psf-memo/specs/feature-backlog.md

psf-memo — Feature Backlog

Status: DRAFT — refreshed 2026-09-03. Owner: specifier. Last updated: 2026-09-03

---

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.

---

Current direction

Core functionality is implemented and shipped. For the foreseeable future the focus is front-end improvements to psf-memo-client (the React SPA).

• All previously listed roadmap features (P0–P6) have been removed from this backlog.
• New work should target the client: UI/UX polish, accessibility, performance, responsiveness, state handling, error surfacing, and any other front-end improvements.
• A single user-facing feature may still touch more than one component; call out all affected components in the task description and in the handoff.

Recently completed

• Mute feed filtering (2026-09-04): muting a profile now hides that profile's content from the viewer's recent feed, topic feed, search results, and notifications. The psf-memo-db API filters server-side given the viewer's address (passed by the client as a viewer query param); filtering is not optimistic — a mute takes effect once the mute tx is indexed, and unmuting restores content once indexed. Shared loadMutedAddrs/isMutedPost helper in psf-memo-db/src/adapters/lib/muted-posts.js deduplicates the per-adapter lookup. Spec: psf-memo-client/specs/mute-feed-filtering.feature. Merged to master at 3992395.
• Binary hash160 broadcast payloads (2026-09-04): client follow/unfollow and mute/unmute now broadcast the target's raw 20-byte hash160 as the OP_RETURN payload, built as a browser-safe Uint8Array from the hexToBytes helper instead of Node's Buffer global (which crashed in a real browser with Buffer is not defined). Follow/mute/unfollow/unmute were consolidated onto a shared MemoStateAction base. Spec: psf-memo-client/specs/binary-payload-broadcast.feature. Merged to master at 984e691.
• Page size 50 (2026-09-04): every paginated page in the client now requests 50 items per page instead of 100 to cut payload size and improve page load times. Covers the recent feed, following feed, topic feed, notifications, search, profile, and recent profiles pages. Pagination Previous/Next controls were also added to the search, profile, and recent-profiles pages (which previously had none), and the paginated page controllers were refactored onto a shared PaginatedPage base plus RecentProfilesPage. Spec: psf-memo-client/specs/page-size.feature. Merged to master at cfe6711.
• YouTube embed (2026-09-04): posts whose text contains a YouTube link (youtube.com/watch?v=… or youtu.be/…) render an embedded player instead of the raw URL; surrounding text is preserved; non-embeddable URLs stay plain text. Client-only rendering feature. Spec: psf-memo-client/specs/youtube-embed.feature. Merged to master at b63019c.

---

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 was derived from the protocol spec plus an audit of the existing mono-repo code.

---

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.

---

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

---

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

---

Next up: feed query performance

GET /posts/recent (and the other paginated feeds) is slow at 1.3M posts because list-recent-posts.js does two full scans on every request:

• countTopLevelPosts() iterates the ENTIRE postHeights index to compute the total/hasMore pagination field.
• buildReplyCountMap() scans ALL postChildren entries to build a global reply-count map.

Planned optimization (decision: capped scan, keep it simple):

• Replace the global buildReplyCountMap() with per-page-txid reply counting (like countLikesForTxids already does) — only count replies for the ~50 posts on the page.
• Cap the total scan to the last N posts / last N blocks so hasMore still works for the first pages without walking all 1.3M entries.

Affected components: psf-memo-db (feed use cases + post-query adapter).

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.