ng-eventually/docs/migration-guide.md

# Migration guide — when real NextGraph matures

The whole point of this library: the consumer application already writes SDK-shaped
code, so when NextGraph ships cross-wallet reads, capabilities and inboxes, only this
lib changes. The consumer application's code does not change. This is the checklist.

## Guiding invariant

Every emulated piece has a 1:1 image in the real infra. Migration = swap the
emulation for the real primitive, remove the scaffold. If a piece of the emulation
has no clear target image, that is a drift signal (see
[`simulation.md`](./simulation.md)).

## Checklist

### 1. Emulated ReadCaps → real capabilities
The shape is already the target's (P1a): a `ReadCap` is the document's key, a
each identity holds a set of caps, and there is no read-ACL anywhere. So
this step swaps the *emulated* key for the real one, not the model:

- `caps.ts`'s per-identity record becomes the verifier's own local user storage —
  it was always the cache, not the register. The two durable registers we emulate
  (`readCap` on the store's Store branch, `link` on its User branch) become the real
  `AddRepo` / `AddLink` commits. Remove the emulation; the wallet and the branches
  already hold them.
- `nuri.ts`'s stand-in cap value — the constant `OK` — becomes the real
  `r:{base64url(serde_bare(ObjectRef))}`. It is **one function** (`mintCap`), because
  every path now READS a stored cap instead of recomputing one. `hasReadCap` /
  `targetOf` stay meaningful: the `r:` discriminant is upstream grammar, not ours.
- `shareCap(cap, toInbox)` becomes the native sealed delivery (`inbox_post_link`
  and `ContactDetails.read_cap`), and `inbox.read`'s inline absorption becomes the
  recipient's own verifier applying queued messages. **The consumer's call does not
  change.**
- `publishRepoLink` becomes `RepoLinkV0`.
- The read filter (`read-filter.ts`) and the possession gate in
  `read-model.readUnion` are then dead code — the broker only delivers documents
  whose cap the wallet holds. Remove them.
- The write guard (`ng-proxy.ts` `sparql_update` override) is a separate axis and
  is decorative today (every internal writer bypasses the proxy); it belongs to the
  P1b batch, not here.

The access unit is already the document (`@graph`), matching the native per-repo cap
model, so this is a key-material step, not a reshape.

### 2. Place documents in real native stores
Today `docCreate(..., undefined)` writes every document into the shared wallet's
private store, and the `public|protected|private` scope is a logical label
in the shim (see the two-axes section in [`simulation.md`](./simulation.md)).

- `doc_create` cannot target a non-private native store today — verified:
  `StoreRepo` is not JS-constructible from the SDK, so there is no way to pass
  a public/protected store as the create destination (`docCreate`'s trailing
  `store` arg is left `undefined` → private store). The private store works only
  because it opens without `RepoNotFound`.
- When the SDK lets you construct/target a native store, the migration adds a
  `getNativeStore(scope)`-style resolver returning the real store to pass as the
  `docCreate` destination, so the logical scope label becomes a real store
  placement. (No such helper exists yet — it is blocked on the SDK gap above.)
- At that point `store-registry.ts` maps `(account, scope)` to the user's real
  store NURI instead of a document in the shared wallet; the per-scope index
  document (the store-container emulation) is replaced by the store itself. The
  surface facing the consumer application (`createEntityDoc`, `listMyEntityDocs`,
  resolvers) is designed to survive that swap unchanged.

### 3. Drop the resolver / shim
The `sharedWalletShim` (account → 3 scope-document NURIs, held in a subscribable
doc-shim reached via a write-once pointer in the store-root — see
[`nextgraph-current-state.md`](./nextgraph-current-state.md) § *The pointer → doc-shim
indirection*) has no target equivalent — the target has no central directory. Remove
it entirely: `store-registry.ts`, `configureStoreRegistry`, the pointer + doc-shim
resolution, and the `pointerGuard` dep. Cross-wallet reads replace the fan-out;
per-user wallets replace the shared one.

### 4. Real inbox → drop the in-lib read emulation
Replace the emulated `inbox.ts` deposit (`docs.sparqlUpdate` into a shared-wallet
document) with the native `inbox_post_link` (proposed/future). On the read side the
recipient's own verifier unseals each queued sealed message and applies it inline
when it processes its inbox — there is no separate curator to build; the in-lib read
emulation simply goes away (see the deferred global-index note in the top-level
README and [`decisions/discovery-model.md`](./decisions/discovery-model.md)). The
single global index replaces the cross-account fan-out.

### 5. Retire the identity store → real per-user login
Remove `accounts.ts` (the `IdentityStore` that persists the identity id in
`localStorage`) and the app-level "Connexion" screen. The technical broker gate
becomes the real per-user login
(see [`decisions/shared-wallet-login-flow.md`](./decisions/shared-wallet-login-flow.md)).
The flow shape ("broker redirect → app") does not change.

### 6. Drop the isolation scaffold
`isolation.ts` (application-visibility scaffold) disappears against a
different piece of infra than the caps: real per-account wallets, and the
relationship concept the consumer application owns. Distinct axis from ReadCaps —
remove independently.

### 7. Remove the build alias — the client becomes the real SDK
The consumer application imports `@ng-org/web` / `@ng-org/orm` resolved to this lib
via a build alias during the polyfill period. Removing the alias makes those imports
resolve to the real SDK — the `ng`/`useShape`/`inbox` surface is SDK-identical, so
no consumer code changes. The one non-SDK call — `configure(...)` /
`@ng-eventually/client/polyfill` — is deleted. The lib itself disappears.

## The one break already taken: `declareConnections`

P1a broke the consumer once, deliberately and early, so that migration would not.
The old surface was an ACL held in memory, which forced the consumer to re-declare
every grant on every session (`declareConnections`). That call **disappears**: with
delivered caps the grant moves to the moment a connection is *accepted* — one
`shareCap(capFor(doc), theirInbox)` per document shared — and it persists, because
the delivery lives in the recipient's inbox rather than in a map that empties at
reload. There is no analogue of `protectedDocsOf` + the re-derivation loop.

This is a consumer **re-architecture**, not an API swap, and it is the price of
being coded against a model that will exist. Nothing else about the migration below
touches consumer code.

## What does not change

The consumer application's code. Shapes, screens, the *acts* of sharing
access, entity→scope mapping, the relationship graph — all injected, all untouched.
Migration is entirely inside this library plus removing the alias + the bootstrap
call. That asymmetry — a mature SDK face outward, all compensation inward — is the
library's reason to exist.