/brain-derive

/mos:brain-derive

Force-refresh BRAIN.md per section via the Brain derivation pipeline. This is the manual knob users reach for when the automatic triggers (hash-change queue drain, session-start staleness scan) are not enough because they want to inspect explicitly, or the room has no recent regeneration activity.

Modes

• /mos:brain-derive <section> -- derive one section
• /mos:brain-derive --all -- derive every active section in the current room
• /mos:brain-derive <section> --cross-room -- add structural cross-room contradiction scan for that one section
• /mos:brain-derive --all --cross-room -- most expensive; cross-room scan on every section
• Append --dry-run to any mode above to preview targets + cost without firing any Brain calls or writing BRAIN.md

Output

Shape E Action Report (Canon Part 3 UI Ruling System; same structure as /mos:diagnostics from Phase 88.6 Plan 02). Five summary rows plus a PER SECTION breakdown plus a NEXT action footer:

• Sections derived: N / M
• Schema gates: passed X / failed Y
• Cross-room: Z contradictions surfaced / scanned rooms
• Brain offline: A sections skipped (rate-limited flag if applicable)
• Cost tokens: ~T

When there are more than 3 target sections, per-section progress streams to stderr as each completes: [1/7] market-analysis: derived. The final Shape E report renders to stdout at the end.

Graceful degradation

• Brain offline from start: single-line "Brain offline, no derivation possible" message, zero derivations, exit 0 (soft-fail). The user has not done anything wrong; BRAIN.md is enrichment, not a gate.
• Rate-limited mid-batch: the first rate_limited result stops further Brain calls. Every remaining section is recorded as skipped with reason rate_limited. The rendered report carries the flag and the NEXT footer suggests retrying in a few minutes.
• Schema gate rejection on one section: other sections still derive. The failed section appears in the PER SECTION block with the schema violation summary. The command does NOT attempt to force-write a schema-invalid BRAIN.md.
• Invalid section name: exit 1 with a pointer to the active room and a hint to list sections.
• No active room: exit 1 with "Set one with /mos:rooms switch ".

Canon references

• Canon Part 3 (Tri-Context Decision Gate): output uses the Shape E Action Report body shape so the user sees a LOCAL + BRAIN snapshot of what was derived this run.
• Canon Part 7 (Reuse Before Build): the command wraps the existing deriveSection entry point (Plan 90-01) and the cross-room aggregator (Plan 90-06). No new derivation logic is introduced at the command layer.
• Canon Part 8 (Graph Boundary): the command adds zero net new Brain surface. Every Brain call still routes through deriveSection which has its chokepoint (buildBrainQueryContext), the prompt-builder allow-list schema, the invariants body scan, and the cross-room sanitize + JSON.stringify audit. The dispatcher only sequences those calls and renders results.

Invocation

Run the dispatcher via Bash:

node ${CLAUDE_PLUGIN_ROOT}/scripts/brain-derive-command.cjs $ARGUMENTS

Examples

/mos:brain-derive market-analysis
/mos:brain-derive --all
/mos:brain-derive --all --cross-room
/mos:brain-derive market-analysis --dry-run
/mos:brain-derive --all --cross-room --dry-run

Exit codes

Exit	Meaning
0	Success (including Brain-offline soft-fail and all partial-completion paths)
1	Invocation error: no active room, invalid section name, or missing arguments

Cross-surface adaptation

• CLI: full power. Slash command resolves via Claude Code's plugin hook substrate and runs the dispatcher through the Bash tool. Shape E report renders in the terminal.
• Desktop: the same slash command runs when the plugin is connected. Larry may narrate the result conversationally; the underlying dispatcher is identical.
• Cowork: same as CLI. Team members see the regenerated BRAIN.md through the shared 00_Context/ snapshot on their next session-start.

No surface-specific code exists anywhere in the dispatcher.