_genders "individual user filter"
@@ -70,6 +72,7 @@ erDiagram
         uuid question_id FK
         uuid couple_id FK "nullable: null is a sealed solo answer, claimed at pairing"
         answer_type answer "yes/no/maybe"
+        jsonb response_data "non-swipe answer payload"
         timestamptz created_at
     }
 
@@ -77,7 +80,8 @@ erDiagram
         uuid id PK
         uuid couple_id FK
         uuid question_id FK
-        match_type match_type "yes_yes/yes_maybe/maybe_maybe"
+        match_type match_type "yes_yes/yes_maybe/maybe_maybe/both_answered"
+        jsonb response_summary "both non-swipe payloads by user"
         boolean is_new
         timestamptz created_at
     }
@@ -161,7 +165,8 @@ erDiagram
 | Enum | Values |
 |------|--------|
 | `answer_type` | `yes`, `no`, `maybe` |
-| `match_type` | `yes_yes`, `yes_maybe`, `maybe_maybe` |
+| `question_type` | `swipe`, `text_answer`, `audio`, `photo`, `who_likely` |
+| `match_type` | `yes_yes`, `yes_maybe`, `maybe_maybe`, `both_answered` |
 | `feedback_type` | `bug`, `feature_request`, `general` |
 | `feedback_status` | `new`, `reviewed`, `in_progress`, `resolved`, `closed` |
 | `subscription_status` | `active`, `cancelled`, `expired`, `billing_issue`, `paused` |
@@ -188,11 +193,21 @@ allowed.
 
 ## Key Flows
 
+### Question interactions
+
+`questions.question_type` defaults to `swipe`; `questions.config` holds
+type-specific settings. A non-swipe response keeps its payload in
+`responses.response_data`. When a non-swipe interaction resolves as
+`both_answered`, `matches.response_summary` holds both payloads keyed by user
+ID. The complete interaction and match contract is maintained in
+[Question interaction types](question-types.md).
+
 ### Response & Match Flow
-1. User submits response via `submit-response` edge function
+1. User submits a response to the standalone API at `POST /v1/responses`
 2. Response saved to `responses` table (UPSERT on `user_id, question_id`)
-3. Function checks for partner's response on same question
+3. API checks for the partner's response on the same question
-4. If both answered positively (not "no"), a `match` is created
+4. API applies the [question interaction contract](question-types.md) to create,
+   update, or remove a `match`
 5. Match triggers push notification to both partners
 6. Match unlocks chat thread in `messages` table
 

scripts/lint-harness.mjs

@@ -1,7 +1,8 @@
 import { access, readFile, readdir } from 'node:fs/promises';
 import path from 'node:path';
+import { fileURLToPath } from 'node:url';
 
-const root = path.resolve(new URL('..', import.meta.url).pathname);
+const root = path.resolve(fileURLToPath(new URL('..', import.meta.url)));
 const errors = [];
 const scoped = process.argv.includes('--scope');
 
@@ -156,6 +157,22 @@ if (!scoped) {
     if (!(await exists(target))) fail(path.join(root, 'docs', 'index.md'), `broken documentation link ${match[1]}`, 'correct the link or restore the maintained document');
   }
 
+  const sharedTypesFile = path.join(root, 'packages', 'shared', 'src', 'types', 'index.ts');
+  const sharedTypes = await readFile(sharedTypesFile, 'utf8');
+  const union = sharedTypes.match(/export type QuestionType\s*=\s*([^;]+);/);
+  const canonicalQuestionTypes = union?.[1].match(/'([^']+)'/g)?.map((value) => value.slice(1, -1));
+  const questionTypesDoc = path.join(root, 'docs', 'question-types.md');
+  const questionTypesSource = await readFile(questionTypesDoc, 'utf8');
+  const documentedQuestionTypes = questionTypesSource.match(/<!-- question-types:\s*([^>]+)\s*-->/)?.[1]
+    .split(',').map((value) => value.trim()).filter(Boolean);
+  if (!canonicalQuestionTypes?.length) {
+    fail(sharedTypesFile, 'QuestionType union could not be read', 'keep QuestionType as a quoted string union');
+  } else if (!documentedQuestionTypes?.length) {
+    fail(questionTypesDoc, 'question type contract marker is missing', 'add <!-- question-types: type-a,type-b --> with every supported type');
+  } else if (canonicalQuestionTypes.join(',') !== documentedQuestionTypes.join(',')) {
+    fail(questionTypesDoc, 'documented question types differ from the shared QuestionType union', `set the contract marker to ${canonicalQuestionTypes.join(',')}`);
+  }
+
   const mcpAuth = await readFile(path.join(root, 'apps', 'mcp', 'src', 'lib', 'auth.ts'), 'utf8');
   if (/allowing all requests|query\(['"]apiKey/i.test(mcpAuth)) {
     fail(path.join(root, 'apps', 'mcp', 'src', 'lib', 'auth.ts'), 'MCP authentication can leak or fail open', 'require a configured Bearer token and fail closed');

scripts/validate-learnings.mjs

@@ -1,7 +1,8 @@
 import { readFile, readdir } from 'node:fs/promises';
 import path from 'node:path';
+import { fileURLToPath } from 'node:url';
 
-const root = path.resolve(new URL('..', import.meta.url).pathname);
+const root = path.resolve(fileURLToPath(new URL('..', import.meta.url)));
 const base = path.join(root, '.agents', 'learnings');
 const requiredSections = ['## Symptom', '## Reproduction', '## Cause', '## Remediation', '## Evidence'];
 const failures = [];
@@ -11,7 +12,7 @@ for (const state of ['inbox', 'promoted']) {
   for (const name of await readdir(directory)) {
     if (!name.endsWith('.md')) continue;
     const file = path.join(directory, name);
-    const source = await readFile(file, 'utf8');
+    const source = (await readFile(file, 'utf8')).replace(/\r\n/g, '\n');
     const frontmatter = source.match(/^---\n([\s\S]*?)\n---/);
     if (!frontmatter) { failures.push(`${file}: missing YAML frontmatter`); continue; }
     const fields = Object.fromEntries(frontmatter[1].split('\n').map((line) => {