# RFC 001 — Global palace with local fallback (`mempalace-edge`)

| | |
| --- | --- |
| **Status** | Draft — design agreed, not implemented |
| **Created** | 2026-08-08 |
| **Applies to** | mempalace 3.6.0, mempalace-toolkit @ `96699f2`, pi-devbox ≥ v1.3.0 |
| **Decision** | Phases 0–2 + 4 in scope. **Phase 3 (full pull replication) explicitly deferred** — "a laptop that can reach its own stuff plus whatever it can reach" is good enough. **Centralization is strictly opt-in — solitary devbox operation remains the default and must not change (§1.1).** |

**Read this first if you are asked to "centralize MemPalace" / "sync palaces between machines".** Most of the
hard-won facts below are non-obvious and two of them are actively destructive if you guess wrong
(§7.1, §7.2). The evidence index in §10 lets you re-verify any claim without re-reading 45k lines.

---

## 1. The problem

One palace per machine per harness. Today: a pi-devbox container on `EMB-7KJ4VR4G`, another on
`tor-ms22`, opencode-devbox containers, `MBP-M1-2020`, plus native hosts — each with a private
`~/.mempalace`. Consequences:

1. **Memory is sharded by accident of where you happened to be working.** A decision recorded on the
   laptop is invisible to the agent on the desktop.
2. **Container recreates are amnesia events** unless the palace happens to be host-bind-mounted.
3. **The KG is the worst hit** — `kg_query`/`kg_timeline` answers depend on which machine you ask.

**Target state:** one primary palace holds the fleet's memory. Every client keeps working when the
primary is unreachable (writes buffer locally, reads degrade to local), and reconciles when it
returns. Access is authenticated per device, with a sane authorization policy.

### 1.1 Hard requirement: solitary-first, centralization strictly opt-in

**This is a requirement, not a preference, and it constrains every choice below.**

Centralization solves a problem specific to *this* usage pattern: several machines and containers
(pi-devbox, opencode-devbox, native hosts) doing development and other work against a **common set of
artifacts**. For most users of the published `joakimp/pi-devbox` and `joakimp/opencode-devbox` images
it is **useless** — one machine, one palace, done. Evidence that this is already the norm: all three
sampled `opencode-devbox` deployments (`docker-compose-repo/{synlig,nyvaken,devbox-affection}/`)
contain **zero** mempalace references.

| ID | Requirement |
| --- | --- |
| **R1** | **Solitary operation stays the default and stays unchanged.** With no `MEMPALACE_*` variables set, a devbox must behave exactly as it does today: harness → local `mempalace-mcp` over stdio, palace at `~/.mempalace`. No extra process, no outbox, no network calls, no new failure mode, no measurable startup cost. |
| **R2** | **Opt-in lives in `docker-compose.yml` + `.env`** — the mechanism users already know. No opt-in via image rebuild, no baked-in defaults, no `latest-central` variant. |
| **R3** | **Credentials only in `.env`** (`chmod 600`, gitignored). Never in `docker-compose.yml`, never in the image, never on a command line (visible in `ps`), never logged. Compose passes them through with a `${VAR:-}` empty default so solitary users never define them. |
| **R4** | **No new required services.** The primary stays in the separate standalone `docker-compose.mempalace.yml` project; it is never merged into the main compose file. A solitary `docker compose up` starts exactly what it starts today. |
| **R5** | **Degrade, never fail, when mempalace is absent.** opencode-devbox may not ship mempalace at all, so any wiring must be additive and skipped when the binary is missing — the probe-and-warn idiom `install.sh` already uses (`warn` + `return 0`, never halt). |
| **R6** | **Reversible.** Commenting the `.env` lines out returns the container to pure solitary operation, with the local palace intact and readable. |

**Acceptance test for R1** (must pass before Phase 2 ships): bring up a devbox with no `MEMPALACE_*`
variables; assert the palace tool list, drawer counts and diary writes are identical to the previous
image, and that no edge/outbox process exists (`pgrep -f mempalace-edge` → empty).

### 1.2 The opt-in surface

The existing convention is already the right one — **extend it, do not invent a new one.** pi-devbox's
`.env.example` lines 12–23 already ship a commented `MEMPALACE_REMOTE_URL` / `MEMPALACE_REMOTE_TOKEN`
pair under the heading "MemPalace memory (local by default)", and `docker-compose.yml:79-83` already
ships the `devbox-palace` volume commented out. So the opt-in ladder becomes three states derived
from two variables — **both existing behaviours are preserved, the third is new**:

| `MEMPALACE_REMOTE_URL` | `MEMPALACE_EDGE` | Behaviour | Status |
| --- | --- | --- | --- |
| unset | — | local stdio `mempalace-mcp`, palace at `~/.mempalace` | **default, today, unchanged (R1)** |
| set | unset/`0` | direct remote HTTP; no local palace, no offline | today (`96699f2`), unchanged |
| set | `1` | `mempalace-edge`: local-first writes + outbox → primary + merged reads | **new (Phase 2)** |

> **Volume coupling reverses under edge mode — document it prominently.** Today `.env.example` correctly
> says that with `MEMPALACE_REMOTE_URL` set "*the devbox-palace volume is then irrelevant*", because the
> remote owns all state. Under **edge** mode that flips: the local palace holds the outbox and all
> local-first writes, so an un-persisted palace means **losing un-flushed writes on container
> recreate**. Opting into `MEMPALACE_EDGE=1` therefore *requires* uncommenting
> `devbox-palace:/home/developer/.mempalace`.

Corollary for §4.1: **`mempalace-edge` must not be in the path unless opted in.** Registering it
unconditionally (letting it decide by env at runtime) is tempting — one static config for every
harness — but it violates R1 by inserting a process and a failure mode into every solitary user's
setup. Selection must happen at registration time. See open question §9.6.

---

## 2. Verified starting point (as of 2026-08-08)

Two of the three pieces already exist. This is not greenfield.

| Piece | State | Evidence |
| --- | --- | --- |
| **Primary server** | ✅ **Exists.** `mempalace serve --host --port --token --tls-cert --tls-key --read-only --allow-insecure`. Bearer token compared with `hmac.compare_digest`, **mandatory** on non-loopback binds (unless `--allow-insecure`), TLS 1.2+ resolved *before* bind, Host-header pinning + `Origin` allowlist (anti-DNS-rebinding), 16 MiB body cap, token-free `/healthz`. | `cli.py:cmd_serve` (~1448); `mcp_server.py:5205-5215`, `5284-5289` |
| **Remote client** | ⚠️ **Exists for pi only, and it is either/or.** `createClient()` picks stdio *or* HTTP once at process start. | `extensions/pi/mempalace.ts:629-641` |
| **Fallback + resync** | ❌ **Absent everywhere.** On remote failure the pi bridge re-handshakes the same URL, then **de-registers all palace tools** and runs blind. | `extensions/pi/mempalace.ts:665-673` |
| **opencode client** | ❌ **stdio only.** `{"type":"local","command":["mempalace-mcp"]}` in `~/.config/opencode/opencode.json`. No remote entry exists anywhere in `myconfigs`. | `myconfigs/tor-ms22.home.arpa/.config/opencode/opencode.json` |
| **Server compose** | ✅ Exists: `pi-devbox/docker-compose.mempalace.yml` (canonical) + a tor-ms22 derivative (`docker-compose-repo/tor-ms22/pi-devbox/`, `df2c2ae`, port 8766, uid 1000, binds the real `~/.mempalace`). Not enabled. | pi-devbox CHANGELOG v1.3.0 (2026-07-02) |

> **Stale docs warning.** `docker-compose.mempalace.yml`, `.env.example` and CHANGELOG v1.3.0 all say the
> HTTP transport is unauthenticated and should be fronted by a reverse proxy. That was true for
> `mempalace-mcp --transport http` in the v1.3.0 era. **mempalace 3.6.0's `serve` has token + TLS
> built in** (upstream #1877). Fix those comments during Phase 1. Specifically:
> `pi-devbox/.env.example:21` still advertises `mempalace-mcp --transport http --host 0.0.0.0 --port
> 8765` as the way to serve a shared palace — replace with `mempalace serve --token … --tls-cert …`,
> and change the example URL from `http://mempalace.lan:8765/mcp` to `https://`.

### Two things that sound like the feature and are not

- **`sync.py` is not replication.** It is gitignore-aware drawer *deletion*: "*Removes drawers whose
  source files are now gitignored, deleted, or moved out of the project*" (`sync.py:1-12`). See §7.2 —
  running it against a shared palace is a fleet-wide memory wipe.
- **`wal/write_log.jsonl` is not a replayable WAL.** `_WAL_REDACT_KEYS` strips
  `content`/`content_preview`/`document`/`entry`/`entry_preview`/`query`/`text` and replaces them with
  `"[REDACTED N chars]"`; all 12 references are writers, there is **no reader** and no `replay`
  function (`wal.py:74`). Reconstructing memory from it is information-theoretically impossible.

---

## 3. Why we sync operations, not databases

Row-level / file-level replication of a palace is a trap in this codebase. Four findings, each
independently disqualifying:

1. **Vectors are not portable.** Embeddings are computed **client-side** — `backends/pgvector.py:6-8`:
   "*Embeddings are still produced locally by MemPalace through the core embedding wrapper before
   vectors are written to Postgres.*" Cross-architecture ONNX determinism (arm64 macOS vs x86-64
   Linux, different execution providers) is not guaranteed. → **Ship text + metadata, always re-embed
   on receipt.** Cheap and safe: the raw text is always stored as the chroma document.
2. **KG rows cannot be copied.** `triples` has **no** `UNIQUE(subject,predicate,object,valid_from)` —
   only `id` is unique, and `make_triple_id` embeds `datetime.now()`. A row copy therefore duplicates
   every fact. But `add_triple()` guards at the application level (`SELECT id … WHERE subject=? AND
   predicate=? AND object=? AND valid_to IS NULL` → returns the existing id), so **replaying `kg_add`
   is idempotent for open facts** (`knowledge_graph.py:163-178`, `305-313`).
3. **Only one write path has deterministic IDs.**

   | Write path | ID recipe | Same content on 2 hosts → same ID? |
   | --- | --- | --- |
   | `add_drawer` / `checkpoint` | `drawer_{wing}_{room}_{sha256(wing\|room\|content)[:24]}` | **YES** — content-addressed, merges for free |
   | project/format miner | `…sha256(source_file\|chunk_index)` | **NO** — absolute path (`/Users/joakim/x` vs `/workspace/x`) |
   | convo miner | `…sha256(source_file\|extract_mode\|chunk_index)` | **NO** — same reason |
   | diary | `diary_{wing}_{YYYYmmdd_HHMMSSffffff}_{sha256(entry)[:12]}` | **NO** (µs timestamp) — but the 12-hex suffix is a usable content dedup key |
   | KG triple | `t_{s}_{p}_{o}_{sha256(valid_from\|recorded_at)[:12]}` | **NO** (`recorded_at = now()`) |

   (`ids.py:56,71` — `ID_RECIPE = "v3"`, length-prefixed delimited hashing.)
4. **Batch dedup will not save a naive merge.** `dedup.py` groups by `source_file` and only compares
   *within* a group (cosine < 0.15) → cross-host duplicates with differing paths are never compared.
   The mechanism that *does* work is write-time: `tool_check_duplicate(content, threshold=0.9)` queries
   the whole collection, and `mempalace_checkpoint` already runs it per item.

**Conclusion:** the MCP tool surface is already a small, coarse-grained, mostly-idempotent operation
vocabulary. Log the *intent*, replay the *intent*. That sidesteps chroma internals, chunking,
embedder drift and vector portability in one move.

---

## 4. Design: `mempalace-edge`, a local MCP proxy

### 4.1 Shape

Do **not** put fallback logic in `extensions/pi/mempalace.ts` — opencode would need it again, and it
may not support remote MCP at all (§9.1). Instead: a sidecar that *is* an MCP server.

```
pi        (mempalace.ts, stdio) ─┐
opencode  (mcp: type=local)     ─┼──►  mempalace-edge  ──HTTPS MCP──►   PRIMARY
mempalace CLI (local palace)    ─┘        │   (stdio MCP server)       mempalace serve
                                          ├─ child: mempalace-mcp       --token --tls-cert
                                          │  (local palace, always writable)
                                          └─ outbox.sqlite (durable op queue)
```

**`mempalace-edge` needs zero mempalace internals** — it is an MCP-to-MCP proxy. It speaks stdio down
to a child `mempalace-mcp` and HTTPS up to the primary, reusing the `RemoteMcpClient` already written
in `96699f2` (`extensions/pi/mempalace.ts:390`, vendored from `pi-extensions/mcp-loader.ts` — mind the
`MCP-STREAMABLE-HTTP-CLIENT-SYNC: v1` drift token if you copy it again).

Why this shape wins:

- **One implementation for every harness.** opencode's change is one line:
  `"command": ["mempalace-edge"]`. pi's is one line. The CLI is untouched.
- **Tools never vanish** from the tool list, so wake-up context injection keeps working offline —
  unlike today's fail-soft de-registration.
- **Survives mempalace upgrades**: coupled to the tool schema, not to chroma/HNSW.
- The remote transport is **sessionless JSON-RPC** today (per `96699f2`'s own note), so reconnect
  after an outage is cheap — there is no session to re-establish.

**But per R1, that one-line change is conditional, not baked in.** The edge binary is present in the
image (it costs nothing unused) and inserted into the path only when `MEMPALACE_EDGE=1`:

- **pi**: `createClient()` (`extensions/pi/mempalace.ts:629`) already branches on env at startup — add a
  third branch. Zero change to the default path.
- **opencode**: the MCP server entry is static JSON, so the entrypoint must template it — write
  `command: ["mempalace-edge"]` only when opted in, otherwise leave today's
  `["mempalace-mcp"]` untouched. If mempalace is absent entirely (as in all three sampled
  opencode-devbox deployments), write nothing and warn (R5).

### 4.2 Routing policy

`service.py:29,54,72` already ships the exact three-way split we need — `READ_TOOLS`,
`WRITE_TOOLS`, `MAINTENANCE_TOOLS` (`{mine, sync, reconnect}`) — plus `classify_tool()`.

| Class | Primary up | Primary down |
| --- | --- | --- |
| **read** (`search`, `kg_query`, `diary_read`, `list_*`, `traverse`…) | query **both**, merge ranked lists, dedupe by drawer id | local only, response flagged `degraded: true` |
| **write** (`add_drawer`, `checkpoint`, `diary_write`, `kg_add`…) | apply local **and** enqueue → primary | apply local, enqueue, keep working |
| **maintenance** (`mine`, `sync`, `reconnect`) | **never proxied** — local only (§5, §7.2) | local only |
| **destructive** (`delete_drawer`, `delete_by_source`, `delete_tunnel`…) | admin-scoped only; tombstone, never hard-delete remotely | local only |

> ⚠️ **`classify_tool()` must be treated as fail-closed.** `mempalace_kg_supersede` is a real MCP tool
> (3 references in `mcp_server.py`) but is **absent from `WRITE_TOOLS`** → `classify_tool()` returns
> `"unknown"` for it. An edge proxy that routed "unknown" as read would silently drop supersede
> operations. Maintain our own tool→class table, default unknown ⇒ **write**, and file the upstream fix.

**The merged-read trick is what makes Phase 3 optional.** Both palaces return ranked results with
distances; if the embedder identity matches (§7.4) the distances are comparable, so a union +
re-sort + dedupe-by-id gives a correct combined result set. You get fleet-wide recall *without*
replicating anything. Offline you simply see less.

KG reads are the exception: unioning triples is unsafe because `invalidate`/`supersede` are
order-dependent. Use **primary-first, local-fallback** (no union) for `kg_*` reads, and accept that an
offline KG answer is incomplete.

### 4.3 Outbox

Model it on `daemon.py`, which already implements a durable local job queue and is the closest
existing prior art (token auth via `ensure_token`, 0600, per-palace state dir, `MAX_ATTEMPTS = 3`,
`recover_running`, `JOB_RETENTION_DAYS = 7`). Its key primitive is worth copying verbatim:

```sql
CREATE UNIQUE INDEX IF NOT EXISTS idx_jobs_dedupe_active
  ON jobs(dedupe_key) WHERE state IN ('queued', 'running');
```

A TOCTOU-safe, cross-process "at most one active job per key". Our outbox rows:

| Column | Purpose |
| --- | --- |
| `op_id` | `sha256(origin_device, local_seq, tool_name, canonical_payload)` — stable across retries, the primary's idempotency key |
| `local_seq` | Per-device monotonic counter → **causal order** for `kg_invalidate`/`supersede` replay |
| `origin_device`, `origin_host` | Provenance (§7.3) |
| `tool_name`, `payload_json` | The MCP call to replay |
| `state`, `attempts`, `created_at`, `flushed_at`, `error_json` | Retry/audit |

Flush = drain in `local_seq` order, stop on first hard failure (preserve ordering), exponential
backoff, resume on reconnect. The primary de-dupes on `op_id`; `add_drawer`'s own pre-write probe and
`add_triple`'s open-fact guard make replay safe even if `op_id` tracking is lost.

`write_routing.py` is the upstream-shaped seam for this if we ever want it in core: its
`WriteRoutingPolicy{DIRECT,PREFER,REQUIRE}` → `WriteRoutingTarget{DIRECT,DAEMON,BLOCKED}` enums would
gain a `REMOTE` target. The module says it "*changes no caller defaults by itself*" — i.e. it exists
precisely to be extended.

---

## 5. Not everything should be global

Per-wing replication policy, declared in edge config:

| Policy | Wings | Rationale |
| --- | --- | --- |
| `replicated` | diaries, `wing_pi`, checkpoints, KG, hand-authored notes | Small, curated, content-addressed → **already merge-safe** |
| `local` | mined code/docs (e.g. the 13,597-drawer `workspace` wing on this host) | Derived data, re-mineable from git, and carries exactly the path-dependent IDs that break merging (§3.3) |

This shrinks the hard problem to the layer that is already safe, and it is why **`mine` must never be
remote**: the primary serializes *every* request behind one lock (§7.5), so a bulk remote mine would
stall every other agent in the fleet.

---

## 6. Security model

The transport is largely solved; **the gap is authorization, not cryptography.**

### 6.1 Threats, in priority order

1. **Memory poisoning / persistent cross-machine prompt injection — the underrated one.** Palace
   content is injected into agent context at wake-up. A shared palace means one careless or
   compromised container can plant instructions that *every other agent in the fleet reads as trusted
   memory*. Mitigation: provenance on every record (§7.3), don't auto-inject wake-up content authored
   by devices outside a trusted set, keep an admin-only wing for anything instruction-shaped.
2. **Aggregation raises exfiltration impact.** One primary holds every machine's diaries — which
   already quote internal hostnames, paths and token prefixes. Mitigation: per-wing ACL; don't put
   secrets in memory (the WAL redaction list exists for a reason); private-network-only exposure.
3. **Accidental mass deletion** by a client (`sync`, `delete_by_source`) — see §7.2.
4. **Availability**: the server is single-writer by design; one long operation blocks everyone.

### 6.2 Policy

| Control | Decision |
| --- | --- |
| **Network posture** | Primary **never** internet-exposed. Bind loopback in the container; publish only onto the private overlay / existing tunnel (Pangolin/newt). |
| **Transport** | TLS via `serve --tls-cert/--tls-key`, or terminate TLS **+ mTLS** in the reverse proxy (cheaper than patching Python's TLS surface). |
| **Authentication** | **Per-device bearer tokens**, not the one shared token. Server-side registry `token → {device_id, scopes}`. Store in the existing `.env.age` flow, 0600 on disk. Enables revoking one laptop and rotating without a fleet outage. |
| **Authorization** | Per-device read/write **wing globs**. Server-side refusal of `mine`/`sync`/`delete_*` except for an admin device. `--read-only` gives a free observer tier. |
| **Provenance/audit** | `origin_host` + `origin_device` + `op_id` on every record (§7.3); server-side append-only op log. |
| **Recovery** | Deletes as tombstones; server-side backups with `backups.py` retention (`MEMPALACE_MAX_BACKUPS`). |
| **DoS** | Keep the 16 MiB cap; add rate limiting; no remote `mine`. |

---

## 7. Landmines — Phase 0 runbook

Do these **before** any cutover. 7.1 and 7.2 cause silent data loss.

### 7.1 `MEMPALACE_PALACE_PATH` ≠ `--palace` (silent empty KG)

```python
# mcp_server.py:708-711  (_palace_flag_given = bool(_args.palace), line 325)
def _resolve_kg_path() -> str:
    if _palace_flag_given:
        return os.path.join(_config.palace_path, "knowledge_graph.sqlite3")
    return DEFAULT_KG_PATH        # knowledge_graph.py:49 → ~/.mempalace/knowledge_graph.sqlite3
```

`cmd_serve` **always** passes `--palace`. So the moment you start the server, the KG becomes
`<palace>/knowledge_graph.sqlite3` — a *different file* from the live `~/.mempalace/knowledge_graph.sqlite3`.
The vector store looks fine and the knowledge graph is silently empty.

Four stores, **three** location rules:

| Store | Location rule |
| --- | --- |
| drawers | backend-abstracted (`BaseCollection`) |
| `knowledge_graph.sqlite3` | HOME-anchored **unless `--palace` flag** (`knowledge_graph.py:49`) |
| `hallways.json` | derived from `palace_path`, with legacy HOME fallback (`hallways.py:73,83`) |
| `known_entities.json` | HOME-anchored (`miner.py:701`) |

**Action:** `mv` all three files into the palace directory before first `serve`, and verify
`kg_stats` is non-empty afterwards. Corollary: **a shared pgvector/qdrant backend shares drawers and
nothing else** — it would leave the KG as fragmented as it is today. That is why the shared-backend
option is *not* the answer.

### 7.2 Never run `mempalace sync` against a shared palace

It classifies drawers whose source files are absent **on the running host** as orphans and deletes
them; `_auto_detect_project_roots` guesses roots from drawer metadata, so the blast radius is
data-dependent rather than obvious. From a laptop that lacks the repos, it is a fleet-wide wipe.
**Action:** edge blocks `mempalace_sync` from ever reaching the primary; document it; consider an
upstream `--refuse-shared` guard.

### 7.3 Add provenance metadata now

Today every drawer carries exactly `{wing, room, source_file, added_by, filed_at, id_recipe}`
(+`chunk_index`, `parent_drawer_id`); diaries add `{hall, topic, type, agent, date}`. `added_by`/`agent`
is the *agent* name (`pi`, `mcp`, `checkpoint`) — **never the machine**. So after any merge you cannot
tell which host wrote a record, cannot audit, and cannot compute per-device high-water marks.
Metadata is free-form, so this is cheap — but it is **impossible to backfill**. Do it first.

### 7.4 Embedder identity is client-local and currently toothless

`check_embedder_identity()` raises `DimensionMismatchError` / `EmbedderIdentityMismatchError`, but the
sidecar on this host reads `{"mempalace_drawers": {"model_name": "minilm", "dimension": 0}}` — and
`dimension: 0` means *unknown* and is **skipped**, so only the model *name* is compared. The sidecar
lives in the client's palace dir (`_sidecar.py`), so with a remote backend the check is per-client and
never centrally enforced. **Action:** the primary must reject writes from a client whose embedder
identity does not match, and merged reads (§4.2) must be disabled on mismatch — comparing distances
across models silently degrades recall.

### 7.5 Concurrency expectations

- `_HTTP_REQUEST_LOCK = threading.Lock()` wraps **every** dispatch (`mcp_server.py:5115`, held at
  `5346`/`5513`), commented: "*HTTP gives us a safer transport, not concurrent Chroma/HNSW mutation.*"
  The primary is a **single-writer, one-request-at-a-time** service. Size for a handful of agents.
- `mine_palace_lock` uses `fcntl.flock(LOCK_EX|LOCK_NB)` and exists because parallel HNSW inserts
  "*can corrupt the HNSW graph*" — but the lock **file** is HOME-derived (`~/.mempalace/locks/
  mine_palace_{sha256(realpath(palace))[:16]}.lock`) while the key is palace-derived. Two containers
  with different `~/.mempalace` mounts but the same palace path compute the same key on *different
  files* → **no mutual exclusion**.
- **Therefore: reject "put the palace on a NAS/SMB share and point everyone at it."** flock over
  NFS/SMB is unreliable, and the lock wouldn't be shared anyway. One process owning the files and
  serving HTTP is the supported model — which is exactly why `serve` exists.

---

## 8. Phasing

| Phase | Effort | Deliverable |
| --- | --- | --- |
| **0 — hygiene** | hours | §7 runbook: move KG/hallways/entities, add provenance metadata, ban `sync` on shared palaces, per-device tokens, fix stale "unauthenticated" docs (incl. `pi-devbox/.env.example:21`) |
| **1 — primary up** | hours, **no code** | `mempalace serve --token --tls-cert` on a private-net host (reuse `docker-compose.mempalace.yml` — keep it a **separate standalone project**, R4 — and mind port 8765 vs pi-studio; tor-ms22 already moved to 8766). Repoint pi clients via `MEMPALACE_REMOTE_URL`/`MEMPALACE_REMOTE_TOKEN`. **Shared memory today, no offline.** |
| **2 — `mempalace-edge`** | ~1 week | The actual ask: local-first writes + outbox flush + merged reads + per-wing policy. Fixes opencode as a side effect. **Ships with the §1.2 opt-in wiring (compose + `.env.example` + entrypoint templating) and must pass the R1 acceptance test.** |
| **3 — pull replication** | ~1 week | **DEFERRED (2026-08-08).** Server-side op-log with monotonic seq → each edge a full offline replica. Only needed if a laptop must hold *everything* offline. Accepted trade-off: offline recall = own writes + last-reachable state. |
| **4 — authz** | days | Per-wing ACL, per-device scopes, audit log, token rotation |

Phase 1 is worth doing on its own — it is pure configuration and immediately ends KG fragmentation
for online clients.

---

## 9. Open questions

1. **Does opencode's MCP config support a remote/HTTP transport at all?** Every sampled entry in
   `myconfigs` is `"type":"local"`; no documentation found either way. **If it does not, the edge
   proxy is not merely nicer — it is the only option for opencode clients.** Verify against opencode's
   MCP client source before Phase 2.
2. **Upstream or local?** `mempalace-edge` needs no core changes, so it belongs in this repo
   (`bin/` + `extensions/`). But `origin_host` metadata, per-wing ACL, the `kg_supersede`
   classification fix, and a `sync --refuse-shared` guard all want to go **upstream**
   (`github.com/MemPalace/mempalace`).
3. **Chunked drawers under merge.** Oversized content splits into `{drawer_id}_chunk_NNNNNN` with
   `parent_drawer_id`, and the add-time idempotency probe checks only the *last* chunk id — a
   partially transferred chunk set may look "already present" and stay truncated. Unverified; test
   before trusting bulk replay.
4. **`migrate.py` as a bootstrap tool.** `extract_drawers_from_sqlite()` reads `{id, document,
   metadata}` straight out of chroma's SQLite (bypassing the chromadb API) and re-`add`s them with ids
   and metadata preserved and **embeddings recomputed** (`migrate.py:326`) — the right shape for a
   one-shot "seed the primary from an existing palace". Unverified: `col.add` behaviour on **id
   collision into a non-empty target**. Test before relying on it. (`exporter.py` is markdown-only,
   lossy, and has **zero callers** — not a transfer format. `backups.py` is retention pruning only.)
5. **Does `_HTTP_REQUEST_LOCK` stay held for the duration of an MCP-triggered `mine`?** Strongly
   suggested by the code shape; if yes, a remote mine makes the primary unusable for its duration
   (another argument for §5).
6. **How does opencode-devbox learn the opt-in?** pi's transport choice is code (`createClient()`), so
   it reads `.env` for free. opencode's MCP registration is **static JSON** in
   `~/.config/opencode/opencode.json`, which per R1/R2 must be templated at container start rather
   than baked. Unknown: whether opencode-devbox's entrypoint has a config-templating step to hook, or
   whether the file is user-owned and bind-mounted (in which case the opt-in is a documented manual
   edit — acceptable, but say so). Also unknown whether the published `opencode-devbox` image ships
   mempalace at all; if not, edge mode there is host-side only until it does.

---

## 10. Evidence index

Re-verify without re-reading the package. Paths relative to
`/opt/uv-tools/mempalace/lib/python3.13/site-packages/mempalace/` (mempalace 3.6.0) unless noted.

| Claim | Where |
| --- | --- |
| Server auth/TLS/read-only | `cli.py:1448-1503`; `mcp_server.py:282-320`, `5205-5215`, `5284-5289` |
| Single global request lock | `mcp_server.py:5115`, `5346`, `5513` |
| KG path follows `--palace` flag only | `mcp_server.py:325`, `708-711`; `knowledge_graph.py:49` |
| KG DDL, no `(s,p,o)` uniqueness, open-fact guard | `knowledge_graph.py:163-178`, `305-313` |
| ID recipes | `ids.py:25`, `56`, `71`; diary at `mcp_server.py:3511-3514` |
| Tool classification (+ `kg_supersede` gap) | `service.py:29`, `54`, `72-84` |
| Write-routing seam | `write_routing.py:1-60` |
| Outbox prior art (queue DDL, token, retries) | `daemon.py` (`_init_db`, `ensure_token`, `MAX_ATTEMPTS`) |
| `sync` is destructive pruning | `sync.py:1-12` |
| WAL redacts + has no reader | `wal.py:74`, `_WAL_REDACT_KEYS` |
| Client-side embeddings | `backends/pgvector.py:6-8`; `embedding.py:6-11`; `_sidecar.py` |
| Dedup scoped by `source_file` | `dedup.py:get_source_groups` |
| Store location rules | `hallways.py:73,83`; `miner.py:701` |
| Mine lock (HOME-derived file) | `palace.py:1090`, `1123-1128` |
| Migrate as export primitive | `migrate.py:extract_drawers_from_sqlite`, `:326` |
| pi remote transport + fail-soft | `mempalace-toolkit/extensions/pi/mempalace.ts:11-12`, `87`, `108`, `390`, `629-641`, `665-673` (commit `96699f2`) |
| Server compose + port history | `pi-devbox/docker-compose.mempalace.yml`; `pi-devbox/CHANGELOG.md` v1.3.0; `docker-compose-repo/tor-ms22/pi-devbox/` (`df2c2ae`) |
| Existing opt-in convention (§1.2) | `pi-devbox/.env.example:12-23` ("MemPalace memory (local by default)", commented `MEMPALACE_REMOTE_URL`/`_TOKEN`); `pi-devbox/docker-compose.yml:79-83` (`devbox-palace` volume commented out) |
| opencode-devbox does not wire mempalace | `docker-compose-repo/{synlig,nyvaken,devbox-affection}/opencode-devbox/docker-compose.yml` — zero mempalace references in any |

## 11. See also

- [`ARCHITECTURE.md`](../ARCHITECTURE.md) — producer side (how the palace gets fed); §6 upstream roadmap
- [`extensions/pi/README.md`](../extensions/pi/README.md) — pi bridge internals
- [`SKILL.md`](../SKILL.md) — consumer-side protocol (search before answering, diary before exit)