diff --git a/cmd/projax-snapshot/main.go b/cmd/projax-snapshot/main.go
new file mode 100644
index 0000000..3eb98c3
--- /dev/null
+++ b/cmd/projax-snapshot/main.go
@@ -0,0 +1,349 @@
+// projax-snapshot dumps the current projax.items + projax.item_links state
+// to a JSON file so the mBrian-side migration script (m/mBrian#73) can
+// consume it. Read-only; no schema changes; idempotent across runs.
+//
+// Phase 6 Slice 0 — first projax-side step in the mBrian-backend migration.
+// See docs/plans/mbrian-backend-migration.md §7 + §8 for the surrounding
+// context. The file shape is documented in the m/mBrian#73 issue body
+// (the two-pass node-then-edge layout the migration script expects).
+//
+// Usage:
+//
+//	projax-snapshot                          # write ./projax_snapshot.json
+//	projax-snapshot --out path/to/file.json  # custom output path
+//
+// Env: PROJAX_DB_URL or SUPABASE_DATABASE_URL — direct postgres URL into
+// msupabase (same conventions as the main projax binary).
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"os"
+	"sort"
+	"time"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// Snapshot is the top-level JSON shape mBrian-side consumes.
+type Snapshot struct {
+	Version    string      `json:"version"`     // doc-evolution marker; bump on shape changes
+	GeneratedAt time.Time  `json:"generated_at"`
+	GitCommit  string      `json:"git_commit,omitempty"` // optional build-time injection
+	Items      []Item      `json:"items"`
+	Links      []ItemLink  `json:"links"`
+	SpotChecks []SpotCheck `json:"spot_checks"` // 5 representative items per m/mBrian#73 §3
+}
+
+// Item mirrors every column on projax.items as of this commit. Field
+// order matches the SQL projection; types are JSON-friendly (uuid →
+// string, jsonb → map). Anything nullable surfaces as omitempty / *T.
+type Item struct {
+	ID                string         `json:"id"`
+	Kind              []string       `json:"kind"`
+	Title             string         `json:"title"`
+	Slug              string         `json:"slug"`
+	Paths             []string       `json:"paths"`
+	ParentIDs         []string       `json:"parent_ids"`
+	ContentMD         string         `json:"content_md"`
+	Aliases           []string       `json:"aliases"`
+	Metadata          map[string]any `json:"metadata"`
+	Status            string         `json:"status"`
+	Pinned            bool           `json:"pinned"`
+	Archived          bool           `json:"archived"`
+	StartTime         *time.Time     `json:"start_time,omitempty"`
+	EndTime           *time.Time     `json:"end_time,omitempty"`
+	Tags              []string       `json:"tags"`
+	Management        []string       `json:"management"`
+	Public            bool           `json:"public"`
+	PublicDescription string         `json:"public_description,omitempty"`
+	PublicLiveURL     string         `json:"public_live_url,omitempty"`
+	PublicSourceURL   string         `json:"public_source_url,omitempty"`
+	PublicScreenshots []string       `json:"public_screenshots,omitempty"`
+	TimelineExclude   []string       `json:"timeline_exclude,omitempty"`
+	CreatedAt         time.Time      `json:"created_at"`
+	UpdatedAt         time.Time      `json:"updated_at"`
+}
+
+// ItemLink mirrors projax.item_links. ref_type values become projax-*
+// edge rel names on the mBrian side; the payload lands in edges.metadata
+// per the issue body §1.
+type ItemLink struct {
+	ID        string         `json:"id"`
+	ItemID    string         `json:"item_id"`
+	RefType   string         `json:"ref_type"`
+	RefID     string         `json:"ref_id"`
+	Rel       string         `json:"rel"`
+	Note      *string        `json:"note,omitempty"`
+	Metadata  map[string]any `json:"metadata"`
+	EventDate *time.Time     `json:"event_date,omitempty"`
+	CreatedAt time.Time      `json:"created_at"`
+}
+
+// SpotCheck names one of the 5 representative items the mBrian-side
+// script verifies post-migration. The reason text is mirrored from
+// m/mBrian#73 §3 so future readers don't need to cross-reference.
+type SpotCheck struct {
+	ItemID string `json:"item_id"`
+	Slug   string `json:"slug"`
+	Title  string `json:"title"`
+	Reason string `json:"reason"`
+}
+
+func main() {
+	out := flag.String("out", "projax_snapshot.json", "output JSON path")
+	flag.Parse()
+
+	dbURL := os.Getenv("PROJAX_DB_URL")
+	if dbURL == "" {
+		dbURL = os.Getenv("SUPABASE_DATABASE_URL")
+	}
+	if dbURL == "" {
+		die("set PROJAX_DB_URL or SUPABASE_DATABASE_URL")
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+	pool, err := pgxpool.New(ctx, dbURL)
+	if err != nil {
+		die("pool: %v", err)
+	}
+	defer pool.Close()
+
+	items, err := loadItems(ctx, pool)
+	if err != nil {
+		die("load items: %v", err)
+	}
+	links, err := loadLinks(ctx, pool)
+	if err != nil {
+		die("load links: %v", err)
+	}
+	spots := pickSpotChecks(items, links)
+
+	snap := Snapshot{
+		Version:     "1",
+		GeneratedAt: time.Now().UTC(),
+		Items:       items,
+		Links:       links,
+		SpotChecks:  spots,
+	}
+
+	buf, err := json.MarshalIndent(snap, "", "  ")
+	if err != nil {
+		die("marshal: %v", err)
+	}
+	if err := os.WriteFile(*out, buf, 0644); err != nil {
+		die("write %s: %v", *out, err)
+	}
+	fmt.Fprintf(os.Stderr,
+		"wrote %s — %d items, %d links, %d spot-checks\n",
+		*out, len(items), len(links), len(spots))
+}
+
+func loadItems(ctx context.Context, pool *pgxpool.Pool) ([]Item, error) {
+	rows, err := pool.Query(ctx, `
+SELECT id, kind, title, slug, paths, parent_ids, content_md, aliases,
+       metadata, status, pinned, archived, start_time, end_time,
+       tags, management,
+       public, coalesce(public_description, ''),
+       coalesce(public_live_url, ''),
+       coalesce(public_source_url, ''),
+       public_screenshots,
+       timeline_exclude,
+       created_at, updated_at
+FROM projax.items
+WHERE deleted_at IS NULL
+ORDER BY paths NULLS FIRST, slug`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := []Item{}
+	for rows.Next() {
+		var it Item
+		if err := rows.Scan(
+			&it.ID, &it.Kind, &it.Title, &it.Slug, &it.Paths, &it.ParentIDs,
+			&it.ContentMD, &it.Aliases, &it.Metadata, &it.Status, &it.Pinned, &it.Archived,
+			&it.StartTime, &it.EndTime, &it.Tags, &it.Management,
+			&it.Public, &it.PublicDescription, &it.PublicLiveURL, &it.PublicSourceURL,
+			&it.PublicScreenshots, &it.TimelineExclude, &it.CreatedAt, &it.UpdatedAt,
+		); err != nil {
+			return nil, err
+		}
+		// Normalise empty slices: pgx hands back nil for empty array
+		// columns, which renders as `null` in JSON. Coerce to [] for
+		// downstream-script ergonomics.
+		if it.Kind == nil {
+			it.Kind = []string{}
+		}
+		if it.Paths == nil {
+			it.Paths = []string{}
+		}
+		if it.ParentIDs == nil {
+			it.ParentIDs = []string{}
+		}
+		if it.Aliases == nil {
+			it.Aliases = []string{}
+		}
+		if it.Tags == nil {
+			it.Tags = []string{}
+		}
+		if it.Management == nil {
+			it.Management = []string{}
+		}
+		if it.PublicScreenshots == nil {
+			it.PublicScreenshots = []string{}
+		}
+		if it.TimelineExclude == nil {
+			it.TimelineExclude = []string{}
+		}
+		if it.Metadata == nil {
+			it.Metadata = map[string]any{}
+		}
+		out = append(out, it)
+	}
+	return out, rows.Err()
+}
+
+func loadLinks(ctx context.Context, pool *pgxpool.Pool) ([]ItemLink, error) {
+	rows, err := pool.Query(ctx, `
+SELECT id, item_id, ref_type, ref_id, rel, note, metadata,
+       event_date, created_at
+FROM projax.item_links
+ORDER BY item_id, ref_type, created_at`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	out := []ItemLink{}
+	for rows.Next() {
+		var l ItemLink
+		if err := rows.Scan(
+			&l.ID, &l.ItemID, &l.RefType, &l.RefID, &l.Rel, &l.Note,
+			&l.Metadata, &l.EventDate, &l.CreatedAt,
+		); err != nil {
+			return nil, err
+		}
+		if l.Metadata == nil {
+			l.Metadata = map[string]any{}
+		}
+		out = append(out, l)
+	}
+	return out, rows.Err()
+}
+
+// pickSpotChecks selects the 5 representative items the mBrian-side
+// migration script verifies post-migration, per m/mBrian#73 §3:
+//
+//  1. A simple root area (dev).
+//  2. A single-parent project (dev.paliad — or whichever single-parent
+//     project we can find).
+//  3. A multi-parent project (any item with >1 parent_id).
+//  4. A project with a caldav-list link.
+//  5. A project with public=true and public_description / public_live_url
+//     populated.
+//
+// Failures to find any one of the 5 are non-fatal — the SpotChecks slice
+// just shrinks. mBrian-side script logs whatever's missing.
+func pickSpotChecks(items []Item, links []ItemLink) []SpotCheck {
+	byID := map[string]*Item{}
+	for i := range items {
+		byID[items[i].ID] = &items[i]
+	}
+	caldavItems := map[string]bool{}
+	for _, l := range links {
+		if l.RefType == "caldav-list" {
+			caldavItems[l.ItemID] = true
+		}
+	}
+	out := []SpotCheck{}
+
+	// 1. Root area "dev" if present.
+	for _, it := range items {
+		if it.Slug == "dev" && len(it.ParentIDs) == 0 {
+			out = append(out, SpotCheck{
+				ItemID: it.ID, Slug: it.Slug, Title: it.Title,
+				Reason: "root area (dev) — verify type=['project'] + metadata.projax.kind='area' round-trip",
+			})
+			break
+		}
+	}
+
+	// 2. Single-parent project — prefer dev.paliad if present, else any.
+	added2 := false
+	for _, it := range items {
+		if it.Slug == "paliad" && len(it.ParentIDs) == 1 {
+			out = append(out, SpotCheck{
+				ItemID: it.ID, Slug: it.Slug, Title: it.Title,
+				Reason: "single-parent project (dev.paliad) — verify one child_of edge",
+			})
+			added2 = true
+			break
+		}
+	}
+	if !added2 {
+		for _, it := range items {
+			if len(it.ParentIDs) == 1 && !containsString(it.Kind, "mai-managed") {
+				out = append(out, SpotCheck{
+					ItemID: it.ID, Slug: it.Slug, Title: it.Title,
+					Reason: "single-parent project — verify one child_of edge",
+				})
+				break
+			}
+		}
+	}
+
+	// 3. Multi-parent project — any item with cardinality(parent_ids) > 1.
+	for _, it := range items {
+		if len(it.ParentIDs) > 1 {
+			out = append(out, SpotCheck{
+				ItemID: it.ID, Slug: it.Slug, Title: it.Title,
+				Reason: fmt.Sprintf("multi-parent project (%d parents) — verify all child_of edges land", len(it.ParentIDs)),
+			})
+			break
+		}
+	}
+
+	// 4. Project with a caldav-list link.
+	for _, it := range items {
+		if caldavItems[it.ID] {
+			out = append(out, SpotCheck{
+				ItemID: it.ID, Slug: it.Slug, Title: it.Title,
+				Reason: "caldav-list-linked project — verify edges.metadata.url payload round-trip",
+			})
+			break
+		}
+	}
+
+	// 5. Project with public=true + public_description populated.
+	for _, it := range items {
+		if it.Public && it.PublicDescription != "" {
+			out = append(out, SpotCheck{
+				ItemID: it.ID, Slug: it.Slug, Title: it.Title,
+				Reason: "public-listing project — verify metadata.projax.public.* bundle preserved for flexsiebels renderer",
+			})
+			break
+		}
+	}
+
+	// Stable order for deterministic output.
+	sort.SliceStable(out, func(i, j int) bool { return out[i].Slug < out[j].Slug })
+	return out
+}
+
+func containsString(haystack []string, needle string) bool {
+	for _, s := range haystack {
+		if s == needle {
+			return true
+		}
+	}
+	return false
+}
+
+func die(format string, args ...any) {
+	fmt.Fprintf(os.Stderr, format+"\n", args...)
+	os.Exit(1)
+}
diff --git a/docs/plans/mbrian-backend-migration.md b/docs/plans/mbrian-backend-migration.md
new file mode 100644
index 0000000..637a6b9
--- /dev/null
+++ b/docs/plans/mbrian-backend-migration.md
@@ -0,0 +1,434 @@
+# mBrian-as-backend migration — Phase 6 design
+
+**Status**: Phase A design — re-baselined against live mBrian schema (2026-05-29).
+**Branch**: `mai/kahn/phase-6a-mbrian-design`.
+**Author**: kahn (inventor), 2026-05-29.
+**Source decision** (m, issue m/projax#5, 12:43 2026-05-29): Option A — full backend migration. *"I think we need the project-management element inside of mBrian for it to be the complete 2nd Brain experience. The data itself is not too important yet."*
+
+**m's overriding directive** (2026-05-29 via head): *"keep the database simple so it remains easily modifiable."*
+
+**Constraint**: data-loss tolerant on the 47 current `projax.items`.
+
+**m's answers on §10 (2026-05-29)**: every inventor pick confirmed.
+
+> Q1=reuse 'project' / Q2=(b) handler bridge / Q3=(a) clients projax-side / Q4=(a) file Gitea on m/mBrian via otto/head — m: *"mbrian must own the migration"* / Q5=(a) views stay projax-resident / Q6=(a) per-user slug / Q7=(a) hard-cut / Q8=(a) tags in metadata / Q9=(a) projax-side cycle detection / Q10=(a) keep projax MCP via adapter / Q11=keep `projax_origin` audit metadata.
+
+**Re-baseline note**: §3's original ask was built off a stale `db/001_initial_schema.sql` read. Head verified the live mBrian schema after m's answers. Three of the six asks (MB-A, MB-C, MB-D) turned out already-satisfied — `edges.metadata` exists since `db/010_flexsiebels_compat.sql`, `'project'` type exists since `db/033`, the per-user slug unique index ships in `db/001`. The remaining mBrian-side artifact is small. §3 + §8 now reflect that. The big shift: **mBrian owns the one-shot data-migration script** — that's what "mbrian must own the migration" means — while projax owns the read+write rewiring on its own side afterward.
+
+---
+
+## §1 — Diagnosis
+
+projax today stores its own structured data in `projax.items` + `projax.item_links` (msupabase, schema `projax`). It's a parallel knowledge surface to mBrian's main graph — both store nodes-with-content-and-edges, both speak SQL+jsonb, both ship MCP. The duplication has cost: project context (held by projax) is invisible to mBrian's reasoning paths; mBrian's relationship graph (held by mbrian) is invisible to projax's tile / timeline aggregations.
+
+m's call closes the gap by making mBrian canonical. Projax keeps its UI — the /views routes, the Tiles dashboard, the calendar grid, the timeline spine, the /tree forest, the just-shipped /views/{slug} family, and the system-view chrome — but every read and write goes through mBrian instead of `projax.items`. Same surface, single source.
+
+End-state contract:
+
+- One node graph. Every project, task-context, area, link bundle lives in `mbrian.nodes` + `mbrian.edges`.
+- projax's UI is a structured editor + aggregation surface over that graph (think paliad-shape views, mBrian-shape data).
+- mBrian's existing surfaces (the web editor, the trackers, the synthesis filings) keep working unchanged — projax data appears alongside everything else.
+- CalDAV / Gitea / mai.projects integrations stay projax-handled at the consumption layer; the items they hang off of live in mBrian.
+- The 47-item migration is one-shot. Anything lossy gets logged + flagged for manual repair; we don't preserve at all costs.
+
+---
+
+## §2 — Schema mapping (the load-bearing section)
+
+### Per-column map: `projax.items` → mBrian shape
+
+| projax column | mBrian destination | notes |
+|---|---|---|
+| `id` (uuid) | `nodes.id` | new uuids on migration; legacy ids never round-trip |
+| `kind` (text[]) | `nodes.type` | direct shape match; projax `'project'` becomes mBrian `'project'` (already in live schema, mig 033). **Areas keep `type=['project']` + `metadata.projax.kind='area'`** — per m's "keep the database simple" directive, no new mBrian type. Zero DDL. |
+| `title` | `nodes.title` | 1:1 |
+| `slug` | `nodes.slug` | mBrian = unique per user; projax = unique per parent — see §2.1 |
+| `paths` (text[]) | derived from `child_of` edges + `nodes.path` cache | DAG resolution via edge walk; see §2.2 |
+| `parent_ids` (uuid[]) | edges `(source=this, rel='child_of', target=parent)` | one edge per parent; preserves multi-parent |
+| `content_md` | `nodes.content_md` | 1:1 |
+| `aliases` (text[]) | `nodes.aliases` | 1:1 |
+| `metadata` (jsonb) | `nodes.metadata` | merge; projax metadata keeps its existing shape under a `projax` sub-key to avoid colliding with mBrian's metadata schema |
+| `status` (text) | `nodes.metadata.projax.status` | active/done/archived; mBrian's `archived` bool covers part of it but loses the active/done split |
+| `pinned` (bool) | `nodes.pinned` | 1:1 |
+| `archived` (bool) | `nodes.archived` | 1:1; status='archived' implies this too |
+| `start_time`, `end_time` (timestamptz) | `nodes.metadata.projax.start_time` / `end_time` | mBrian has no first-class start/end |
+| `tags` (text[]) | `nodes.metadata.projax.tags` | mBrian convention puts tags as separate `[tag]` nodes joined via `tagged` edges; we keep tags in metadata for the migration window then optionally re-shape — see Q8 |
+| `management` (text[]) | `nodes.metadata.projax.management` | mai/self/external/unmanaged — projax-specific concept; stays in metadata |
+| `public`, `public_description`, `public_live_url`, `public_source_url`, `public_screenshots` | `nodes.metadata.projax.public.{...}` | mBrian's `visibility` is a different model (personal/public/...); we keep projax's bundle in metadata so the flexsiebels portfolio renderer keeps working |
+| `timeline_exclude` (text[]) | `nodes.metadata.projax.timeline_exclude` | projax-only concept |
+| `created_at` | `nodes.created_at` | 1:1 |
+| `updated_at` | `nodes.updated_at` | trigger-maintained on both sides |
+| `deleted_at` | `nodes.deleted_at` | 1:1 |
+
+### §2.1 — Slug uniqueness (settled)
+
+projax today enforces slug uniqueness **per parent**. mBrian's live schema has `CREATE UNIQUE INDEX idx_nodes_slug ON mbrian.nodes (user_id, slug)` — uniqueness **per user**. Per m's Q6=(a), projax adopts mBrian's model: one `paliad` node total, connected to both `dev` and `work` via two `child_of` edges. The DAG-as-multiple-paths view is a render-time concept; the storage is one node.
+
+projax handlers' itemwrite validator (Phase 5c) loses its per-parent slug rule, gains a per-user check (against the projax-managed subset of nodes). This is **stricter** — m can't have two different "paliad" projects under different roots. Settled per m's answer.
+
+**Pre-migration dedup**: the 47-item migration script (which lives mBrian-side, see §3+§7) scans for slug collisions across the projax dataset and folds collisions into one node with multiple `child_of` edges. Skip-with-log on anything weirder.
+
+### §2.2 — paths array vs single path
+
+projax's `paths text[]` is computed from `parent_ids` (one path per ancestor lineage). mBrian's `path text` is a single denormalized cache; the canonical structure is `child_of` edges.
+
+For projax UI to keep showing multi-paths ("Also at: work.paliad"), the store-adapter layer (§4) re-derives `paths[]` from the edge graph on each fetch. Cheap at m's scale (≤200 nodes); cache lightly if profiling bites.
+
+### `projax.item_links` → mBrian edges
+
+Each `item_links` row becomes a mBrian edge with a typed `rel`. The `ref_id` semantics differ:
+
+| projax ref_type | mBrian shape | notes |
+|---|---|---|
+| `caldav-list` | edge `rel='projax-caldav-list'`, `metadata.url=...` | external URL — no target node exists; edge carries the URL in `note` or `metadata` |
+| `gitea-repo` | edge `rel='projax-gitea-repo'`, metadata={owner, repo} | same shape |
+| `gitea-issue` | edge `rel='projax-gitea-issue'`, metadata={owner, repo, number} | same |
+| `mai-project` | edge `rel='projax-mai-project'`, metadata={mai_project_id} | bridge for the Phase 1.5 bidirectional sync |
+| `mbrian-node` | edge `(source=this, rel='related_to', target=<mbrian uuid>)` | already mBrian — this becomes a regular node-to-node edge |
+| `url` | edge `rel='projax-url'`, metadata={url} | unstructured link |
+| `document`, `note` | edge `rel='projax-doc'`, metadata={...} | PER day-granular dated artifacts |
+
+mBrian edges support `note text` plus an `auto bool` flag. Both used by projax: `auto=false` for human-added links, `note` carries human annotation. The structured payload (URL, repo info, etc.) lands in a metadata jsonb that we add via a new `edges.metadata` column — see §3.
+
+### Open question on edge payloads
+
+mBrian's `edges` table today has no `metadata jsonb` column — only `rel`, `note`, `sort_order`, `node_id`, `auto`. For projax's typed external-ref payloads (caldav URLs, gitea repo names), we need either:
+- (a) Add `metadata jsonb` to `mbrian.edges` (mBrian-side schema work, see §3 Q-A).
+- (b) Use the `node_id` "complex edge" feature: the edge points at a third node that holds the metadata. Heavier per-link cost; one node per external ref.
+- (c) Stash structured payload inside `note text` as JSON. Hacky; loses index-ability.
+
+**Inventor pick: (a)** — adds one nullable column to `edges`, indexes optionally, keeps the simple shape and matches projax's existing item_links model.
+
+---
+
+## §3 — mBrian-side requirements (re-baselined against live schema)
+
+Head verified the live mBrian schema after m's answers. Three of the original six asks turned out already-satisfied. What's actually needed reduces to one [schema] convention node + ownership of the one-shot data-migration script. Per m's Q4=(a), this lands as a Gitea issue on `m/mBrian` with the "blocks projax phase 6" tag; head files it.
+
+### Already satisfied (no DDL needed)
+
+| original ask | live-schema status |
+|---|---|
+| MB-A — `edges.metadata jsonb` column | **Already exists** — added in `db/010_flexsiebels_compat.sql`: `ALTER TABLE mbrian.edges ADD COLUMN IF NOT EXISTS metadata jsonb NOT NULL DEFAULT '{}'` plus GIN `idx_edges_metadata`. Already used by mig 039/040. projax link payloads land here directly. |
+| MB-C — `'project'` type registration | **Already exists** — confirmed in `db/033` + inbox tests. m's Q1=(a) reuses it. |
+| MB-C — `'area'` type registration | **NOT needed** — per m's "keep the database simple," areas reuse `type=['project']` with `metadata.projax.kind='area'`. Zero DDL. |
+| MB-D — per-user slug uniqueness | **Already enforced** — `CREATE UNIQUE INDEX idx_nodes_slug ON mbrian.nodes (user_id, slug)` in `db/001`. Handles the bulk migration as-is, modulo the pre-write dedup pass in the script (§7). |
+| MB-E — read MCP coverage | **Confirmed** by head — type-array filter, edge query by `rel` + source/target, FTS search all present in mBrian's MCP today. Optional bulk "node + outbound edges" endpoint may improve adapter perf, but v1 ships without it. |
+| MB-F — write MCP coverage | **Confirmed** by head — create_node, update_node, soft-delete, create_edge, delete_edge all present. |
+
+### Remaining mBrian-side artifact
+
+**MB-B — projax-integration `[schema]` convention node.** One new mBrian node, no DDL. Lives under a new `[topic]` hub `projax-integration`. Documents:
+
+1. The projax edge relations: `child_of` (already in use everywhere), `projax-caldav-list`, `projax-gitea-repo`, `projax-gitea-issue`, `projax-mai-project`, `projax-url`, `projax-doc`. Each entry: rel name + the metadata jsonb shape (e.g. `projax-caldav-list` carries `{url: text}`).
+2. The projax type usage: `'project'` for both projects and areas; `metadata.projax.kind` distinguishes (`area` vs default `project`). `'mai-managed'` as a co-type marker for nodes mirroring `mai.projects` rows.
+3. The projax metadata shape: `metadata.projax.{status, tags, management, public, timeline_exclude, start_time, end_time, kind}` — the subset of projax columns that don't have a first-class mBrian counterpart.
+4. A pointer to `projax_origin` audit metadata (set per migrated node, per m's Q11=keep).
+
+mBrian-side coder writes this node by creating it via mBrian's editor or MCP. No migration file needed.
+
+### mBrian owns the data-migration script
+
+Per m's directive "mbrian must own the migration," the one-shot script that creates the 47 nodes + their edges lives in `m/mBrian` (likely `scripts/migrate-from-projax.ts` or similar — mBrian's stack picks). projax-side provides:
+
+- A frozen snapshot of `projax.items` + `projax.item_links` rows (CSV or JSON dump produced by a projax-side helper).
+- The mapping rules from §2 + §2.2 in a form mBrian-side can implement against (this plan doc is the canonical source).
+- A spot-check checklist (5 representative items) for post-migration validation.
+
+The script's blast radius lives on mBrian's side; projax-side blocks on its successful run before slice C kicks off.
+
+### Cross-repo coordination shape
+
+One Gitea issue on `m/mBrian` (filed by head), tagged "blocks projax phase 6". The issue body covers MB-B + script ownership + the snapshot-handoff protocol. Body draft delivered to head with this re-baseline (see Phase A workflow §14).
+
+---
+
+## §4 — projax-side read-path replacement
+
+The store package becomes a thin adapter over mBrian. Consumers stay shape-stable: `*store.Item` still exposes Kind / Title / Slug / Paths / ParentIDs / ContentMD / Aliases / Metadata / Status / Pinned / Archived / Tags / Management / Public* / TimelineExclude / etc. Internally those come from mBrian nodes + metadata + edge-walks.
+
+| projax call site | new implementation |
+|---|---|
+| `store.Store.ListAll(ctx)` | mBrian: `SELECT FROM mbrian.nodes WHERE 'projax' = ANY(metadata.projax_origin) ... ORDER BY title` (or via MCP `list_nodes`). Returns []*Item adapted from each node. |
+| `store.Store.GetByPath(ctx, path)` | resolve path → leaf node by walking `child_of` edges from the path's root segment; cache hits during render |
+| `store.Store.GetByID(ctx, id)` | direct mBrian fetch |
+| `store.Store.LinksByRefType(ctx, t)` | edge query `rel='projax-<t>'` over all projax-managed nodes |
+| `store.Store.AllTags(ctx)` | aggregate over `metadata.projax.tags` arrays across projax nodes |
+| `store.Store.MaiOrphans(ctx)` | mBrian: find projax-managed nodes with no `child_of` edge + `metadata.projax.management contains 'mai'` |
+| `store.Store.DatedLinks(ctx, id)` | edge query `rel IN ('projax-doc', 'projax-url')` for the node, filtered to those with `metadata.event_date` set |
+
+The aggregator (`internal/aggregate/`) doesn't see mBrian — it gets `[]*store.Item` from the adapter. CalDAV + Gitea external fetches stay where they are.
+
+Views (Phase 5j `projax.views` table) decision point — see Q5.
+
+### Adapter layer surface
+
+```go
+package store
+
+type Store struct {
+    mb *mbrian.Client  // MCP-style client or direct SQL
+}
+
+func (s *Store) ListAll(ctx context.Context) ([]*Item, error) { ... }
+// every existing method keeps its signature; bodies rewrite to mBrian calls
+```
+
+The Item struct stays unchanged. Tests against the adapter assert "given this mBrian state, ListAll returns these items". Existing aggregator + handler tests stay green because they only see `*Item`.
+
+---
+
+## §5 — projax-side write-path replacement
+
+Every projax write rewires to mBrian.
+
+| projax handler | new behaviour |
+|---|---|
+| `POST /i/{path}` (detail edit, `handleDetailWrite`) | mBrian update_node + edge re-write for `parent_ids` changes |
+| `POST /new` (`handleNewSubmit`) | mBrian create_node + `child_of` edges |
+| `POST /i/{path}/reparent` (`handleReparent`) | edge delete + re-create for `child_of` |
+| `/admin/bulk` (`handleBulkApply`, `handleBulkChip`) | bulk mBrian updates; one mBrian write per row |
+| `/admin/classify` (`handleClassify`) | mBrian update + add `child_of` edge |
+| `POST /views/...` (5j editor) | unchanged if views stay in `projax.views`; rewired if they move (Q5) |
+| MCP `create_item` / `update_item` / `delete_item` | mBrian MCP create / update / soft_delete |
+| MCP `add_link` / `remove_link` | mBrian create_edge / delete_edge |
+
+### Validation (Phase 5c itemwrite package)
+
+The pre-flight validator stays as projax-handler logic — projax UI / MCP still surface friendly errors for `KindInvalidSlugFormat` / `KindSlugCollision` / `KindCycle` / etc. before round-tripping. The DB-level enforcement moves to mBrian's per-user unique index on slug (covers collision) + projax's `paths` recomputation (covers cycle detection). Trigger-level cycle detection on mBrian's edges is a mBrian-side ask (mb-G optional).
+
+### Cycle + slug-collision semantics
+
+Per §2.1: projax loses per-parent slug uniqueness; per-user uniqueness wins. The validator's KindSlugCollision rule needs updating to reject any duplicate slug across the whole projax-managed set, not just under the same parent.
+
+Cycle detection: projax today does it via the path trigger (cycle = self-ancestor). After migration, projax fetches all projax nodes + their child_of edges, walks the closure on every write, rejects cycles. Cheap at m's scale.
+
+---
+
+## §6 — Integrations (CalDAV / Gitea / mai.projects)
+
+### CalDAV + Gitea
+
+The link bundle (per §2.2) moves to mBrian edges with structured metadata. The CalDAV / Gitea **clients** + their caches stay projax-side (the aggregator owns these). The render path queries mBrian for "which items have caldav-list edges + what URLs," then fans out to the existing CalDAV client. Net effect: the fan-out stays where it is; only the source of "what to fan out for" changes.
+
+### mai.projects bidirectional sync (Phase 1.5)
+
+The Phase 1.5 trigger pair (mai.projects ↔ projax.items) is the most fragile piece of the integration today. After Phase 6:
+
+- (a) **Keep the trigger pair**, pointing the mai.projects view at the migrated mBrian nodes. Requires rewriting the trigger functions to read from mBrian; significant complexity because mai.projects expects projax.items columns.
+- (b) **Move the bridge to projax handler layer**: a sync worker watches mai.projects changes + writes mBrian; mBrian node changes flow back via a webhook or periodic poll. Slower but decoupled.
+- (c) **Drop the bridge entirely**: mai.projects becomes legacy; mai workers consume mBrian directly via MCP. Cleanest, but requires mai-side work to migrate workers/tasks/sessions FKs.
+
+**Inventor pick: (b)** — the bridge stays operational without bleeding mBrian schema details into mai.projects code, and m can sunset it gradually. (c) is the right long-term shape but it's another migration project; out of scope for Phase 6.
+
+This is **Q2** for m.
+
+---
+
+## §7 — Migration mechanics (mBrian-owned)
+
+Per m's Q7=(a) hard-cut + Q4=(a) "mbrian must own the migration": the one-shot script lives in `m/mBrian`. projax-side provides the input snapshot + the rules in this doc; mBrian-side owns the execution.
+
+### projax-side input snapshot
+
+A helper command in `cmd/projax-snapshot/main.go` produces a `projax_snapshot.json` containing every live `projax.items` row + every `projax.item_links` row, shaped for direct consumption by the mBrian-side script. One file, deterministic, round-trippable. Ships in slice 0 (the snapshot handoff, see §8).
+
+### mBrian-side script outline (for the m/mBrian issue body)
+
+1. Load `projax_snapshot.json`.
+2. Two-pass: pass 1 creates every node; pass 2 writes every edge (parent edges + item_links → projax-* edges).
+3. For each item:
+   a. New mBrian uuid OR preserve the projax uuid (mBrian-side picks; either works given m's Q11 audit metadata is the durable reference).
+   b. INSERT into `mbrian.nodes` with `type=['project']` (or `['project']` + co-type per `kind`), `title`, `slug`, `aliases`, `metadata={projax: {...}, projax_origin: <old_id>}`.
+   c. Where projax had multiple paths (same node under multiple parents), DEDUPE by slug — one node, multiple `child_of` edges.
+4. For each parent edge: INSERT `mbrian.edges (source=new_id, target=parent_new_id, rel='child_of')`.
+5. For each item_links row: INSERT `mbrian.edges` with `rel='projax-<ref_type>'` and `metadata` carrying the structured payload per §2.2.
+6. For projax.views (5j): NOT migrated — per m's Q5=(a), the views table stays projax-resident.
+7. Smoke check: count(mbrian.nodes WHERE metadata->>'projax_origin' is not null) == count(items in snapshot).
+8. Hand off to projax with the new uuid map (`{old_uuid: new_uuid}`) so projax-side caches can warm.
+
+### Idempotency
+
+Pre-flight: the script checks `metadata.projax_origin` and skips already-migrated origins on re-run. m can re-run safely if the script aborts mid-way.
+
+### Lossy bits (acceptable per m's stance)
+
+- `paths text[]` array is not preserved — projax-side adapter recomputes from edges per §4.
+- mai.projects mirror rows: per Q2=(b), a handler-layer bridge worker re-syncs after migration; the Phase 1.5 trigger pair stays disabled.
+
+### Blast-radius containment
+
+mBrian-side runs the script with triggers paused, smoke-checks the count + spot-checks the 5 representative items in projax's checklist, then commits + signals projax-side to start slice C (read-path).
+
+---
+
+## §8 — Implementation slicing (re-baselined)
+
+Six slices. The big shift from the original draft: the mBrian-side ask compresses to one [schema] convention node + one migration script (both mBrian-owned per m's Q4). Slice 0 is a small projax-side helper that ships the snapshot. The hard gate is the migration landing — projax-side B reads it as the trigger to start.
+
+- **0. projax-side snapshot helper** — `cmd/projax-snapshot/main.go`. Dumps live `projax.items` + `projax.item_links` to `projax_snapshot.json`. Ships first; minimal risk; deliverable mBrian needs.
+
+- **A. mBrian-side: [schema] convention node + data-migration script** — m/mBrian owns. The [schema] node lives under a new `[topic]` hub `projax-integration`. The script consumes the snapshot from slice 0 and writes 47ish nodes + their edges per §7. mBrian-side post-flight: smoke-check count + spot-check 5 items per the projax checklist.
+
+- **B. projax-side read-path adapter** — projax-side. `store/` package rewired against mBrian's MCP / SQL surface. The `Item` struct stays; method bodies rewrite. All UI + aggregator tests stay green (they only see Item shape). Per-request snapshot cache to avoid N+1 calls. Reads-only soak before slice C.
+
+- **C. projax-side write-path** — projax-side. Every handler + MCP write rewires through the adapter to mBrian. itemwrite validator updates for the per-user slug rule (Q6). Cycle detection on the in-memory closure (Q9).
+
+- **D. mai.projects bridge worker** — projax-side (Q2=(b)). Disable the Phase 1.5 trigger pair; ship a small worker that observes mai.projects writes + reflects them into mBrian, and vice versa. Decoupled, killable.
+
+- **E. Drop `projax.items` + `projax.item_links`** — projax-side. Migration `0018_drop_projax_items.sql`. Triggers off after one shift's stable read+write soak on mBrian. `projax.views` stays (Q5).
+
+Dependency graph:
+
+```
+0 (projax snapshot) ──→ A (mBrian [schema] node + migration script run)
+                               │
+                               ▼
+                      B (projax read-path) ──→ C (projax write-path)
+                                                        │
+                                                        ├──→ D (mai bridge worker)
+                                                        ▼
+                                                E (drop projax tables)
+```
+
+Slice 0 unblocks A. A is mBrian-owned and the hard gate for everything else. B → C can ship together if green; otherwise B-first soak.
+
+CalDAV / Gitea integrations stay where they are (Q3=(a)) — no slice F needed in the original sense.
+
+---
+
+## §9 — Cross-repo coordination (settled)
+
+Per m's Q4=(a) + his words *"mbrian must own the migration"*:
+
+1. **Protocol**: file a Gitea issue on `m/mBrian` with "blocks projax phase 6" tag. Routed via otto/head per global Channel Routing. Head files it; kahn drafts the body.
+
+2. **Ownership split**:
+   - mBrian-side owns: the `[schema]` convention node (MB-B) + the one-shot data-migration script.
+   - projax-side owns: the snapshot helper (slice 0), the read-path adapter (slice B), the write-path (slice C), the mai bridge (slice D), the table drop (slice E).
+
+3. **Sequencing**: slice 0 produces the snapshot → mBrian-side A consumes it + runs the migration → mBrian-side signals back → projax-side starts B. The Gitea issue is the durable trace; the delegation reply chain is the real-time signal.
+
+4. **Design-doc sharing**: this plan stays in `m/projax`. The m/mBrian issue body (drafted alongside this re-baseline, delivered to head) excerpts §2 (schema mapping), §3 (the one [schema] node ask), §7 (the script outline), and the spot-check checklist.
+
+---
+
+## §10 — Open questions (all answered 2026-05-29)
+
+All 11 questions resolved. m confirmed every inventor pick. Section retained as the historical record + so a future hand can audit the decision rationale.
+
+
+
+The 8 from issue #5 plus what surfaced during this survey.
+
+**Q1 — mBrian node type for projax items**
+- (a) Reuse existing `'project'` type, add `'area'` if missing, multi-typed for both. — **inventor pick** (existing type minimises mBrian-side churn).
+- (b) New dedicated `'projax-item'` / `'work-item'` type.
+
+**Q2 — mai.projects bidirectional sync disposition** (§6)
+- (a) Keep the trigger pair (rewrite to read from mBrian).
+- (b) Move to projax handler-layer bridge worker. — **inventor pick** (clean decoupling).
+- (c) Drop entirely; migrate mai-side FKs.
+
+**Q3 — CalDAV + Gitea integration ownership** (§6)
+- (a) Clients + caches stay projax-side; only the "which items have these links" lookup moves to mBrian. — **inventor pick** (minimal change to aggregator).
+- (b) Migrate CalDAV/Gitea ownership to mBrian edges + projax becomes a pure renderer.
+
+**Q4 — mBrian head contact protocol** (§9)
+- (a) Through otto/head per Channel Routing (default per global rule). — **inventor pick**.
+- (b) Direct to a future mBrian/head worker.
+- (c) m himself owns mBrian schema work — file Gitea issue on m/mBrian.
+
+**Q5 — projax.views (5j) disposition**
+- (a) Keep as projax-resident table — views are projax-UI state, not graph data. — **inventor pick**.
+- (b) Migrate to mBrian nodes with type=`[view]`; one node per saved view.
+- (c) Drop the table; user views become a derived shape from mBrian metadata on the items themselves.
+
+**Q6 — Slug uniqueness model**
+- (a) Adopt mBrian's per-user unique (loses "two paliads under different roots" case). — **inventor pick** (simpler; m hasn't used the per-parent split in practice).
+- (b) Keep projax's per-parent rule via projax-handler validator + mBrian per-user check disabled for projax nodes (requires mBrian-side scoped-uniqueness work).
+
+**Q7 — Migration mechanics** (§7)
+- (a) Hard-cut, one script, accept data loss. — **inventor pick** (matches m's stance).
+- (b) Phased dual-write + soak.
+
+**Q8 — Tags model**
+- (a) Keep tags in `metadata.projax.tags` (projax sees them as before; mBrian doesn't index them). — **inventor pick** for v1.
+- (b) Lift each tag to a `[tag]` node + `tagged` edges (mBrian convention).
+- (c) Hybrid — keep metadata for projax compatibility AND wire tagged-edges for mBrian visibility.
+
+Q8(c) is the "right" long-term shape but doubles the write surface in slice D. Recommend deferring to a Phase 7 polish.
+
+**Q9 — Cycle detection placement**
+- (a) projax-handler-side via in-memory closure walk before write. — **inventor pick** (cheap at m's scale).
+- (b) mBrian-side via trigger on `edges` (mb-G ask).
+
+**Q10 — Projax MCP surface**
+- (a) Keep projax MCP tools (`mcp__projax__*`); they now route through the adapter. — **inventor pick** (no MCP client change).
+- (b) Sunset projax MCP; users call mBrian MCP directly.
+
+**Q11 — `projax_origin` audit metadata** (§7)
+Per the migration script, every migrated node carries `metadata.projax_origin = <old uuid>`. Keep indefinitely (audit trail), purge after one shift (cleanup), or never write it (trust). **Inventor pick**: keep indefinitely.
+
+---
+
+## §11 — Risk register
+
+| risk | likelihood | mitigation |
+|---|---|---|
+| mBrian-side schema work (slice A) blocks projax indefinitely | medium | clear delegation + Gitea issue with "blocks projax phase 6" tag; m can dispatch fast-track |
+| 47-item migration script silently drops fields | low | smoke check (item count parity) + spot-check 5 items post-migration before slice C |
+| Slug collision on multi-rooted items (e.g. two `paliad`s) | medium | pre-migration script: detect collisions, dedupe to one node with multiple `child_of` edges, log skips |
+| mai.projects trigger pair breaks mid-migration | medium | turn off the triggers before migration, rebuild post-migration (Q2 (b) bridge takes over) |
+| Adapter introduces N+1 mBrian calls during render | medium | one ListAll + one LinksByRef query per request, cached per-request; profile after slice C |
+| Phase 5j views surface breaks | low | views stay projax-resident per inventor pick on Q5; no migration cost |
+| flexsiebels.de public-listing renderer breaks | medium | metadata.projax.public.* bundle preserves the shape; spot-test before slice E |
+| Cross-repo coordination delay | medium | filed as Gitea issue (durable) + delegation (real-time signal); both paths active |
+
+---
+
+## §12 — Test plan headlines
+
+### Slice B (migration script)
+- `TestMigrateScriptSmokes` — 5 hand-crafted projax.items + 3 item_links → mBrian nodes + edges; count parity assertion.
+- `TestMigrateScriptIdempotent` — second run = no new nodes.
+- `TestMigrateScriptSlugCollision` — two multi-rooted items same slug → one node with two `child_of` edges, log entry.
+
+### Slice C (read-path)
+- `TestAdapterListAllReturnsItemsFromMBrian` — seed mBrian nodes with `projax_origin`, ListAll returns matching Items.
+- `TestAdapterGetByPathResolvesEdges` — `dev.paliad` walks `child_of` edges to leaf node.
+- `TestAdapterPathsArrayMultiRoot` — node with two `child_of` edges produces 2 entries in `it.Paths`.
+
+### Slice D (write-path)
+- `TestHandleDetailWriteUpdatesMBrian` — POST /i/dev.paliad updates the mBrian node's title.
+- `TestHandleReparentRewritesChildOf` — POST /i/dev.paliad/reparent deletes old edge + creates new one.
+- `TestSlugCollisionRejected` — second create with same slug rejected with KindSlugCollision.
+
+### Slice E (drop)
+- migration `0018_drop_projax_items.sql` smoke test: `\dt projax.*` returns only `projax.views` + `projax.schema_migrations`.
+
+### Slice F (integrations)
+- per Q2 answer — bridge-worker test (Option b) OR mai-FK migration test (Option c).
+
+---
+
+## §13 — References
+
+- `~/dev/mBrian/db/001_initial_schema.sql` — mBrian schema baseline.
+- `~/dev/mBrian/docs/schema.md` — schema doc.
+- `~/dev/mBrian/CLAUDE.md` — mBrian conventions + relation to flexsiebels.
+- `projax/store/store.go` — current Item struct + projax store API.
+- `projax/store/views.go` — Phase 5j views table.
+- `projax/docs/design.md` — current PRD.
+- `projax/docs/plans/views-redesign.md` — Phase 5j design.
+- `m/projax` issue #5 — m's Option A pick.
+
+---
+
+## §14 — Status
+
+- **Phase A (this doc)**: drafted by kahn 2026-05-29, re-baselined same day against live mBrian schema after m's 11 answers landed. All §10 questions resolved.
+- **m/mBrian Gitea issue**: body drafted; head files it under "blocks projax phase 6" tag.
+- **Phase B (projax-side coder)**: blocked on (1) slice 0 snapshot helper ships + (2) mBrian-side migration runs + signals back. NO coder flip yet.
+- **Slice 0 (projax-side snapshot helper)**: scoped, not yet built. Smallest first-step on projax-side; ready when head greenlights.
+- **No code changes** in this branch beyond this doc.