psf-memo/specs/feature-backlog.md

psf-memo — Prioritized Feature Backlog

Status: DRAFT — research refresh 2026-08-27. Owner: specifier. Last updated: 2026-08-28

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Goal

Make psf-memo feature-equivalent to memo.cash, a Bitcoin Cash (BCH) social network built on OP_RETURN transactions. Every social action is a BCH transaction carrying a Memo protocol payload (0x6d + action byte) that is broadcast from the client to the chain and later indexed by psf-memo-indexer into psf-memo-db.

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Research notes

• Protocol reference: https://memo.sv/protocol (Wayback Machine snapshot 2025-12-15). It lists action bytes, payload shapes, and byte limits. The page is on the BSV fork (memo.sv) but the action codes match the BCH memo.cash implementation.
• memo.cash access: the live site is behind Cloudflare. Direct curl and headless Firefox login attempts from this environment were blocked, so the roadmap is derived from the protocol spec plus an audit of the existing mono-repo code.
• Implementation audit (2026-08-27):
  • Indexer already has handlers for: setName, post, reply, like, setProfile, follow/unfollow, setProfilePic, topicMessage, topicFollow/topicUnfollow.
  • psf-memo-db already has LevelDB stores for all of those actions and raw /level/* CRUD routes.
  • Client already supports: posting, replying, setting name, and the like/tip broadcast UI.
  • Main gaps: client UI for setting profile text/picture and follow/unfollow; high-level read APIs for like counts, follow state, topic feeds, polls, and mutes.

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Architecture constraints

• Identity/auth: the auto-generated HD wallet (12-word mnemonic) persisted in browser Local Storage by the existing React app is the Memo identity.
• Write path: broadcasting is done via minimal-slp-wallet.sendOpReturn().
  • Correct public API: await wallet.sendOpReturn(message, prefix, bchOutput).
  • prefix = '6d02' posts a memo; other action bytes replace 02.
  • Binary payloads (txid 32 bytes, address hash 20 bytes, topic/poll text) must be encoded correctly.
• Read path: psf-memo-db REST API (/posts/*, /profile/*, /level/*). API changes are in scope for specs.
• Indexer path: psf-memo-indexer scans blocks and mempool for Memo OP_RETURN outputs and writes structured records to psf-memo-db.
• The write path (broadcast), indexer path, and read path (DB) are asynchronous: a broadcasted action becomes visible only after confirmation + indexing.

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Memo protocol action codes

Reference: https://memo.sv/protocol (Wayback snapshot 2025-12-15)

Action byte	Meaning	Payload
0x6d01	Set name	name (≤ 217 bytes)
0x6d02	Post memo	message (≤ 217 bytes)
0x6d03	Reply to memo	txhash (32 bytes) + message (≤ 184 bytes)
0x6d04	Like / tip memo	txhash (32 bytes)
0x6d05	Set profile text	message (≤ 217 bytes)
0x6d06	Follow user	address (20 bytes)
0x6d07	Unfollow user	address (20 bytes)
0x6d0a	Set profile picture	url (≤ 217 bytes)
0x6d0b	Repost memo	txhash (32 bytes) + message (≤ 184 bytes) — planned
0x6d0c	Post topic message	topic_name + message (combined ≤ 214 bytes)
0x6d0d	Topic follow	topic_name
0x6d0e	Topic unfollow	topic_name
0x6d10	Create poll	poll_type (1) + option_count (1) + question (≤ 209 bytes)
0x6d13	Add poll option	poll_txhash (32) + option (≤ 184 bytes)
0x6d14	Poll vote	poll_txhash (32) + comment (≤ 184 bytes)
0x6d16	Mute user	address (20 bytes)
0x6d17	Unmute user	address (20 bytes)
0x6d24	Send money	address (20) + message (≤ 194 bytes)
0x6d30	Sell tokens	MIP-0009 token exchange
0x6d31	Token buy offer	MIP-0009 token exchange
0x6d32	Attach token sale signature	MIP-0009 token exchange
0x6d35	Pin token post	MIP-0009 token exchange — planned

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Component legend

Code	Component	Typical changes
C	psf-memo-client	React components, services, pages, unit/acceptance tests
I	psf-memo-indexer	Memo action handler, parser support, filter logic
D	psf-memo-db	LevelDB store, REST route, query adapter, tests

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Tier P0 — Already shipped to master

#	Feature	Memo action	Components	Status
0.1	Post a Memo	0x6d02	C, I, D	✅
0.2	Set display name	0x6d01	C, I, D	✅
0.3	Reply to a Memo	0x6d03	C, I, D	✅
0.4	Efficient post pagination	read	D, I	✅

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Tier P1 — Core social verbs (close the read loop)

These features already have indexer storage and (for like/tip) client broadcast. The remaining work is exposing the read side in psf-memo-db and adding/editing the client UI.

#	Feature	Memo action	Components	Status	Next work
1.1	Like / tip a Memo — read side	0x6d04	D	✅	likeCount returned on /posts/* and /posts/:txid/thread
1.2	Like / tip a Memo — client display	0x6d04	C	✅	Feed/Profile/Thread read likeCount from API instead of defaulting to 0
1.3	Set profile text (bio)	0x6d05	C	✅	C: "Set Bio" UI on Account page broadcasts 0x6d05 (217-byte limit)
1.4	Set profile picture	0x6d0a	C, I, D	✅	C: "Set Avatar URL" UI broadcasts 0x6d0a (217-byte limit); I/D already read
1.5	Follow a user	0x6d06	C, I, D	✅	C: follow button on profile; D: follow state + following/followers lists
1.6	Unfollow a user	0x6d07	C, I, D	✅	C: unfollow button; D: follow state

Priority order within P1

1. Like / tip a Memo — read side ✅ DONE.
2. Like / tip a Memo — client display ✅ DONE. The feed, profile, and thread views now read likeCount from the API (profile shows a read-only like button).
3. Set profile text ✅ DONE. Account page "Set Bio" UI broadcasts 0x6d05 with a 217-byte limit and byte counter (task set-bio).
4. Set profile picture ✅ DONE. Account page "Set Avatar URL" UI broadcasts 0x6d0a with a 217-byte limit and byte counter (task set-avatar-url).
5. Follow / Unfollow user ✅ DONE. Profile page Follow/Unfollow button broadcasts 0x6d06/0x6d07; DB exposes follow state and following/followers lists (task follow-user).

Like / tip details

• The like action carries the liked post txid (32 bytes). A pure like has no BCH output to the author; a tip adds a P2PKH output paying the author.
• psf-memo-indexer stores each like in likesDb and records tip (sats) when the like tx pays the author.
• psf-memo-db aggregates likesDb into per-post likeCount in /posts/recent, /posts/by/:addr, and /posts/:txid/thread responses.
• The client already has MemoLike, LikeTipPage, LikeButton, and LikeTipModal; the feed/profile/thread views now read likeCount from the API (profile renders a read-only LikeButton).

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Tier P2 — Topics

Topics add a second feed axis. The indexer already stores topic messages and follows in roomsDb; the DB and client need query/render support.

#	Feature	Memo action	Components	Status
2.1	Topic list / discovery	read	D, C	✅
2.2	Topic feed page	read	D, C	✅
2.3	Post a topic message	0x6d0c	C, I, D	🟡 spec'd → coder (task topic-actions)
2.4	Follow a topic	0x6d0d	C, I, D	🟡 spec'd → coder (task topic-actions)
2.5	Unfollow a topic	0x6d0e	C, I, D	🟡 spec'd → coder (task topic-actions)

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Tier P3 — Polls

Polls require a new data model and rendering. The indexer has no handler yet.

#	Feature	Memo action	Components	Status
3.1	Create a poll	0x6d10	C, I, D	🔴 missing
3.2	Add a poll option	0x6d13	C, I, D	🔴 missing
3.3	Vote in a poll	0x6d14	C, I, D	🔴 missing

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Tier P4 — Moderation

#	Feature	Memo action	Components	Status
4.1	Mute a user	0x6d16	C, D	🔴 missing
4.2	Unmute a user	0x6d17	C, D	🔴 missing

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Tier P5 — Money & token exchange

#	Feature	Memo action	Components	Status
5.1	Send money with memo	0x6d24	C	🔴 missing
5.2	Token sell offer	0x6d30 (MIP-0009)	C, I, D	🔴 missing
5.3	Token buy offer	0x6d31 (MIP-0009)	C, I, D	🔴 missing
5.4	Attach token sale signature	0x6d32 (MIP-0009)	C, I, D	🔴 missing
5.5	Pin token post	0x6d35 (MIP-0009)	C, I, D	🔴 missing

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Tier P6 — Advanced social & discovery (later)

#	Feature	Components	Notes
6.1	Repost a memo	C, I, D	0x6d0b is marked planned in the protocol
6.2	Ranked feed	C, D	memo.cash "ranked" post ordering
6.3	Notifications	C, D	replies / likes / follows to my posts
6.4	Search	C, D	posts / profiles / topics
6.5	Tags / hashtags	C, D	link + filter by tag
6.6	Following feed	C, D	feed filtered to followed users

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Suggested next spec

Post a topic message / Follow a topic / Unfollow a topic (P2.3 / P2.4 / P2.5):

• psf-memo-client: add a topic post composer and topic follow/unfollow buttons on the topic feed page that broadcast 0x6d0c / 0x6d0d / 0x6d0e.
• psf-memo-db: expose topic follow state and a topic's followers list.
• The indexer already stores topic messages and follows in roomsDb; the missing pieces are the client write path and the DB read side for follows.

Topic payloads (UTF-8, no cashaddr conversion)

Unlike follow/unfollow user, topic actions carry plain UTF-8 text (the topic name and, for 0x6d0c, the message). No bch-js cashaddr conversion is needed for topics. The 0x6d0c topic message payload is topic_name + message with a combined limit of 214 bytes; 0x6d0d / 0x6d0e carry only the topic name.

This is the next smallest end-to-end win after the topic list/feed read side closed.

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Notes for future cycles

• Broadcast result (txid) is returned immediately; the action appears in the feed only after block confirmation + indexing. Specs must reflect this async visibility.
• Mutations/specs are Gherkin feature files under per-component specs/ in the format defined by github.com/unclebob/Acceptance-Pipeline-Specification.
• Root specs/ contains this backlog and cross-component architecture notes.

Completed fixes (not roadmap features)

• ZMQ-mode DB backups (2026-08-28, task zmq-db-backups): the block indexer only created zip backups during IBD; the ZMQ live loop never called backupDb(). Fixed by centralizing the height % epoch === 0 decision in a BackupDb.maybeBackupDb use case called from both the IBD and ZMQ paths. Spec: psf-memo-indexer/specs/zmq-mode-db-backups.feature.