Direct Messaging Backend — Conversations, Cursor Messages, Read State (Hard)

[aji70]

Task: Direct Messaging Backend — Conversations, Cursor Messages, Read State (Hard)

Overview

No messaging layer exists. Deliver a production-shaped DM stub API: unique conversations, participant authz, cursor pagination, read receipts, rate limits, and abuse guards — enough for the hardened frontend messages UI.

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Scope (must all ship)

Entities

• Conversation: fanId, creatorId, unique pair, lastMessageAt, optional lastMessagePreview
• Message: conversationId, senderId, body, createdAt, readAt, optional clientId for idempotent send

Endpoints

• POST /api/v1/conversations — fan starts (or get-or-create) with creator
• GET /api/v1/conversations/me?cursor&limit — inbox ordered by lastMessageAt
• GET /api/v1/conversations/:id/messages?cursor&limit
• POST /api/v1/conversations/:id/messages — participant; supports Idempotency-Key/clientId
• POST /api/v1/conversations/:id/read — mark messages read up to timestamp/id

Rules

• Non-participant → 403
• Duplicate pair reuses conversation
• Body 1..2000 chars; strip/reject empty
• Optional: only fans may initiate; creators reply (document)
• Rate limit sends per user (in-memory/token bucket stub OK)

Pagination

• Messages oldest→newest within page; cursor stable
• Inbox pagination

Safety

• Block soft-deleted users from new messages
• Do not leak other conversations via sequential ids (404 vs 403 policy documented)

Testing (≥14)

• Get-or-create uniqueness
• Two-way exchange
• Non-participant forbidden
• Validation errors
• Cursor pages
• Read receipt updates
• Idempotent send
• Rate limit trip (unit)
• Unauth 401

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Deliverables

• MessagingModule, migrations, Swagger, docs/messaging.md, ≥14 tests

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Acceptance Criteria

• Full inbox/thread/read/idempotent send contract
• Authz airtight
• CI green

Out of scope

• WebSockets/SSE push (polling contract only)
• Group chats / attachments (stub flag OK)

[martinzhames]

hi maintainer am a full-stack dev can i please jump on this issue

[grantfox-oss]

🦊 GrantFox — @martinzhames has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #50)
2. Your PR will be reviewed by the MyFanss maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign | FWC26 campaign!

@martinzhames's PR #72 was approved and merged by @aji70.

🏆 @martinzhames: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (188 total points). Track your full progress on GrantFox.

👏 Great work, @martinzhames! Keep contributing to MyFanss.