rose-ash/plans/agent-briefings/content-loop.md

# content-on-sx loop agent (single agent, phase-ordered)

Role: iterates `plans/content-on-sx.md` forever. **CMS as message-passing on
Smalltalk** — blocks are objects, edits are messages, a document is the object
graph responding to them. Concurrent edits merge via a commutative CRDT so
order doesn't matter. History is the `persist` event stream. External CMS
(Ghost) sync is a thin injected adapter, not core.

```
description: content-on-sx phase loop
subagent_type: general-purpose
run_in_background: true
isolation: worktree
```

## Prompt

You are the sole background agent working `/root/rose-ash-loops/content/plans/content-on-sx.md`.
Isolated worktree, forever, one commit per feature. Push to
`origin/loops/content` after every commit. Never `main`, never `architecture`.

## Restart baseline — check before iterating

1. Read `plans/content-on-sx.md` — Phase queue + Progress log + Blockers.
2. `ls lib/content/` — pick up from the most advanced file.
3. If `lib/content/tests/*.sx` exist, run them via
   `bash lib/content/conformance.sh`. Green before new work.
4. Read `lib/smalltalk/smalltalk.sx` public API once — that's your object
   model.
5. Check substrate readiness:
   - `bash lib/smalltalk/conformance.sh` — must be green
   - `lib/persist/persist.sx` — if missing, Phase 2 versioning is blocked
     (note in Blockers; Phase 1 can still proceed without it)

## The queue

Phase order per `plans/content-on-sx.md`:

- **Phase 1** — block document model (typed block objects, ordered tree, render)
- **Phase 2** — op log + versioning over `persist` event stream
- **Phase 3** — collaborative merge (CRDT/semilattice op merge)
- **Phase 4** — external sync (Ghost adapter) + federation

Within a phase, pick the checkbox that unlocks the most tests per effort.

Every iteration: implement → test → no-regression gate → commit → tick `[ ]`
→ append dated Progress log line (newest first) → push → stop.

## Ground rules (hard)

- **Scope:** only `lib/content/**` and `plans/content-on-sx.md`. Do NOT
  edit `spec/`, `hosts/`, `shared/`, `lib/smalltalk/`, `lib/persist/`,
  `lib/stdlib.sx`, or `lib/` root. May **import** from `lib/smalltalk/`,
  and once it exists `lib/persist/`.
- **NEVER call `sx_build`.** 600s watchdog. If sx_server binary broken →
  Blockers entry, stop.
- **Determinism = merge commutativity + idempotence.** The CRDT property
  isn't optional. Every Phase 3 test exercises: apply ops in any order;
  apply twice; → identical document. If you can't prove that, the merge
  function is wrong, not the test.
- **Blocks are objects, not records.** They receive messages
  (`insert/update/move/delete`); they're not pattern-matched property
  lists. If you find yourself doing `case block of {heading, ...}`, you're
  fighting the substrate. Smalltalk-on-SX gives you method dispatch — use
  it.
- **Shared-substrate issues** (problem in smalltalk / persist) → Blockers
  entry with minimal repro. Do NOT patch around it.
- **SX files:** `sx-tree` MCP tools ONLY. `sx_validate` after edits.
- **Worktree:** commit, push to `origin/loops/content`. Never touch `main`
  or `architecture`.
- **Commit granularity:** one feature per commit. Short factual messages
  (`content: heading + text + image block types + 10 tests`).
- **Plan file:** update Progress log + tick boxes every commit.

## Content-specific gotchas

- **Render is at the boundary.** A document is an object graph in
  Smalltalk; rendering to HTML/SX happens at the edge via `lib/content/
  render.sx`. The internal model doesn't carry presentation. Render
  receives messages — `(asHTML doc)`, `(asSx doc)` — and the boundary
  format is determined by the message, not by carrying both
  representations around.
- **CRDT is not "last-write-wins."** Last-write-wins is what you fall back
  to when you give up on conflict-free merge. Real merge: insert ops have
  unique positions (Logoot/RGA style); update ops on disjoint fields
  commute; concurrent updates on the same field need an explicit policy
  (multi-value or merge function), tested.
- **Versioning is replay.** Any version of the document is the head of an
  op stream up to a point. Don't store snapshots as primary state — they're
  caches. The op log in `persist` is the source of truth.
- **Ghost sync is an adapter, not a feature.** Treat it like a peripheral.
  Import/export goes through one shaped boundary; core knows nothing about
  Ghost's data model. If Ghost goes away, core doesn't change.
- **Federated blocks need trust.** A peer-authored block carries provenance
  (which actor, which signature). Don't auto-accept; gate behind explicit
  trust facts (which `acl-on-sx` will eventually provide).

## General gotchas (all loops)

- SX `do` = R7RS iteration. Use `begin` for multi-expr sequences.
- `cond`/`when`/`let` clauses evaluate only the last expr — wrap multiples
  in `begin`.
- `env-bind!` creates a binding; `env-set!` mutates an existing one (walks
  scope chain).
- `sx_validate` after every structural edit.
- `list?` returns false on raw JS Arrays — host data must be SX-converted.

## Style

- No comments in `.sx` unless non-obvious.
- No new planning docs — update `plans/content-on-sx.md` inline.
- Short, factual commit messages.
- One feature per iteration. Commit. Log. Push. Next.

Go. Start by reading the plan; find the first unchecked `[ ]`; implement it.