feat(wasmguest): guest capability stubs over host calls (WO-WZ-003)

Every CoreServices interface (core/plugin/deps.go) now has a guest-side stub
that marshals to the WO-WZ-001 capability messages and dispatches through the
generic host_call transport, so plugin service code compiles and runs
unchanged against content.Content, settings.Settings, plugin.PluginBridge, etc.

- core/plugin/wasmguest/caps/: one file per family (17 families, 38 methods),
  a var _ <iface> = (*stub)(nil) compile proof each, and NewCoreServices(call)
  assembling them. The transport is injected (CallFunc) so marshaling is
  natively testable; the wasm shim binds it to CallHost, DESCRIBE probes pass
  nil (capability calls fail cleanly instead of nil-panicking).
- Error mapping wraps AbiError with <family>.<method> context and maps
  DEADLINE_EXCEEDED onto context.DeadlineExceeded.
- RAGService.RegisterContentFetcher stays guest-side (RAGStub) for
  HOOK_RAG_FETCH dispatch; Query/OnContentChanged marshal out. dispatch.go and
  describe.go now source fetchers from the caps RAG stub.
- caps_roundtrip_test.go: fake transport + 76 deterministic golden payloads
  (family_method_{req,resp}.pb) covering 100% of families, plus error-mapping,
  deadline, nil-transport, and guest-side-fetcher tests. WO-WZ-006 replays the
  same goldens to prevent host/guest drift.
- Acceptance: testdata/fixture Load hook calls deps.Content/Settings/Bridge
  unchanged (compiles for wasip1); caps_wasmhost_test.go drives it end-to-end
  through a real wazero module + fake host_call table.
- Disposition table in docs/wasm-abi.md: every member stub | host-side
  (Pool, Interceptors, AppURL/MediaPath, CoreServiceBindings host-side).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/wasm-abi.md

@@ -97,6 +97,16 @@ A `packed` value of `0` means the callee could not even produce an envelope
 (allocation failure / trap); the caller treats it as
 `ABI_ERROR_CODE_INTERNAL` and discards the instance.
 
+> A logically-empty response is **not** packed `0`. A successful hook whose
+> response message has no set fields (e.g. `LoadResponse`/`UnloadResponse`)
+> proto-marshals to zero bytes; the guest still frames it as `(ptr, 0)` with a
+> real pointer so the host reads a valid empty envelope. `bn_invoke` never
+> returns packed `0` for a successful call. (Fixed in WO-WZ-003: the earlier
+> `len==0 → return 0` shortcut made every successful empty-response hook —
+> notably `HOOK_LOAD` — look like an INTERNAL failure and discard the
+> instance. The cms host in WO-WZ-006 must likewise not conflate a
+> zero-length payload with a missing envelope.)
+
 Instances are single-threaded: one `bn_invoke` at a time per instance;
 concurrency comes from the per-plugin instance pool.
 
@@ -146,7 +156,52 @@ each pair mirrors one Go interface method from `CoreServices` 1:1
 | `db` | `query`, `exec`, `tx_begin`, `tx_commit`, `tx_rollback` | `CoreServices.Pool` via the guest `database/sql` driver (`db.proto`) |
 
 The guest half of the SDK implements the existing Go interfaces as stubs
-marshaling to these calls, so plugin code compiles unchanged.
+marshaling to these calls (`core/plugin/wasmguest/caps/`, WO-WZ-003), so
+plugin code compiles unchanged. `caps.NewCoreServices(call)` assembles them;
+the wasm shim binds `call` to the real `host_call` transport, tests inject a
+fake, and a nil transport (DESCRIBE probes) fails every capability cleanly
+instead of nil-panicking.
+
+### Method disposition (every `CoreServices` member)
+
+No silent gaps: each member is either a guest stub or served host-side.
+
+| Member | Disposition |
+|---|---|
+| `Content` (7 methods) | **stub** — `caps/content.go` |
+| `Settings` / `SettingsUpdater` | **stub** — `caps/settings.go` (one value, both fields) |
+| `Gating` | **stub** — `caps/gating.go`; `EvaluateAccess` crosses but falls back to the pure `gating.EvaluateAccess` on transport error |
+| `Crypto` | **stub** — `caps/crypto.go` |
+| `Menus` | **stub** — `caps/menus.go` |
+| `Datasources` | **stub** — `caps/datasources.go` |
+| `PublicUsers` | **stub** — `caps/users.go` |
+| `Subscriptions` | **stub** — `caps/subscriptions.go` |
+| `Media` | **stub** — `caps/media.go` |
+| `ToolRegistry` + `AITextCall` | **stub** — `caps/ai.go` (`ai.tools.register` + `ai.text_call`; tool `Handler` stays guest-side) |
+| `EmailSender` | **stub** — `caps/email.go` |
+| `Bridge` | **stub** — `caps/bridge.go`; `RegisterService` forwards names only (value dropped), `GetService` reports availability but returns `nil` (a typed value cannot cross — open item) |
+| `ReviewSubmitter` | **stub** — `caps/reviews.go` |
+| `BadgeRefresher` | **stub** — `caps/badges.go` |
+| `JobRunner` | **stub** — `caps/jobs.go` |
+| `EmbeddingService` | **stub** — `caps/embeddings.go` |
+| `RAGService` | **stub** — `caps/rag.go`; `Query`/`OnContentChanged` cross, `RegisterContentFetcher` records guest-side for `HOOK_RAG_FETCH` |
+| `Pool` | **host-side** — the `db.*` driver (db.proto), per-plugin Postgres role |
+| `Interceptors` | **host-side** — the host builds the connect option chain; RBAC merges from `manifest.rbac_method_roles`. Auth context reaches the guest via `HttpRequest` headers (host-side interceptors already ran). |
+| `AppURL` / `MediaPath` | **host-side** — delivered once in `LoadRequest.host_config` |
+| `CoreServiceBindings` | **host-side** — static `manifest.core_service_bindings`; the host constructs and mounts the `http.Handler` (cannot cross the sandbox), so `caps` provides no stub |
+
+Interface satisfaction is proven at compile time by a `var _ <iface> =
+(*stub)(nil)` line per family; a wasip1 build of `testdata/fixture` (whose
+`Load` hook calls `deps.Content`/`deps.Settings`/`deps.Bridge` unchanged) plus
+the `TestWasmFixtureCapabilityRoundTrip` end-to-end wazero test prove the path
+crosses the ABI for real.
+
+Error mapping (`caps/caps.go`): a transport `AbiError` surfaces as a Go error
+wrapped with `<family>.<method>` context; an `ABI_ERROR_CODE_DEADLINE_EXCEEDED`
+reply is mapped onto `context.DeadlineExceeded` so `errors.Is` keeps working.
+Methods without an error channel (`Slugify`, `IsAvailable`, `EvaluateAccess`,
+`ToolRegistry.Register`, `Bridge.*`, `RAG.OnContentChanged`, …) degrade to the
+zero value / best-effort on transport failure.
 
 `CoreServices` members that do **not** cross as capability calls:
 

plugin/wasmguest/caps/ai.go

@@ -0,0 +1,52 @@
+package caps
+
+import (
+	"context"
+	"encoding/json"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/ai"
+)
+
+// aiStub implements ai.ToolRegistry (ai.tools.register) and backs the
+// CoreServices.AITextCall func field (ai.text_call).
+//
+// ToolDefinition.Handler stays guest-side: registration marshals only the
+// static descriptor. Host→guest tool execution is a runtime-WO concern
+// flagged in core/docs/wasm-abi.md.
+type aiStub struct{ base }
+
+var _ ai.ToolRegistry = (*aiStub)(nil)
+
+// Register has no error channel; a transport failure is dropped (the host
+// records nothing, matching the "best effort at load" contract).
+func (s *aiStub) Register(tool *ai.ToolDefinition) {
+	if tool == nil {
+		return
+	}
+	req := &abiv1.AiToolRegisterRequest{
+		Slug:        tool.Slug,
+		Name:        tool.Name,
+		Description: tool.Description,
+	}
+	if tool.ParameterSchema != nil {
+		if raw, err := json.Marshal(tool.ParameterSchema); err == nil {
+			req.ParameterSchemaJson = raw
+		}
+	}
+	_ = s.invoke(context.Background(), "tools.register", req, &abiv1.AiToolRegisterResponse{})
+}
+
+// textCall backs CoreServices.AITextCall.
+func (s *aiStub) textCall(ctx context.Context, taskKey, systemPrompt, userMessage string) (string, error) {
+	req := &abiv1.AiTextCallRequest{
+		TaskKey:      taskKey,
+		SystemPrompt: systemPrompt,
+		UserMessage:  userMessage,
+	}
+	resp := &abiv1.AiTextCallResponse{}
+	if err := s.invoke(ctx, "text_call", req, resp); err != nil {
+		return "", err
+	}
+	return resp.GetText(), nil
+}

plugin/wasmguest/caps/badges.go

@@ -0,0 +1,20 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/plugin"
+	"github.com/google/uuid"
+)
+
+// badgesStub implements plugin.BadgeRefresher over the badges.refresh_badges
+// capability call.
+type badgesStub struct{ base }
+
+var _ plugin.BadgeRefresher = (*badgesStub)(nil)
+
+func (s *badgesStub) RefreshBadges(ctx context.Context, tableID, rowID uuid.UUID) error {
+	req := &abiv1.BadgesRefreshBadgesRequest{TableId: tableID.String(), RowId: rowID.String()}
+	return s.invoke(ctx, "refresh_badges", req, &abiv1.BadgesRefreshBadgesResponse{})
+}

plugin/wasmguest/caps/bridge.go

@@ -0,0 +1,35 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/plugin"
+)
+
+// bridgeStub implements plugin.PluginBridge over bridge.* capability calls.
+//
+// The bridge shares in-process Go values today; across sandboxes only the
+// registration/lookup *surface* serializes — the service value itself cannot
+// cross. RegisterService therefore forwards only plugin/service names (the
+// value is dropped), and GetService returns nil (availability is checked but a
+// typed value cannot be reconstructed guest-side). Typed cross-plugin
+// invocation is an open ABI item (core/docs/wasm-abi.md).
+type bridgeStub struct{ base }
+
+var _ plugin.PluginBridge = (*bridgeStub)(nil)
+
+// RegisterService has no error channel; a transport failure is dropped.
+func (s *bridgeStub) RegisterService(pluginName, serviceName string, _ any) {
+	req := &abiv1.BridgeRegisterServiceRequest{PluginName: pluginName, ServiceName: serviceName}
+	_ = s.invoke(context.Background(), "register_service", req, &abiv1.BridgeRegisterServiceResponse{})
+}
+
+// GetService reports availability host-side but cannot return the concrete Go
+// value across the sandbox boundary, so it always returns nil. Callers using
+// plugin.GetServiceAs correctly observe (zero, false).
+func (s *bridgeStub) GetService(pluginName, serviceName string) any {
+	req := &abiv1.BridgeGetServiceRequest{PluginName: pluginName, ServiceName: serviceName}
+	_ = s.invoke(context.Background(), "get_service", req, &abiv1.BridgeGetServiceResponse{})
+	return nil
+}

plugin/wasmguest/caps/caps.go

@@ -0,0 +1,89 @@
+// Package caps implements every CoreServices capability interface
+// (core/plugin/deps.go) as a guest-side stub that marshals to the WO-WZ-001
+// capability messages (abiv1) and dispatches them through a single generic
+// guest→host transport. Plugin code keeps compiling and calling against
+// content.Content, settings.Settings, plugin.PluginBridge, etc. — unchanged —
+// while the concrete work now happens host-side over the wasm ABI.
+//
+// # The transport seam
+//
+// A capability call is "marshal a family request, invoke
+// '<family>.<method>', unmarshal the reply". That transport is injected as a
+// CallFunc so the marshaling logic in this package stays natively testable
+// (a fake CallFunc in caps_roundtrip_test.go), while the wasm guest shim
+// (package wasmguest, wasip1) binds the real host_call-backed transport. This
+// package deliberately does NOT import wasmguest: wasmguest imports caps (to
+// assemble the services and reach the guest-side RAG fetcher registry), so the
+// dependency only points one way.
+//
+// # Method disposition
+//
+// Every CoreServices member is either a stub here or documented host-side in
+// core/docs/wasm-abi.md §"Capability calls". Host-side members (no stub):
+// Pool (db.* driver), Interceptors (host connect options), AppURL/MediaPath
+// (delivered in LoadRequest.host_config), and CoreServiceBindings (static
+// manifest.core_service_bindings the host mounts). RAGService.
+// RegisterContentFetcher is guest-side (records fetchers for HOOK_RAG_FETCH);
+// its Query/OnContentChanged marshal out.
+package caps
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"google.golang.org/protobuf/proto"
+)
+
+// CallFunc is the guest→host capability transport: marshal req, invoke the
+// host with method "<family>.<method>", and unmarshal the reply into resp. It
+// matches wasmguest.CallHost exactly so the wasip1 shim can bind it directly.
+// A nil CallFunc (native builds, DESCRIBE probes) makes every capability call
+// fail cleanly with errNoHost rather than panic.
+type CallFunc func(method string, req, resp proto.Message) error
+
+// abiCoded is implemented by transport errors that carry an ABI error code
+// (wasmguest.HostError does). It lets the stubs map a DEADLINE_EXCEEDED reply
+// onto context.DeadlineExceeded without importing wasmguest.
+type abiCoded interface {
+	AbiErrorCode() abiv1.AbiErrorCode
+}
+
+// base is embedded by every family stub: the family name and the transport.
+type base struct {
+	family string
+	call   CallFunc
+}
+
+// invoke performs one capability call and maps any transport error with
+// family/method context. ctx is honored up front — an already-cancelled or
+// expired context short-circuits before crossing the boundary — but is not
+// forwarded to the transport itself (the host enforces the invoke deadline
+// carried in InvokeRequest.deadline_ms; see core/docs/wasm-abi.md).
+func (b base) invoke(ctx context.Context, method string, req, resp proto.Message) error {
+	if b.call == nil {
+		return fmt.Errorf("%s.%s: no host transport bound (native build)", b.family, method)
+	}
+	if ctx != nil {
+		if err := ctx.Err(); err != nil {
+			return fmt.Errorf("%s.%s: %w", b.family, method, err)
+		}
+	}
+	return b.mapErr(method, b.call(b.family+"."+method, req, resp))
+}
+
+// mapErr wraps a transport error with family/method context so plugin logs
+// stay legible, and translates an ABI deadline into context.DeadlineExceeded
+// so callers' errors.Is(err, context.DeadlineExceeded) keeps working.
+func (b base) mapErr(method string, err error) error {
+	if err == nil {
+		return nil
+	}
+	var coded abiCoded
+	if errors.As(err, &coded) &&
+		coded.AbiErrorCode() == abiv1.AbiErrorCode_ABI_ERROR_CODE_DEADLINE_EXCEEDED {
+		return fmt.Errorf("%s.%s: %w: %v", b.family, method, context.DeadlineExceeded, err)
+	}
+	return fmt.Errorf("%s.%s: %w", b.family, method, err)
+}

plugin/wasmguest/caps/caps_roundtrip_test.go

@@ -0,0 +1,677 @@
+package caps
+
+import (
+	"context"
+	"errors"
+	"flag"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/ai"
+	"git.dev.alexdunmow.com/block/core/gating"
+	"git.dev.alexdunmow.com/block/core/plugin"
+	"github.com/google/uuid"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/types/known/timestamppb"
+)
+
+// -update regenerates the golden capability payloads. WO-WZ-006 (cms host)
+// replays these SAME goldens to prove the host and guest agree on the wire, so
+// they must stay deterministic (proto marshaled with Deterministic=true).
+var update = flag.Bool("update", false, "regenerate golden capability payloads")
+
+const goldenDir = "testdata/golden"
+
+// Fixed IDs keep the goldens stable across runs.
+var (
+	idUser   = uuid.MustParse("11111111-1111-1111-1111-111111111111")
+	idAuthor = uuid.MustParse("22222222-2222-2222-2222-222222222222")
+	idMenu   = uuid.MustParse("33333333-3333-3333-3333-333333333333")
+	idItem   = uuid.MustParse("44444444-4444-4444-4444-444444444444")
+	idParent = uuid.MustParse("55555555-5555-5555-5555-555555555555")
+	idBucket = uuid.MustParse("66666666-6666-6666-6666-666666666666")
+	idTier   = uuid.MustParse("77777777-7777-7777-7777-777777777777")
+	idPlan   = uuid.MustParse("88888888-8888-8888-8888-888888888888")
+	idMedia  = uuid.MustParse("99999999-9999-9999-9999-999999999999")
+	idTable  = uuid.MustParse("aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa")
+	idRow    = uuid.MustParse("bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb")
+	planTime = time.Date(2026, 7, 3, 12, 0, 0, 0, time.UTC)
+)
+
+func goldenPath(name string) string { return filepath.Join(goldenDir, name+".pb") }
+
+func detMarshal(t *testing.T, m proto.Message) []byte {
+	t.Helper()
+	b, err := proto.MarshalOptions{Deterministic: true}.Marshal(m)
+	if err != nil {
+		t.Fatalf("marshal: %v", err)
+	}
+	return b
+}
+
+// fakeTransport is the swapped-in CallFunc: it checks the request the stub
+// produced against a golden, then feeds back a canned response golden.
+type fakeTransport struct {
+	t          *testing.T
+	name       string        // golden basename for the current call
+	cannedResp proto.Message // synthesizes the resp golden under -update
+	err        error         // returned instead of a response (error-mapping cases)
+	gotMethod  string
+}
+
+func (f *fakeTransport) call(method string, req, resp proto.Message) error {
+	f.gotMethod = method
+	reqBytes := detMarshal(f.t, req)
+	reqPath := goldenPath(f.name + "_req")
+	if *update {
+		writeGolden(f.t, reqPath, reqBytes)
+	} else {
+		want, err := os.ReadFile(reqPath)
+		if err != nil {
+			f.t.Fatalf("%s: read request golden (run -update?): %v", f.name, err)
+		}
+		if !equalProto(f.t, want, reqBytes, req) {
+			f.t.Errorf("%s: request payload drifted from golden %s", f.name, reqPath)
+		}
+	}
+	if f.err != nil {
+		return f.err
+	}
+	respPath := goldenPath(f.name + "_resp")
+	if *update {
+		respBytes := detMarshal(f.t, f.cannedResp)
+		writeGolden(f.t, respPath, respBytes)
+		if err := proto.Unmarshal(respBytes, resp); err != nil {
+			f.t.Fatalf("%s: unmarshal canned resp: %v", f.name, err)
+		}
+		return nil
+	}
+	respBytes, err := os.ReadFile(respPath)
+	if err != nil {
+		f.t.Fatalf("%s: read response golden (run -update?): %v", f.name, err)
+	}
+	if err := proto.Unmarshal(respBytes, resp); err != nil {
+		f.t.Fatalf("%s: unmarshal response golden: %v", f.name, err)
+	}
+	return nil
+}
+
+func writeGolden(t *testing.T, path string, b []byte) {
+	t.Helper()
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		t.Fatalf("mkdir golden: %v", err)
+	}
+	if err := os.WriteFile(path, b, 0o644); err != nil {
+		t.Fatalf("write golden: %v", err)
+	}
+}
+
+// equalProto compares two serializations by decoding both into fresh messages
+// of the same type, so semantically-equal encodings still match.
+func equalProto(t *testing.T, want, got []byte, sample proto.Message) bool {
+	t.Helper()
+	a := sample.ProtoReflect().New().Interface()
+	b := sample.ProtoReflect().New().Interface()
+	if err := proto.Unmarshal(want, a); err != nil {
+		t.Fatalf("unmarshal want: %v", err)
+	}
+	if err := proto.Unmarshal(got, b); err != nil {
+		t.Fatalf("unmarshal got: %v", err)
+	}
+	return proto.Equal(a, b)
+}
+
+// capCase is one capability round trip: set up the fake, call the stub through
+// the assembled CoreServices, and assert both the wire method and the decoded
+// Go result.
+type capCase struct {
+	name       string
+	wantMethod string
+	resp       proto.Message
+	run        func(t *testing.T, cs plugin.CoreServices)
+}
+
+func TestCapabilityRoundTrip(t *testing.T) {
+	ctx := context.Background()
+	f := &fakeTransport{t: t}
+	cs := NewCoreServices(f.call)
+
+	cases := []capCase{
+		// --- content ---
+		{
+			name: "content_get_author_profile", wantMethod: "content.get_author_profile",
+			resp: &abiv1.ContentGetAuthorProfileResponse{Author: &abiv1.AuthorProfile{
+				Id: idAuthor.String(), Name: "Ada", Slug: "ada", Bio: "hi",
+				AvatarUrl: "https://x/a.png", Website: "https://ada.dev",
+				SocialLinks: map[string]string{"x": "@ada", "gh": "ada"},
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Content.GetAuthorProfile(ctx, idAuthor)
+				if err != nil {
+					t.Fatal(err)
+				}
+				if got.ID != idAuthor || got.Name != "Ada" || got.SocialLinks["x"] != "@ada" {
+					t.Errorf("author = %+v", got)
+				}
+			},
+		},
+		{
+			name: "content_get_page", wantMethod: "content.get_page",
+			resp: &abiv1.ContentGetPageResponse{Page: &abiv1.PageInfo{Id: idAuthor.String(), Slug: "about", Title: "About Us"}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Content.GetPage(ctx, "about")
+				if err != nil {
+					t.Fatal(err)
+				}
+				if got.Slug != "about" || got.Title != "About Us" {
+					t.Errorf("page = %+v", got)
+				}
+			},
+		},
+		{
+			name: "content_get_post", wantMethod: "content.get_post",
+			resp: &abiv1.ContentGetPostResponse{Post: &abiv1.PostInfo{
+				Id: idAuthor.String(), Slug: "hello", Title: "Hello", Excerpt: "hi",
+				FeaturedImageUrl: "media:x", AuthorId: idAuthor.String(),
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Content.GetPost(ctx, "hello")
+				if err != nil {
+					t.Fatal(err)
+				}
+				if got.Title != "Hello" || got.AuthorID != idAuthor {
+					t.Errorf("post = %+v", got)
+				}
+			},
+		},
+		{
+			name: "content_slugify", wantMethod: "content.slugify",
+			resp: &abiv1.ContentSlugifyResponse{Slug: "hello-world"},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if got := cs.Content.Slugify("Hello World"); got != "hello-world" {
+					t.Errorf("slug = %q", got)
+				}
+			},
+		},
+		{
+			name: "content_block_note_to_html", wantMethod: "content.block_note_to_html",
+			resp: &abiv1.ContentBlockNoteToHtmlResponse{Html: "<p>hi</p>"},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if got := cs.Content.BlockNoteToHTML(ctx, map[string]any{"type": "doc"}); got != "<p>hi</p>" {
+					t.Errorf("html = %q", got)
+				}
+			},
+		},
+		{
+			name: "content_generate_excerpt", wantMethod: "content.generate_excerpt",
+			resp: &abiv1.ContentGenerateExcerptResponse{Excerpt: "short"},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if got := cs.Content.GenerateExcerpt("<p>long text</p>", 5); got != "short" {
+					t.Errorf("excerpt = %q", got)
+				}
+			},
+		},
+		{
+			name: "content_strip_html", wantMethod: "content.strip_html",
+			resp: &abiv1.ContentStripHtmlResponse{Text: "plain"},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if got := cs.Content.StripHTML("<b>plain</b>"); got != "plain" {
+					t.Errorf("text = %q", got)
+				}
+			},
+		},
+		// --- settings ---
+		{
+			name: "settings_get_site_settings", wantMethod: "settings.get_site_settings",
+			resp: &abiv1.SettingsGetSiteSettingsResponse{SettingsJson: []byte(`{"site_name":"Fixture","theme":"dark"}`)},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				m, err := cs.Settings.GetSiteSettings(ctx)
+				if err != nil {
+					t.Fatal(err)
+				}
+				if m["site_name"] != "Fixture" {
+					t.Errorf("settings = %+v", m)
+				}
+			},
+		},
+		{
+			name: "settings_get_plugin_settings", wantMethod: "settings.get_plugin_settings",
+			resp: &abiv1.SettingsGetPluginSettingsResponse{SettingsJson: []byte(`{"enabled":true}`)},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				m, err := cs.Settings.GetPluginSettings(ctx, "symposium")
+				if err != nil {
+					t.Fatal(err)
+				}
+				if m["enabled"] != true {
+					t.Errorf("plugin settings = %+v", m)
+				}
+			},
+		},
+		{
+			name: "settings_update_site_setting", wantMethod: "settings.update_site_setting",
+			resp: &abiv1.SettingsUpdateSiteSettingResponse{},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if err := cs.SettingsUpdater.UpdateSiteSetting(ctx, "theme", "light"); err != nil {
+					t.Fatal(err)
+				}
+			},
+		},
+		// --- gating ---
+		{
+			name: "gating_get_subscriber_tier_level", wantMethod: "gating.get_subscriber_tier_level",
+			resp: &abiv1.GatingGetSubscriberTierLevelResponse{Level: 3},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Gating.GetSubscriberTierLevel(ctx, idUser)
+				if err != nil {
+					t.Fatal(err)
+				}
+				if got != 3 {
+					t.Errorf("level = %d", got)
+				}
+			},
+		},
+		{
+			name: "gating_evaluate_access", wantMethod: "gating.evaluate_access",
+			resp: &abiv1.GatingEvaluateAccessResponse{Result: &abiv1.AccessResult{
+				HasAccess: false, TeaserMode: "soft", TeaserPercent: 20, RequiredLevel: 2,
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got := cs.Gating.EvaluateAccess(1, &gating.AccessRule{MinTierLevel: 2, TeaserMode: "soft", TeaserPercent: 20})
+				if got.HasAccess || got.TeaserMode != "soft" || got.RequiredLevel != 2 {
+					t.Errorf("access = %+v", got)
+				}
+			},
+		},
+		// --- crypto ---
+		{
+			name: "crypto_encrypt_secret", wantMethod: "crypto.encrypt_secret",
+			resp: &abiv1.CryptoEncryptSecretResponse{Ciphertext: "enc:abc"},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Crypto.EncryptSecret("plain")
+				if err != nil || got != "enc:abc" {
+					t.Errorf("ciphertext = %q err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "crypto_decrypt_secret", wantMethod: "crypto.decrypt_secret",
+			resp: &abiv1.CryptoDecryptSecretResponse{Plaintext: "plain"},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Crypto.DecryptSecret("enc:abc")
+				if err != nil || got != "plain" {
+					t.Errorf("plaintext = %q err = %v", got, err)
+				}
+			},
+		},
+		// --- menus ---
+		{
+			name: "menus_get_menu_by_name", wantMethod: "menus.get_menu_by_name",
+			resp: &abiv1.MenusGetMenuByNameResponse{Menu: &abiv1.Menu{Id: idMenu.String(), Name: "main"}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Menus.GetMenuByName(ctx, "main")
+				if err != nil || got.ID != idMenu || got.Name != "main" {
+					t.Errorf("menu = %+v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "menus_get_menu_items", wantMethod: "menus.get_menu_items",
+			resp: &abiv1.MenusGetMenuItemsResponse{Items: []*abiv1.MenuItem{{
+				Id: idItem.String(), MenuId: idMenu.String(), Label: "Home", Url: "/",
+				PageSlug: "home", ParentId: proto.String(idParent.String()), SortOrder: 1,
+				OpenInNewTab: true, CssClass: "nav", ItemType: "link", Icon: "home",
+			}}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Menus.GetMenuItems(ctx, idMenu)
+				if err != nil || len(got) != 1 {
+					t.Fatalf("items = %+v err = %v", got, err)
+				}
+				it := got[0]
+				if it.ID != idItem || it.ParentID == nil || *it.ParentID != idParent || !it.OpenInNewTab {
+					t.Errorf("item = %+v", it)
+				}
+			},
+		},
+		// --- datasources ---
+		{
+			name: "datasources_resolve_bucket", wantMethod: "datasources.resolve_bucket",
+			resp: &abiv1.DatasourcesResolveBucketResponse{Result: &abiv1.DatasourceResult{
+				ItemsJson: []byte(`[{"id":1},{"id":2}]`), Total: 2, MetaJson: []byte(`{"page":1}`),
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Datasources.ResolveBucket(ctx, idBucket)
+				if err != nil || got.Total != 2 || len(got.Items) != 2 || got.Meta["page"] != float64(1) {
+					t.Errorf("result = %+v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "datasources_resolve_bucket_by_key", wantMethod: "datasources.resolve_bucket_by_key",
+			resp: &abiv1.DatasourcesResolveBucketByKeyResponse{Result: &abiv1.DatasourceResult{
+				ItemsJson: []byte(`[]`), Total: 0,
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Datasources.ResolveBucketByKey(ctx, "featured")
+				if err != nil || got.Total != 0 {
+					t.Errorf("result = %+v err = %v", got, err)
+				}
+			},
+		},
+		// --- users ---
+		{
+			name: "users_get_by_username", wantMethod: "users.get_by_username",
+			resp: &abiv1.UsersGetByUsernameResponse{User: &abiv1.PublicUserProfile{
+				Id: idUser.String(), Email: "u@x.com", Username: "u", DisplayName: "U",
+				AvatarUrl: "a", Bio: "b", EmailVerified: true, Role: "member",
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.PublicUsers.GetByUsername(ctx, "u")
+				if err != nil || got.ID != idUser || !got.EmailVerified {
+					t.Errorf("user = %+v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "users_get_by_id", wantMethod: "users.get_by_id",
+			resp: &abiv1.UsersGetByIdResponse{User: &abiv1.PublicUserProfile{Id: idUser.String(), Username: "u"}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.PublicUsers.GetByID(ctx, idUser)
+				if err != nil || got.Username != "u" {
+					t.Errorf("user = %+v err = %v", got, err)
+				}
+			},
+		},
+		// --- subscriptions ---
+		{
+			name: "subscriptions_get_user_tier_level", wantMethod: "subscriptions.get_user_tier_level",
+			resp: &abiv1.SubscriptionsGetUserTierLevelResponse{TierLevel: &abiv1.TierLevel{Level: 5, Features: []byte(`{"a":1}`)}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Subscriptions.GetUserTierLevel(ctx, idUser)
+				if err != nil || got.Level != 5 || string(got.Features) != `{"a":1}` {
+					t.Errorf("tier level = %+v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "subscriptions_get_tier_by_slug", wantMethod: "subscriptions.get_tier_by_slug",
+			resp: &abiv1.SubscriptionsGetTierBySlugResponse{Tier: &abiv1.Tier{
+				Id: idTier.String(), Name: "Gold", Slug: "gold", Level: 3, Description: "d",
+				Features: []byte(`{}`), IsDefault: true, Position: 2,
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Subscriptions.GetTierBySlug(ctx, "gold")
+				if err != nil || got.ID != idTier || got.Level != 3 || !got.IsDefault {
+					t.Errorf("tier = %+v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "subscriptions_list_tiers", wantMethod: "subscriptions.list_tiers",
+			resp: &abiv1.SubscriptionsListTiersResponse{Tiers: []*abiv1.Tier{
+				{Id: idTier.String(), Name: "Gold", Slug: "gold", Level: 3},
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Subscriptions.ListTiers(ctx)
+				if err != nil || len(got) != 1 || got[0].Slug != "gold" {
+					t.Errorf("tiers = %+v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "subscriptions_list_active_plans", wantMethod: "subscriptions.list_active_plans",
+			resp: &abiv1.SubscriptionsListActivePlansResponse{Plans: []*abiv1.Plan{{
+				Id: idPlan.String(), TierId: idTier.String(), BillingInterval: "month",
+				Amount: 4900, Currency: "usd", IsActive: true, CreatedAt: timestamppb.New(planTime),
+			}}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Subscriptions.ListActivePlans(ctx, idTier)
+				if err != nil || len(got) != 1 {
+					t.Fatalf("plans = %+v err = %v", got, err)
+				}
+				p := got[0]
+				if p.ID != idPlan || p.Amount != 4900 || !p.CreatedAt.Equal(planTime) {
+					t.Errorf("plan = %+v", p)
+				}
+			},
+		},
+		// --- media ---
+		{
+			name: "media_deposit", wantMethod: "media.deposit",
+			resp: &abiv1.MediaDepositResponse{Id: idMedia.String(), Ref: "media:" + idMedia.String(), Created: true},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.Media.Deposit(ctx, plugin.MediaDeposit{
+					ID: idMedia, Filename: "hero.jpg", Data: []byte("bytes"), AltText: "alt", Folder: "f", Source: "plugin",
+				})
+				if err != nil || got.ID != idMedia || !got.Created {
+					t.Errorf("media = %+v err = %v", got, err)
+				}
+			},
+		},
+		// --- email ---
+		{
+			name: "email_send", wantMethod: "email.send",
+			resp: &abiv1.EmailSendResponse{},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if err := cs.EmailSender.Send("to@x.com", "Subj", "Body"); err != nil {
+					t.Fatal(err)
+				}
+			},
+		},
+		// --- ai ---
+		{
+			name: "ai_text_call", wantMethod: "ai.text_call",
+			resp: &abiv1.AiTextCallResponse{Text: "generated"},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.AITextCall(ctx, "summarize", "sys", "user")
+				if err != nil || got != "generated" {
+					t.Errorf("text = %q err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "ai_tools_register", wantMethod: "ai.tools.register",
+			resp: &abiv1.AiToolRegisterResponse{},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				cs.ToolRegistry.Register(&ai.ToolDefinition{
+					Slug: "lookup", Name: "Lookup", Description: "d",
+					ParameterSchema: map[string]any{"type": "object"},
+				})
+			},
+		},
+		// --- bridge ---
+		{
+			name: "bridge_register_service", wantMethod: "bridge.register_service",
+			resp: &abiv1.BridgeRegisterServiceResponse{},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				cs.Bridge.RegisterService("symposium", "search", struct{}{})
+			},
+		},
+		{
+			name: "bridge_get_service", wantMethod: "bridge.get_service",
+			resp: &abiv1.BridgeGetServiceResponse{Available: true},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if got := cs.Bridge.GetService("symposium", "search"); got != nil {
+					t.Errorf("get_service crossed a value: %v (want nil)", got)
+				}
+			},
+		},
+		// --- jobs ---
+		{
+			name: "jobs_submit", wantMethod: "jobs.submit",
+			resp: &abiv1.JobsSubmitResponse{},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if err := cs.JobRunner.Submit(ctx, "reindex", []byte(`{"full":true}`)); err != nil {
+					t.Fatal(err)
+				}
+			},
+		},
+		// --- embeddings ---
+		{
+			name: "embeddings_generate_embedding", wantMethod: "embeddings.generate_embedding",
+			resp: &abiv1.EmbeddingsGenerateEmbeddingResponse{Embedding: []float32{0.1, 0.2, 0.3}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.EmbeddingService.GenerateEmbedding(ctx, "text")
+				if err != nil || len(got) != 3 || got[0] != 0.1 {
+					t.Errorf("embedding = %v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "embeddings_embed_content", wantMethod: "embeddings.embed_content",
+			resp: &abiv1.EmbeddingsEmbedContentResponse{Embedded: true},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.EmbeddingService.EmbedContent(ctx, "post", idRow, "text")
+				if err != nil || !got {
+					t.Errorf("embedded = %v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "embeddings_is_available", wantMethod: "embeddings.is_available",
+			resp: &abiv1.EmbeddingsIsAvailableResponse{Available: true},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if !cs.EmbeddingService.IsAvailable() {
+					t.Errorf("is_available = false")
+				}
+			},
+		},
+		// --- rag ---
+		{
+			name: "rag_query", wantMethod: "rag.query",
+			resp: &abiv1.RagQueryResponse{Results: []*abiv1.RagResult{
+				{Content: "chunk", Score: 0.9, Metadata: map[string]string{"src": "post"}},
+			}},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.RAGService.Query(ctx, "q", 5)
+				if err != nil || len(got) != 1 || got[0].Score != 0.9 || got[0].Metadata["src"] != "post" {
+					t.Errorf("rag = %+v err = %v", got, err)
+				}
+			},
+		},
+		{
+			name: "rag_on_content_changed", wantMethod: "rag.on_content_changed",
+			resp: &abiv1.RagOnContentChangedResponse{},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				cs.RAGService.OnContentChanged(ctx, "post", idRow)
+			},
+		},
+		// --- reviews ---
+		{
+			name: "reviews_submit_review", wantMethod: "reviews.submit_review",
+			resp: &abiv1.ReviewsSubmitReviewResponse{ReviewId: "rev-1"},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				got, err := cs.ReviewSubmitter.SubmitReview(ctx, plugin.SubmitReviewParams{
+					TableID: idTable, RowID: idRow, OverallRating: 4, ReviewText: "good",
+					Ratings: map[string]any{"food": 5}, Photos: []string{"media:1"},
+				})
+				if err != nil || got != "rev-1" {
+					t.Errorf("review id = %q err = %v", got, err)
+				}
+			},
+		},
+		// --- badges ---
+		{
+			name: "badges_refresh_badges", wantMethod: "badges.refresh_badges",
+			resp: &abiv1.BadgesRefreshBadgesResponse{},
+			run: func(t *testing.T, cs plugin.CoreServices) {
+				if err := cs.BadgeRefresher.RefreshBadges(ctx, idTable, idRow); err != nil {
+					t.Fatal(err)
+				}
+			},
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			f.name = tc.name
+			f.cannedResp = tc.resp
+			f.err = nil
+			f.gotMethod = ""
+			tc.run(t, cs)
+			if f.gotMethod != tc.wantMethod {
+				t.Errorf("method = %q, want %q", f.gotMethod, tc.wantMethod)
+			}
+		})
+	}
+}
+
+// fakeAbiErr is a transport error carrying an ABI code, like wasmguest.HostError.
+type fakeAbiErr struct {
+	code abiv1.AbiErrorCode
+	msg  string
+}
+
+func (e *fakeAbiErr) Error() string                    { return e.msg }
+func (e *fakeAbiErr) AbiErrorCode() abiv1.AbiErrorCode { return e.code }
+
+func TestErrorMappingCarriesFamilyMethod(t *testing.T) {
+	f := &fakeTransport{t: t, err: &fakeAbiErr{code: abiv1.AbiErrorCode_ABI_ERROR_CODE_PERMISSION_DENIED, msg: "denied"}}
+	cs := NewCoreServices(f.call)
+	f.name = "content_get_page" // reuse the request golden for the compare
+
+	_, err := cs.Content.GetPage(context.Background(), "about")
+	if err == nil {
+		t.Fatal("want error")
+	}
+	if got := err.Error(); !strings.Contains(got, "content.get_page") || !strings.Contains(got, "denied") {
+		t.Errorf("error %q lacks family/method or message", got)
+	}
+}
+
+func TestErrorMappingDeadlineBecomesContextDeadline(t *testing.T) {
+	f := &fakeTransport{t: t, err: &fakeAbiErr{code: abiv1.AbiErrorCode_ABI_ERROR_CODE_DEADLINE_EXCEEDED, msg: "deadline"}}
+	cs := NewCoreServices(f.call)
+	f.name = "crypto_encrypt_secret"
+
+	_, err := cs.Crypto.EncryptSecret("plain")
+	if err == nil {
+		t.Fatal("want error")
+	}
+	if !errors.Is(err, context.DeadlineExceeded) {
+		t.Errorf("error %q does not wrap context.DeadlineExceeded", err)
+	}
+	if !strings.Contains(err.Error(), "crypto.encrypt_secret") {
+		t.Errorf("error %q lacks family/method", err)
+	}
+}
+
+func TestNilTransportFailsCleanly(t *testing.T) {
+	cs := NewCoreServices(nil)
+	_, err := cs.Content.GetPage(context.Background(), "about")
+	if err == nil || !strings.Contains(err.Error(), "no host transport") {
+		t.Errorf("nil transport error = %v", err)
+	}
+}
+
+// TestRAGRegisterContentFetcherStaysGuestSide verifies RegisterContentFetcher
+// records fetchers locally (no host call) for HOOK_RAG_FETCH dispatch.
+func TestRAGRegisterContentFetcherStaysGuestSide(t *testing.T) {
+	f := &fakeTransport{t: t}
+	cs := NewCoreServices(f.call)
+	rag, ok := cs.RAGService.(*RAGStub)
+	if !ok {
+		t.Fatalf("RAGService is %T, want *RAGStub", cs.RAGService)
+	}
+	called := false
+	rag.RegisterContentFetcher("post", func(context.Context, uuid.UUID) (string, string, error) {
+		called = true
+		return "T", "body", nil
+	})
+	if f.gotMethod != "" {
+		t.Errorf("RegisterContentFetcher made a host call %q", f.gotMethod)
+	}
+	if types := rag.FetcherTypes(); len(types) != 1 || types[0] != "post" {
+		t.Errorf("fetcher types = %v", types)
+	}
+	fetcher, ok := rag.Fetcher("post")
+	if !ok {
+		t.Fatal("fetcher not found")
+	}
+	if _, _, _ = fetcher(context.Background(), idRow); !called {
+		t.Error("registered fetcher not invoked")
+	}
+}

plugin/wasmguest/caps/content.go

@@ -0,0 +1,105 @@
+package caps
+
+import (
+	"context"
+	"encoding/json"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/content"
+	"github.com/google/uuid"
+)
+
+// contentStub implements content.Content over content.* capability calls.
+type contentStub struct{ base }
+
+var _ content.Content = (*contentStub)(nil)
+
+func (s *contentStub) GetAuthorProfile(ctx context.Context, id uuid.UUID) (*content.AuthorProfile, error) {
+	resp := &abiv1.ContentGetAuthorProfileResponse{}
+	if err := s.invoke(ctx, "get_author_profile", &abiv1.ContentGetAuthorProfileRequest{Id: id.String()}, resp); err != nil {
+		return nil, err
+	}
+	a := resp.GetAuthor()
+	if a == nil {
+		return nil, nil
+	}
+	return &content.AuthorProfile{
+		ID:          parseUUID(a.GetId()),
+		Name:        a.GetName(),
+		Slug:        a.GetSlug(),
+		Bio:         a.GetBio(),
+		AvatarURL:   a.GetAvatarUrl(),
+		Website:     a.GetWebsite(),
+		SocialLinks: a.GetSocialLinks(),
+	}, nil
+}
+
+func (s *contentStub) GetPage(ctx context.Context, slug string) (*content.PageInfo, error) {
+	resp := &abiv1.ContentGetPageResponse{}
+	if err := s.invoke(ctx, "get_page", &abiv1.ContentGetPageRequest{Slug: slug}, resp); err != nil {
+		return nil, err
+	}
+	p := resp.GetPage()
+	if p == nil {
+		return nil, nil
+	}
+	return &content.PageInfo{ID: parseUUID(p.GetId()), Slug: p.GetSlug(), Title: p.GetTitle()}, nil
+}
+
+func (s *contentStub) GetPost(ctx context.Context, slug string) (*content.PostInfo, error) {
+	resp := &abiv1.ContentGetPostResponse{}
+	if err := s.invoke(ctx, "get_post", &abiv1.ContentGetPostRequest{Slug: slug}, resp); err != nil {
+		return nil, err
+	}
+	p := resp.GetPost()
+	if p == nil {
+		return nil, nil
+	}
+	return &content.PostInfo{
+		ID:               parseUUID(p.GetId()),
+		Slug:             p.GetSlug(),
+		Title:            p.GetTitle(),
+		Excerpt:          p.GetExcerpt(),
+		FeaturedImageURL: p.GetFeaturedImageUrl(),
+		AuthorID:         parseUUID(p.GetAuthorId()),
+	}, nil
+}
+
+// Slugify has no error channel in the interface; a transport failure degrades
+// to the empty string (the caller treats an empty slug as "unavailable").
+func (s *contentStub) Slugify(text string) string {
+	resp := &abiv1.ContentSlugifyResponse{}
+	if err := s.invoke(context.Background(), "slugify", &abiv1.ContentSlugifyRequest{Text: text}, resp); err != nil {
+		return ""
+	}
+	return resp.GetSlug()
+}
+
+func (s *contentStub) BlockNoteToHTML(ctx context.Context, doc map[string]any) string {
+	docJSON, err := json.Marshal(doc)
+	if err != nil {
+		return ""
+	}
+	resp := &abiv1.ContentBlockNoteToHtmlResponse{}
+	if err := s.invoke(ctx, "block_note_to_html", &abiv1.ContentBlockNoteToHtmlRequest{DocJson: docJSON}, resp); err != nil {
+		return ""
+	}
+	return resp.GetHtml()
+}
+
+func (s *contentStub) GenerateExcerpt(html string, maxLen int) string {
+	resp := &abiv1.ContentGenerateExcerptResponse{}
+	req := &abiv1.ContentGenerateExcerptRequest{Html: html, MaxLen: int32(maxLen)}
+	if err := s.invoke(context.Background(), "generate_excerpt", req, resp); err != nil {
+		return ""
+	}
+	return resp.GetExcerpt()
+}
+
+func (s *contentStub) StripHTML(str string) string {
+	resp := &abiv1.ContentStripHtmlResponse{}
+	if err := s.invoke(context.Background(), "strip_html", &abiv1.ContentStripHtmlRequest{Html: str}, resp); err != nil {
+		return ""
+	}
+	return resp.GetText()
+}

plugin/wasmguest/caps/coreservices.go

@@ -0,0 +1,49 @@
+package caps
+
+import (
+	"git.dev.alexdunmow.com/block/core/plugin"
+)
+
+// NewCoreServices assembles the guest-side CoreServices value plugins receive
+// in their Load/HTTP/Job hooks: every capability interface is a stub that
+// marshals to a "<family>.<method>" host call over the injected transport.
+//
+// The transport is injected (not a package global) so the marshaling logic is
+// natively testable with a fake CallFunc; the wasm shim (package wasmguest,
+// wasip1) passes its host_call-backed CallHost. A nil call yields stubs that
+// fail every capability with a clear "no host transport" error — the shape
+// used by DESCRIBE probes, which never reach a live host.
+//
+// Members intentionally left zero because they do NOT cross as capability
+// calls (all documented in core/docs/wasm-abi.md §"Capability calls"):
+//
+//   - Pool                → the db.* driver messages (db.proto)
+//   - Interceptors        → host-side connect options; RBAC from the manifest
+//   - MediaPath / AppURL  → delivered in LoadRequest.host_config at load
+//   - CoreServiceBindings → static manifest.core_service_bindings; host mounts
+func NewCoreServices(call CallFunc) plugin.CoreServices {
+	settings := &settingsStub{base{family: "settings", call: call}}
+	ai := &aiStub{base{family: "ai", call: call}}
+
+	return plugin.CoreServices{
+		Content:          &contentStub{base{family: "content", call: call}},
+		Settings:         settings,
+		SettingsUpdater:  settings,
+		Gating:           &gatingStub{base{family: "gating", call: call}},
+		Crypto:           &cryptoStub{base{family: "crypto", call: call}},
+		Menus:            &menusStub{base{family: "menus", call: call}},
+		Datasources:      &datasourcesStub{base{family: "datasources", call: call}},
+		PublicUsers:      &usersStub{base{family: "users", call: call}},
+		Subscriptions:    &subscriptionsStub{base{family: "subscriptions", call: call}},
+		Media:            &mediaStub{base{family: "media", call: call}},
+		ToolRegistry:     ai,
+		AITextCall:       ai.textCall,
+		EmailSender:      &emailStub{base{family: "email", call: call}},
+		Bridge:           &bridgeStub{base{family: "bridge", call: call}},
+		ReviewSubmitter:  &reviewsStub{base{family: "reviews", call: call}},
+		BadgeRefresher:   &badgesStub{base{family: "badges", call: call}},
+		JobRunner:        &jobsStub{base{family: "jobs", call: call}},
+		EmbeddingService: &embeddingsStub{base{family: "embeddings", call: call}},
+		RAGService:       NewRAGStub(call),
+	}
+}

plugin/wasmguest/caps/crypto.go

@@ -0,0 +1,30 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/crypto"
+)
+
+// cryptoStub implements crypto.Crypto over crypto.* capability calls. The
+// interface takes no context; host calls run under the invoke deadline.
+type cryptoStub struct{ base }
+
+var _ crypto.Crypto = (*cryptoStub)(nil)
+
+func (s *cryptoStub) EncryptSecret(plaintext string) (string, error) {
+	resp := &abiv1.CryptoEncryptSecretResponse{}
+	if err := s.invoke(context.Background(), "encrypt_secret", &abiv1.CryptoEncryptSecretRequest{Plaintext: plaintext}, resp); err != nil {
+		return "", err
+	}
+	return resp.GetCiphertext(), nil
+}
+
+func (s *cryptoStub) DecryptSecret(ciphertext string) (string, error) {
+	resp := &abiv1.CryptoDecryptSecretResponse{}
+	if err := s.invoke(context.Background(), "decrypt_secret", &abiv1.CryptoDecryptSecretRequest{Ciphertext: ciphertext}, resp); err != nil {
+		return "", err
+	}
+	return resp.GetPlaintext(), nil
+}

plugin/wasmguest/caps/datasources.go

@@ -0,0 +1,46 @@
+package caps
+
+import (
+	"context"
+	"encoding/json"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/datasources"
+	"github.com/google/uuid"
+)
+
+// datasourcesStub implements datasources.Datasources over datasources.*
+// capability calls. Items ([]any) and Meta (map[string]any) cross as JSON.
+type datasourcesStub struct{ base }
+
+var _ datasources.Datasources = (*datasourcesStub)(nil)
+
+func (s *datasourcesStub) ResolveBucket(ctx context.Context, bucketID uuid.UUID) (*datasources.Result, error) {
+	resp := &abiv1.DatasourcesResolveBucketResponse{}
+	req := &abiv1.DatasourcesResolveBucketRequest{BucketId: bucketID.String()}
+	if err := s.invoke(ctx, "resolve_bucket", req, resp); err != nil {
+		return nil, err
+	}
+	return datasourceResultFromProto(resp.GetResult()), nil
+}
+
+func (s *datasourcesStub) ResolveBucketByKey(ctx context.Context, bucketKey string) (*datasources.Result, error) {
+	resp := &abiv1.DatasourcesResolveBucketByKeyResponse{}
+	req := &abiv1.DatasourcesResolveBucketByKeyRequest{BucketKey: bucketKey}
+	if err := s.invoke(ctx, "resolve_bucket_by_key", req, resp); err != nil {
+		return nil, err
+	}
+	return datasourceResultFromProto(resp.GetResult()), nil
+}
+
+func datasourceResultFromProto(r *abiv1.DatasourceResult) *datasources.Result {
+	if r == nil {
+		return nil
+	}
+	out := &datasources.Result{Total: int(r.GetTotal())}
+	if items := r.GetItemsJson(); len(items) > 0 {
+		_ = json.Unmarshal(items, &out.Items)
+	}
+	out.Meta = unmarshalMap(r.GetMetaJson())
+	return out
+}

plugin/wasmguest/caps/email.go

@@ -0,0 +1,19 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/plugin"
+)
+
+// emailStub implements plugin.EmailSender over the email.send capability call.
+// The interface takes no context; the call runs under the invoke deadline.
+type emailStub struct{ base }
+
+var _ plugin.EmailSender = (*emailStub)(nil)
+
+func (s *emailStub) Send(to, subject, body string) error {
+	req := &abiv1.EmailSendRequest{To: to, Subject: subject, Body: body}
+	return s.invoke(context.Background(), "send", req, &abiv1.EmailSendResponse{})
+}

plugin/wasmguest/caps/embeddings.go

@@ -0,0 +1,46 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/plugin"
+	"github.com/google/uuid"
+)
+
+// embeddingsStub implements plugin.EmbeddingService over embeddings.*
+// capability calls.
+type embeddingsStub struct{ base }
+
+var _ plugin.EmbeddingService = (*embeddingsStub)(nil)
+
+func (s *embeddingsStub) GenerateEmbedding(ctx context.Context, text string) ([]float32, error) {
+	resp := &abiv1.EmbeddingsGenerateEmbeddingResponse{}
+	req := &abiv1.EmbeddingsGenerateEmbeddingRequest{Text: text}
+	if err := s.invoke(ctx, "generate_embedding", req, resp); err != nil {
+		return nil, err
+	}
+	return resp.GetEmbedding(), nil
+}
+
+func (s *embeddingsStub) EmbedContent(ctx context.Context, sourceType string, sourceID uuid.UUID, text string) (bool, error) {
+	resp := &abiv1.EmbeddingsEmbedContentResponse{}
+	req := &abiv1.EmbeddingsEmbedContentRequest{
+		SourceType: sourceType,
+		SourceId:   sourceID.String(),
+		Text:       text,
+	}
+	if err := s.invoke(ctx, "embed_content", req, resp); err != nil {
+		return false, err
+	}
+	return resp.GetEmbedded(), nil
+}
+
+// IsAvailable has no error channel; a transport failure reports unavailable.
+func (s *embeddingsStub) IsAvailable() bool {
+	resp := &abiv1.EmbeddingsIsAvailableResponse{}
+	if err := s.invoke(context.Background(), "is_available", &abiv1.EmbeddingsIsAvailableRequest{}, resp); err != nil {
+		return false
+	}
+	return resp.GetAvailable()
+}

plugin/wasmguest/caps/gating.go

@@ -0,0 +1,51 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/gating"
+	"github.com/google/uuid"
+)
+
+// gatingStub implements gating.Gating over gating.* capability calls.
+type gatingStub struct{ base }
+
+var _ gating.Gating = (*gatingStub)(nil)
+
+func (s *gatingStub) GetSubscriberTierLevel(ctx context.Context, userID uuid.UUID) (int, error) {
+	resp := &abiv1.GatingGetSubscriberTierLevelResponse{}
+	req := &abiv1.GatingGetSubscriberTierLevelRequest{UserId: userID.String()}
+	if err := s.invoke(ctx, "get_subscriber_tier_level", req, resp); err != nil {
+		return 0, err
+	}
+	return int(resp.GetLevel()), nil
+}
+
+// EvaluateAccess mirrors the host's decision. The rule evaluation is a pure,
+// deterministic function (gating.EvaluateAccess) so the interface exposes no
+// error channel; the call still crosses the boundary to keep host and guest
+// on identical logic, and falls back to the local pure function if the
+// transport is unavailable.
+func (s *gatingStub) EvaluateAccess(userTierLevel int, rule *gating.AccessRule) gating.AccessResult {
+	req := &abiv1.GatingEvaluateAccessRequest{UserTierLevel: int32(userTierLevel)}
+	if rule != nil {
+		req.Rule = &abiv1.AccessRule{
+			MinTierLevel:   int32(rule.MinTierLevel),
+			OverrideTierId: rule.OverrideTierID,
+			TeaserMode:     rule.TeaserMode,
+			TeaserPercent:  int32(rule.TeaserPercent),
+		}
+	}
+	resp := &abiv1.GatingEvaluateAccessResponse{}
+	if err := s.invoke(context.Background(), "evaluate_access", req, resp); err != nil {
+		return gating.EvaluateAccess(userTierLevel, rule)
+	}
+	r := resp.GetResult()
+	return gating.AccessResult{
+		HasAccess:     r.GetHasAccess(),
+		TeaserMode:    r.GetTeaserMode(),
+		TeaserPercent: int(r.GetTeaserPercent()),
+		RequiredLevel: int(r.GetRequiredLevel()),
+	}
+}

plugin/wasmguest/caps/jobs.go

@@ -0,0 +1,18 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/plugin"
+)
+
+// jobsStub implements plugin.JobRunner over the jobs.submit capability call.
+type jobsStub struct{ base }
+
+var _ plugin.JobRunner = (*jobsStub)(nil)
+
+func (s *jobsStub) Submit(ctx context.Context, jobType string, config []byte) error {
+	req := &abiv1.JobsSubmitRequest{JobType: jobType, ConfigJson: config}
+	return s.invoke(ctx, "submit", req, &abiv1.JobsSubmitResponse{})
+}

plugin/wasmguest/caps/media.go

@@ -0,0 +1,36 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/plugin"
+	"github.com/google/uuid"
+)
+
+// mediaStub implements plugin.Media over the media.deposit capability call.
+type mediaStub struct{ base }
+
+var _ plugin.Media = (*mediaStub)(nil)
+
+func (s *mediaStub) Deposit(ctx context.Context, deposit plugin.MediaDeposit) (plugin.MediaResult, error) {
+	req := &abiv1.MediaDepositRequest{
+		Filename: deposit.Filename,
+		Data:     deposit.Data,
+		AltText:  deposit.AltText,
+		Folder:   deposit.Folder,
+		Source:   deposit.Source,
+	}
+	if deposit.ID != uuid.Nil {
+		req.Id = deposit.ID.String()
+	}
+	resp := &abiv1.MediaDepositResponse{}
+	if err := s.invoke(ctx, "deposit", req, resp); err != nil {
+		return plugin.MediaResult{}, err
+	}
+	return plugin.MediaResult{
+		ID:      parseUUID(resp.GetId()),
+		Ref:     resp.GetRef(),
+		Created: resp.GetCreated(),
+	}, nil
+}

plugin/wasmguest/caps/menus.go

@@ -0,0 +1,55 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/menus"
+	"github.com/google/uuid"
+)
+
+// menusStub implements menus.Menus over menus.* capability calls.
+type menusStub struct{ base }
+
+var _ menus.Menus = (*menusStub)(nil)
+
+func (s *menusStub) GetMenuByName(ctx context.Context, name string) (*menus.Menu, error) {
+	resp := &abiv1.MenusGetMenuByNameResponse{}
+	if err := s.invoke(ctx, "get_menu_by_name", &abiv1.MenusGetMenuByNameRequest{Name: name}, resp); err != nil {
+		return nil, err
+	}
+	m := resp.GetMenu()
+	if m == nil {
+		return nil, nil
+	}
+	return &menus.Menu{ID: parseUUID(m.GetId()), Name: m.GetName()}, nil
+}
+
+func (s *menusStub) GetMenuItems(ctx context.Context, menuID uuid.UUID) ([]menus.MenuItem, error) {
+	resp := &abiv1.MenusGetMenuItemsResponse{}
+	req := &abiv1.MenusGetMenuItemsRequest{MenuId: menuID.String()}
+	if err := s.invoke(ctx, "get_menu_items", req, resp); err != nil {
+		return nil, err
+	}
+	items := make([]menus.MenuItem, 0, len(resp.GetItems()))
+	for _, it := range resp.GetItems() {
+		mi := menus.MenuItem{
+			ID:           parseUUID(it.GetId()),
+			MenuID:       parseUUID(it.GetMenuId()),
+			Label:        it.GetLabel(),
+			URL:          it.GetUrl(),
+			PageSlug:     it.GetPageSlug(),
+			SortOrder:    it.GetSortOrder(),
+			OpenInNewTab: it.GetOpenInNewTab(),
+			CssClass:     it.GetCssClass(),
+			ItemType:     it.GetItemType(),
+			Icon:         it.GetIcon(),
+		}
+		if it.ParentId != nil {
+			pid := parseUUID(it.GetParentId())
+			mi.ParentID = &pid
+		}
+		items = append(items, mi)
+	}
+	return items, nil
+}

plugin/wasmguest/caps/rag.go

@@ -0,0 +1,78 @@
+package caps
+
+import (
+	"context"
+	"sort"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/plugin"
+	"github.com/google/uuid"
+)
+
+// RAGStub implements plugin.RAGService. Query and OnContentChanged marshal out
+// to rag.* capability calls, while RegisterContentFetcher records the fetcher
+// guest-side: the host re-indexes by inverting the call as a HOOK_RAG_FETCH
+// callback, so the wasm shim reads the recorded fetchers to dispatch it. The
+// stub is exported so the shim can reach FetcherTypes/Fetcher.
+type RAGStub struct {
+	base
+	fetchers map[string]plugin.ContentFetcher
+}
+
+var _ plugin.RAGService = (*RAGStub)(nil)
+
+// NewRAGStub builds a RAG stub with the given transport. A nil transport
+// (DESCRIBE probe, native build) still records fetchers so their content
+// types can be captured into the manifest.
+func NewRAGStub(call CallFunc) *RAGStub {
+	return &RAGStub{
+		base:     base{family: "rag", call: call},
+		fetchers: make(map[string]plugin.ContentFetcher),
+	}
+}
+
+func (s *RAGStub) RegisterContentFetcher(contentType string, fetcher plugin.ContentFetcher) {
+	s.fetchers[contentType] = fetcher
+}
+
+func (s *RAGStub) Query(ctx context.Context, query string, limit int) ([]plugin.RAGResult, error) {
+	req := &abiv1.RagQueryRequest{Query: query, Limit: int32(limit)}
+	resp := &abiv1.RagQueryResponse{}
+	if err := s.invoke(ctx, "query", req, resp); err != nil {
+		return nil, err
+	}
+	results := make([]plugin.RAGResult, 0, len(resp.GetResults()))
+	for _, r := range resp.GetResults() {
+		results = append(results, plugin.RAGResult{
+			Content:  r.GetContent(),
+			Score:    r.GetScore(),
+			Metadata: r.GetMetadata(),
+		})
+	}
+	return results, nil
+}
+
+// OnContentChanged has no error channel; a transport failure is dropped (the
+// host will re-index on its own schedule regardless).
+func (s *RAGStub) OnContentChanged(ctx context.Context, contentType string, contentID uuid.UUID) {
+	req := &abiv1.RagOnContentChangedRequest{ContentType: contentType, ContentId: contentID.String()}
+	_ = s.invoke(ctx, "on_content_changed", req, &abiv1.RagOnContentChangedResponse{})
+}
+
+// Fetcher returns the content fetcher registered for a content type, for
+// HOOK_RAG_FETCH dispatch by the wasm shim.
+func (s *RAGStub) Fetcher(contentType string) (plugin.ContentFetcher, bool) {
+	f, ok := s.fetchers[contentType]
+	return f, ok
+}
+
+// FetcherTypes lists the registered content-fetcher types in sorted order
+// (deterministic manifest capture).
+func (s *RAGStub) FetcherTypes() []string {
+	types := make([]string, 0, len(s.fetchers))
+	for k := range s.fetchers {
+		types = append(types, k)
+	}
+	sort.Strings(types)
+	return types
+}

plugin/wasmguest/caps/reviews.go

@@ -0,0 +1,35 @@
+package caps
+
+import (
+	"context"
+	"encoding/json"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/plugin"
+)
+
+// reviewsStub implements plugin.ReviewSubmitter over the reviews.submit_review
+// capability call.
+type reviewsStub struct{ base }
+
+var _ plugin.ReviewSubmitter = (*reviewsStub)(nil)
+
+func (s *reviewsStub) SubmitReview(ctx context.Context, params plugin.SubmitReviewParams) (string, error) {
+	req := &abiv1.ReviewsSubmitReviewRequest{
+		TableId:       params.TableID.String(),
+		RowId:         params.RowID.String(),
+		OverallRating: params.OverallRating,
+		ReviewText:    params.ReviewText,
+		Photos:        params.Photos,
+	}
+	if params.Ratings != nil {
+		if raw, err := json.Marshal(params.Ratings); err == nil {
+			req.RatingsJson = raw
+		}
+	}
+	resp := &abiv1.ReviewsSubmitReviewResponse{}
+	if err := s.invoke(ctx, "submit_review", req, resp); err != nil {
+		return "", err
+	}
+	return resp.GetReviewId(), nil
+}

plugin/wasmguest/caps/settings.go

@@ -0,0 +1,44 @@
+package caps
+
+import (
+	"context"
+	"encoding/json"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/settings"
+)
+
+// settingsStub implements both settings.Settings and settings.Updater over
+// settings.* capability calls. One instance backs both CoreServices fields.
+type settingsStub struct{ base }
+
+var (
+	_ settings.Settings = (*settingsStub)(nil)
+	_ settings.Updater  = (*settingsStub)(nil)
+)
+
+func (s *settingsStub) GetSiteSettings(ctx context.Context) (map[string]any, error) {
+	resp := &abiv1.SettingsGetSiteSettingsResponse{}
+	if err := s.invoke(ctx, "get_site_settings", &abiv1.SettingsGetSiteSettingsRequest{}, resp); err != nil {
+		return nil, err
+	}
+	return unmarshalMap(resp.GetSettingsJson()), nil
+}
+
+func (s *settingsStub) GetPluginSettings(ctx context.Context, pluginName string) (map[string]any, error) {
+	resp := &abiv1.SettingsGetPluginSettingsResponse{}
+	req := &abiv1.SettingsGetPluginSettingsRequest{PluginName: pluginName}
+	if err := s.invoke(ctx, "get_plugin_settings", req, resp); err != nil {
+		return nil, err
+	}
+	return unmarshalMap(resp.GetSettingsJson()), nil
+}
+
+func (s *settingsStub) UpdateSiteSetting(ctx context.Context, key string, value any) error {
+	valueJSON, err := json.Marshal(value)
+	if err != nil {
+		return err
+	}
+	req := &abiv1.SettingsUpdateSiteSettingRequest{Key: key, ValueJson: valueJSON}
+	return s.invoke(ctx, "update_site_setting", req, &abiv1.SettingsUpdateSiteSettingResponse{})
+}

plugin/wasmguest/caps/subscriptions.go

@@ -0,0 +1,91 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/subscriptions"
+	"github.com/google/uuid"
+)
+
+// subscriptionsStub implements subscriptions.Subscriptions over
+// subscriptions.* capability calls.
+type subscriptionsStub struct{ base }
+
+var _ subscriptions.Subscriptions = (*subscriptionsStub)(nil)
+
+func (s *subscriptionsStub) GetUserTierLevel(ctx context.Context, userID uuid.UUID) (*subscriptions.TierLevel, error) {
+	resp := &abiv1.SubscriptionsGetUserTierLevelResponse{}
+	req := &abiv1.SubscriptionsGetUserTierLevelRequest{UserId: userID.String()}
+	if err := s.invoke(ctx, "get_user_tier_level", req, resp); err != nil {
+		return nil, err
+	}
+	tl := resp.GetTierLevel()
+	if tl == nil {
+		return nil, nil
+	}
+	return &subscriptions.TierLevel{Level: int(tl.GetLevel()), Features: tl.GetFeatures()}, nil
+}
+
+func (s *subscriptionsStub) GetTierBySlug(ctx context.Context, slug string) (*subscriptions.Tier, error) {
+	resp := &abiv1.SubscriptionsGetTierBySlugResponse{}
+	req := &abiv1.SubscriptionsGetTierBySlugRequest{Slug: slug}
+	if err := s.invoke(ctx, "get_tier_by_slug", req, resp); err != nil {
+		return nil, err
+	}
+	t := resp.GetTier()
+	if t == nil {
+		return nil, nil
+	}
+	tier := tierFromProto(t)
+	return &tier, nil
+}
+
+func (s *subscriptionsStub) ListTiers(ctx context.Context) ([]subscriptions.Tier, error) {
+	resp := &abiv1.SubscriptionsListTiersResponse{}
+	if err := s.invoke(ctx, "list_tiers", &abiv1.SubscriptionsListTiersRequest{}, resp); err != nil {
+		return nil, err
+	}
+	tiers := make([]subscriptions.Tier, 0, len(resp.GetTiers()))
+	for _, t := range resp.GetTiers() {
+		tiers = append(tiers, tierFromProto(t))
+	}
+	return tiers, nil
+}
+
+func (s *subscriptionsStub) ListActivePlans(ctx context.Context, tierID uuid.UUID) ([]subscriptions.Plan, error) {
+	resp := &abiv1.SubscriptionsListActivePlansResponse{}
+	req := &abiv1.SubscriptionsListActivePlansRequest{TierId: tierID.String()}
+	if err := s.invoke(ctx, "list_active_plans", req, resp); err != nil {
+		return nil, err
+	}
+	plans := make([]subscriptions.Plan, 0, len(resp.GetPlans()))
+	for _, p := range resp.GetPlans() {
+		plan := subscriptions.Plan{
+			ID:              parseUUID(p.GetId()),
+			TierID:          parseUUID(p.GetTierId()),
+			BillingInterval: p.GetBillingInterval(),
+			Amount:          p.GetAmount(),
+			Currency:        p.GetCurrency(),
+			IsActive:        p.GetIsActive(),
+		}
+		if ts := p.GetCreatedAt(); ts != nil {
+			plan.CreatedAt = ts.AsTime()
+		}
+		plans = append(plans, plan)
+	}
+	return plans, nil
+}
+
+func tierFromProto(t *abiv1.Tier) subscriptions.Tier {
+	return subscriptions.Tier{
+		ID:          parseUUID(t.GetId()),
+		Name:        t.GetName(),
+		Slug:        t.GetSlug(),
+		Level:       int(t.GetLevel()),
+		Description: t.GetDescription(),
+		Features:    t.GetFeatures(),
+		IsDefault:   t.GetIsDefault(),
+		Position:    int(t.GetPosition()),
+	}
+}

plugin/wasmguest/caps/testdata/golden/ai_text_call_req.pb

@@ -0,0 +1,2 @@
+
+	summarizesysuser

plugin/wasmguest/caps/testdata/golden/ai_text_call_resp.pb

@@ -0,0 +1,2 @@
+
+	generated

plugin/wasmguest/caps/testdata/golden/ai_tools_register_req.pb

@@ -0,0 +1,2 @@
+
+lookupLookup
d"{"type":"object"}

plugin/wasmguest/caps/testdata/golden/badges_refresh_badges_req.pb

@@ -0,0 +1,2 @@
+
+$aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa$bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb

plugin/wasmguest/caps/testdata/golden/bridge_get_service_req.pb

@@ -0,0 +1,2 @@
+
+	symposiumsearch

plugin/wasmguest/caps/testdata/golden/bridge_get_service_resp.pb

@@ -0,0 +1 @@
+

plugin/wasmguest/caps/testdata/golden/bridge_register_service_req.pb

@@ -0,0 +1,2 @@
+
+	symposiumsearch

plugin/wasmguest/caps/testdata/golden/content_block_note_to_html_req.pb

@@ -0,0 +1,2 @@
+
+{"type":"doc"}

plugin/wasmguest/caps/testdata/golden/content_block_note_to_html_resp.pb

@@ -0,0 +1,2 @@
+
+	<p>hi</p>

plugin/wasmguest/caps/testdata/golden/content_generate_excerpt_req.pb

@@ -0,0 +1,2 @@
+
+<p>long text</p>

plugin/wasmguest/caps/testdata/golden/content_generate_excerpt_resp.pb

@@ -0,0 +1,2 @@
+
+short

plugin/wasmguest/caps/testdata/golden/content_get_author_profile_req.pb

@@ -0,0 +1,2 @@
+
+$22222222-2222-2222-2222-222222222222

plugin/wasmguest/caps/testdata/golden/content_get_author_profile_resp.pb

@@ -0,0 +1,5 @@
+
+l
+$22222222-2222-2222-2222-222222222222Adaada"hi*https://x/a.png2https://ada.dev:	
+ghada:	
+
x@ada

plugin/wasmguest/caps/testdata/golden/content_get_page_req.pb

@@ -0,0 +1,2 @@
+
+about

plugin/wasmguest/caps/testdata/golden/content_get_page_resp.pb

@@ -0,0 +1,3 @@
+
+7
+$22222222-2222-2222-2222-222222222222aboutAbout Us

plugin/wasmguest/caps/testdata/golden/content_get_post_req.pb

@@ -0,0 +1,2 @@
+
+hello

plugin/wasmguest/caps/testdata/golden/content_get_post_resp.pb

@@ -0,0 +1,3 @@
+
+g
+$22222222-2222-2222-2222-222222222222helloHello"hi*media:x2$22222222-2222-2222-2222-222222222222

plugin/wasmguest/caps/testdata/golden/content_slugify_req.pb

@@ -0,0 +1,2 @@
+
+Hello World

plugin/wasmguest/caps/testdata/golden/content_slugify_resp.pb

@@ -0,0 +1,2 @@
+
+hello-world

plugin/wasmguest/caps/testdata/golden/content_strip_html_req.pb

@@ -0,0 +1,2 @@
+
+<b>plain</b>

plugin/wasmguest/caps/testdata/golden/content_strip_html_resp.pb

@@ -0,0 +1,2 @@
+
+plain

plugin/wasmguest/caps/testdata/golden/crypto_decrypt_secret_req.pb

@@ -0,0 +1,2 @@
+
+enc:abc

plugin/wasmguest/caps/testdata/golden/crypto_decrypt_secret_resp.pb

@@ -0,0 +1,2 @@
+
+plain

plugin/wasmguest/caps/testdata/golden/crypto_encrypt_secret_req.pb

@@ -0,0 +1,2 @@
+
+plain

plugin/wasmguest/caps/testdata/golden/crypto_encrypt_secret_resp.pb

@@ -0,0 +1,2 @@
+
+enc:abc

plugin/wasmguest/caps/testdata/golden/datasources_resolve_bucket_by_key_req.pb

@@ -0,0 +1,2 @@
+
+featured

plugin/wasmguest/caps/testdata/golden/datasources_resolve_bucket_by_key_resp.pb

@@ -0,0 +1,3 @@
+
+
+[]

plugin/wasmguest/caps/testdata/golden/datasources_resolve_bucket_req.pb

@@ -0,0 +1,2 @@
+
+$66666666-6666-6666-6666-666666666666

plugin/wasmguest/caps/testdata/golden/datasources_resolve_bucket_resp.pb

@@ -0,0 +1,4 @@
+
+#
+[{"id":1},{"id":2}]
+{"page":1}

plugin/wasmguest/caps/testdata/golden/email_send_req.pb

@@ -0,0 +1,2 @@
+
+to@x.comSubjBody

plugin/wasmguest/caps/testdata/golden/embeddings_embed_content_req.pb

@@ -0,0 +1,2 @@
+
+post$bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbbtext

plugin/wasmguest/caps/testdata/golden/embeddings_embed_content_resp.pb

@@ -0,0 +1 @@
+

plugin/wasmguest/caps/testdata/golden/embeddings_generate_embedding_req.pb

@@ -0,0 +1,2 @@
+
+text

plugin/wasmguest/caps/testdata/golden/embeddings_generate_embedding_resp.pb

@@ -0,0 +1,2 @@
+
+<0C><><EFBFBD>=<3D><>L><3E><><EFBFBD>>

plugin/wasmguest/caps/testdata/golden/embeddings_is_available_resp.pb

@@ -0,0 +1 @@
+

plugin/wasmguest/caps/testdata/golden/gating_evaluate_access_req.pb

@@ -0,0 +1,2 @@
+

+soft 

plugin/wasmguest/caps/testdata/golden/gating_evaluate_access_resp.pb

@@ -0,0 +1,3 @@
+
+
+soft 

plugin/wasmguest/caps/testdata/golden/gating_get_subscriber_tier_level_req.pb

@@ -0,0 +1,2 @@
+
+$11111111-1111-1111-1111-111111111111

plugin/wasmguest/caps/testdata/golden/gating_get_subscriber_tier_level_resp.pb

@@ -0,0 +1 @@
+

plugin/wasmguest/caps/testdata/golden/jobs_submit_req.pb

@@ -0,0 +1,2 @@
+
+reindex
{"full":true}

plugin/wasmguest/caps/testdata/golden/media_deposit_req.pb

@@ -0,0 +1,2 @@
+
+$99999999-9999-9999-9999-999999999999hero.jpgbytes"alt*
f2plugin

plugin/wasmguest/caps/testdata/golden/media_deposit_resp.pb

@@ -0,0 +1,2 @@
+
+$99999999-9999-9999-9999-999999999999*media:99999999-9999-9999-9999-999999999999

plugin/wasmguest/caps/testdata/golden/menus_get_menu_by_name_req.pb

@@ -0,0 +1,2 @@
+
+main

plugin/wasmguest/caps/testdata/golden/menus_get_menu_by_name_resp.pb

@@ -0,0 +1,3 @@
+
+,
+$33333333-3333-3333-3333-333333333333main

plugin/wasmguest/caps/testdata/golden/menus_get_menu_items_req.pb

@@ -0,0 +1,2 @@
+
+$33333333-3333-3333-3333-333333333333

plugin/wasmguest/caps/testdata/golden/menus_get_menu_items_resp.pb

@@ -0,0 +1,3 @@
+
+–

+$44444444-4444-4444-4444-444444444444$33333333-3333-3333-3333-333333333333Home"
/*home2$55555555-5555-5555-5555-5555555555558
@
JnavRlinkZhome

plugin/wasmguest/caps/testdata/golden/rag_on_content_changed_req.pb

@@ -0,0 +1,2 @@
+
+post$bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb

plugin/wasmguest/caps/testdata/golden/rag_query_req.pb

@@ -0,0 +1,2 @@
+
+
q

plugin/wasmguest/caps/testdata/golden/rag_query_resp.pb

@@ -0,0 +1,4 @@
+
+
+chunkÍĚĚĚĚĚě?
+srcpost

plugin/wasmguest/caps/testdata/golden/reviews_submit_review_req.pb

@@ -0,0 +1,3 @@
+
+$aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa$bbbbbbbb-bbbb-bbbb-bbbb-bbbbbbbbbbbb"good*
+{"food":5}2media:1

plugin/wasmguest/caps/testdata/golden/reviews_submit_review_resp.pb

@@ -0,0 +1,2 @@
+
+rev-1

plugin/wasmguest/caps/testdata/golden/settings_get_plugin_settings_req.pb

@@ -0,0 +1,2 @@
+
+	symposium

plugin/wasmguest/caps/testdata/golden/settings_get_plugin_settings_resp.pb

@@ -0,0 +1,2 @@
+
+{"enabled":true}

plugin/wasmguest/caps/testdata/golden/settings_get_site_settings_resp.pb

@@ -0,0 +1,2 @@
+
+&{"site_name":"Fixture","theme":"dark"}

plugin/wasmguest/caps/testdata/golden/settings_update_site_setting_req.pb

@@ -0,0 +1,2 @@
+
+theme"light"

plugin/wasmguest/caps/testdata/golden/subscriptions_get_tier_by_slug_req.pb

@@ -0,0 +1,2 @@
+
+gold

plugin/wasmguest/caps/testdata/golden/subscriptions_get_tier_by_slug_resp.pb

@@ -0,0 +1,3 @@
+
+?
+$77777777-7777-7777-7777-777777777777Goldgold *
d2{}8
@

plugin/wasmguest/caps/testdata/golden/subscriptions_get_user_tier_level_req.pb

@@ -0,0 +1,2 @@
+
+$11111111-1111-1111-1111-111111111111

plugin/wasmguest/caps/testdata/golden/subscriptions_get_user_tier_level_resp.pb

@@ -0,0 +1,2 @@
+
+{"a":1}

plugin/wasmguest/caps/testdata/golden/subscriptions_list_active_plans_req.pb

@@ -0,0 +1,2 @@
+
+$77777777-7777-7777-7777-777777777777

plugin/wasmguest/caps/testdata/golden/subscriptions_list_active_plans_resp.pb

@@ -0,0 +1,3 @@
+
+e
+$88888888-8888-8888-8888-888888888888$77777777-7777-7777-7777-777777777777month ¤&*usd0
:ÀÈžÒ

plugin/wasmguest/caps/testdata/golden/subscriptions_list_tiers_resp.pb

@@ -0,0 +1,3 @@
+
+4
+$77777777-7777-7777-7777-777777777777Goldgold 

plugin/wasmguest/caps/testdata/golden/users_get_by_id_req.pb

@@ -0,0 +1,2 @@
+
+$11111111-1111-1111-1111-111111111111

plugin/wasmguest/caps/testdata/golden/users_get_by_id_resp.pb

@@ -0,0 +1,3 @@
+
+)
+$11111111-1111-1111-1111-111111111111
u

plugin/wasmguest/caps/testdata/golden/users_get_by_username_req.pb

@@ -0,0 +1,2 @@
+
+
u

plugin/wasmguest/caps/testdata/golden/users_get_by_username_resp.pb

@@ -0,0 +1,3 @@
+
+E
+$11111111-1111-1111-1111-111111111111u@x.com
u"
U*
a2
b8
Bmember

plugin/wasmguest/caps/users.go

@@ -0,0 +1,47 @@
+package caps
+
+import (
+	"context"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"git.dev.alexdunmow.com/block/core/auth"
+	"github.com/google/uuid"
+)
+
+// usersStub implements auth.PublicUsers over users.* capability calls.
+type usersStub struct{ base }
+
+var _ auth.PublicUsers = (*usersStub)(nil)
+
+func (s *usersStub) GetByUsername(ctx context.Context, username string) (*auth.PublicUserProfile, error) {
+	resp := &abiv1.UsersGetByUsernameResponse{}
+	req := &abiv1.UsersGetByUsernameRequest{Username: username}
+	if err := s.invoke(ctx, "get_by_username", req, resp); err != nil {
+		return nil, err
+	}
+	return publicUserFromProto(resp.GetUser()), nil
+}
+
+func (s *usersStub) GetByID(ctx context.Context, id uuid.UUID) (*auth.PublicUserProfile, error) {
+	resp := &abiv1.UsersGetByIdResponse{}
+	if err := s.invoke(ctx, "get_by_id", &abiv1.UsersGetByIdRequest{Id: id.String()}, resp); err != nil {
+		return nil, err
+	}
+	return publicUserFromProto(resp.GetUser()), nil
+}
+
+func publicUserFromProto(u *abiv1.PublicUserProfile) *auth.PublicUserProfile {
+	if u == nil {
+		return nil
+	}
+	return &auth.PublicUserProfile{
+		ID:            parseUUID(u.GetId()),
+		Email:         u.GetEmail(),
+		Username:      u.GetUsername(),
+		DisplayName:   u.GetDisplayName(),
+		AvatarURL:     u.GetAvatarUrl(),
+		Bio:           u.GetBio(),
+		EmailVerified: u.GetEmailVerified(),
+		Role:          u.GetRole(),
+	}
+}

plugin/wasmguest/caps/util.go

@@ -0,0 +1,34 @@
+package caps
+
+import (
+	"encoding/json"
+
+	"github.com/google/uuid"
+)
+
+// parseUUID parses a canonical UUID string, returning uuid.Nil for empty or
+// malformed input (host-side values are always canonical; this mirrors the
+// tolerant decode the render-context shim uses).
+func parseUUID(s string) uuid.UUID {
+	if s == "" {
+		return uuid.Nil
+	}
+	id, err := uuid.Parse(s)
+	if err != nil {
+		return uuid.Nil
+	}
+	return id
+}
+
+// unmarshalMap decodes a JSON object into map[string]any, returning nil for
+// empty or undecodable input (callers treat absent maps as nil).
+func unmarshalMap(raw []byte) map[string]any {
+	if len(raw) == 0 {
+		return nil
+	}
+	var m map[string]any
+	if err := json.Unmarshal(raw, &m); err != nil {
+		return nil
+	}
+	return m
+}

plugin/wasmguest/caps_wasmhost_test.go

@@ -0,0 +1,118 @@
+package wasmguest
+
+// End-to-end proof that the guest capability stubs (package caps, wired into
+// CoreServices by WO-WZ-003) marshal to the ABI, cross into a host over the
+// generic host_call import, and return decoded values the plugin's unchanged
+// service code consumes — all inside a real wazero-compiled wasm module.
+//
+// The host_call handler below is a throwaway fake capability table (like the
+// WO-WZ-002 throwaway host), not the cms host. It answers exactly the three
+// families the fixture's Load hook exercises.
+
+import (
+	"context"
+	"testing"
+
+	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
+	"github.com/tetratelabs/wazero"
+	"github.com/tetratelabs/wazero/api"
+	"google.golang.org/protobuf/proto"
+)
+
+// installBlockninjaHost instantiates the "blockninja" import module exporting
+// host_call, mirroring the guest calling convention in reverse (read a
+// HostCallRequest from guest memory, answer it, write a HostCallResponse back
+// via the guest's bn_alloc, return the packed pointer).
+func installBlockninjaHost(t *testing.T, ctx context.Context, r wazero.Runtime) {
+	t.Helper()
+	_, err := r.NewHostModuleBuilder("blockninja").
+		NewFunctionBuilder().
+		WithFunc(func(ctx context.Context, mod api.Module, ptr, size uint32) uint64 {
+			data, ok := mod.Memory().Read(ptr, size)
+			if !ok {
+				return 0
+			}
+			req := &abiv1.HostCallRequest{}
+			if err := proto.Unmarshal(data, req); err != nil {
+				return 0
+			}
+			out, err := proto.Marshal(fakeCapability(req.GetMethod(), req.GetPayload()))
+			if err != nil {
+				return 0
+			}
+			// Allocate the response in guest memory (bn_alloc may grow memory,
+			// so req is already decoded — data is no longer referenced).
+			res, err := mod.ExportedFunction("bn_alloc").Call(ctx, uint64(len(out)))
+			if err != nil || len(res) == 0 || res[0] == 0 {
+				return 0
+			}
+			respPtr := uint32(res[0])
+			if !mod.Memory().Write(respPtr, out) {
+				return 0
+			}
+			return uint64(respPtr)<<32 | uint64(uint32(len(out)))
+		}).
+		Export("host_call").
+		Instantiate(ctx)
+	if err != nil {
+		t.Fatalf("instantiate blockninja host module: %v", err)
+	}
+}
+
+// fakeCapability answers the three capability methods the fixture Load hook
+// calls; everything else is UNIMPLEMENTED.
+func fakeCapability(method string, payload []byte) *abiv1.HostCallResponse {
+	pack := func(m proto.Message) *abiv1.HostCallResponse {
+		b, err := proto.Marshal(m)
+		if err != nil {
+			return &abiv1.HostCallResponse{Error: &abiv1.AbiError{
+				Code: abiv1.AbiErrorCode_ABI_ERROR_CODE_INTERNAL, Message: err.Error(),
+			}}
+		}
+		return &abiv1.HostCallResponse{Payload: b}
+	}
+	switch method {
+	case "content.get_page":
+		return pack(&abiv1.ContentGetPageResponse{Page: &abiv1.PageInfo{Slug: "about", Title: "About Us"}})
+	case "settings.get_site_settings":
+		return pack(&abiv1.SettingsGetSiteSettingsResponse{SettingsJson: []byte(`{"site_name":"Fixture Site"}`)})
+	case "bridge.get_service":
+		return pack(&abiv1.BridgeGetServiceResponse{Available: false})
+	default:
+		return &abiv1.HostCallResponse{Error: &abiv1.AbiError{
+			Code: abiv1.AbiErrorCode_ABI_ERROR_CODE_UNIMPLEMENTED, Message: "no fake for " + method,
+		}}
+	}
+}
+
+// TestWasmFixtureCapabilityRoundTrip drives HOOK_LOAD (which calls the
+// capability stubs) then renders the report block that surfaces the results,
+// proving deps.Content / deps.Settings / deps.Bridge cross the ABI end-to-end.
+func TestWasmFixtureCapabilityRoundTrip(t *testing.T) {
+	if testing.Short() {
+		t.Skip("compiles a wasm module; skipped in -short")
+	}
+	w := instantiateFixture(t)
+
+	resp := w.invoke(t, abiv1.Hook_HOOK_LOAD, &abiv1.LoadRequest{})
+	if resp.GetError() != nil {
+		t.Fatalf("LOAD error: %v", resp.GetError())
+	}
+
+	resp = w.invoke(t, abiv1.Hook_HOOK_RENDER_BLOCK, &abiv1.RenderBlockRequest{
+		BlockKey:    "wasmfixture:greeting",
+		ContentJson: []byte(`{"report":true}`),
+	})
+	if resp.GetError() != nil {
+		t.Fatalf("RENDER_BLOCK error: %v", resp.GetError())
+	}
+	rb := &abiv1.RenderBlockResponse{}
+	if err := proto.Unmarshal(resp.GetPayload(), rb); err != nil {
+		t.Fatalf("unmarshal RenderBlockResponse: %v", err)
+	}
+	const want = "<p>capreport:page=About Us site=Fixture Site bridge_nil=true</p>"
+	if rb.GetHtml() != want {
+		t.Errorf("capability report html = %q, want %q", rb.GetHtml(), want)
+	}
+	t.Logf("capability round trip through wasm: %s", rb.GetHtml())
+}

plugin/wasmguest/describe.go

@@ -8,8 +8,8 @@ import (
 
 	"connectrpc.com/connect"
 	abiv1 "git.dev.alexdunmow.com/block/core/abi/v1"
-	"git.dev.alexdunmow.com/block/core/ai"
 	"git.dev.alexdunmow.com/block/core/plugin"
+	"git.dev.alexdunmow.com/block/core/plugin/wasmguest/caps"
 	"git.dev.alexdunmow.com/block/core/rbac"
 	"github.com/google/uuid"
 	"google.golang.org/protobuf/proto"
@@ -197,14 +197,14 @@ func (g *guest) captureRagFetcherTypes() (types []string) {
 	if g.reg.Load == nil {
 		return nil
 	}
-	rag := &guestRAGService{fetchers: make(map[string]plugin.ContentFetcher)}
+	rag := caps.NewRAGStub(nil)
 	svcs := describeServices()
 	svcs.RAGService = rag
 	func() {
 		defer func() { recover() }() //nolint:errcheck // publish-time probe
 		_ = g.reg.Load(svcs)
 	}()
-	return sortedKeys(rag.fetchers)
+	return rag.FetcherTypes()
 }
 
 // captureServiceRegistration probes ServiceHandlers to record RBAC method
@@ -247,14 +247,14 @@ func (g *guest) captureServiceRegistration(m *abiv1.PluginManifest) {
 	}
 }
 
-// describeServices returns the CoreServices value used to probe
+// describeServices returns the CoreServices value used to probe registration
-// registration funcs at publish time: only side-effect-free capture stubs
+// funcs at publish time. It uses the capability stubs with a nil transport:
-// are populated. Anything else a plugin touches during the probe panics and
+// there is no live host during DESCRIBE, so any capability a plugin invokes
-// is recovered by the caller.
+// returns a clean "no host transport" error instead of nil-panicking, letting
+// the probe capture whatever static registrations (jobs, RAG fetchers)
+// surround the call. Callers still recover, belt-and-suspenders.
 func describeServices() plugin.CoreServices {
-	return plugin.CoreServices{
+	return caps.NewCoreServices(nil)
-		ToolRegistry: noopToolRegistry{},
-	}
 }
 
 func masterPageToProto(mp plugin.MasterPageDefinition) *abiv1.MasterPageDefinition {
@@ -299,10 +299,6 @@ func (c *captureCoreServiceBindings) Bind(serviceName string, methodRoles map[st
 		}, methodRoles), nil
 }
 
-type noopToolRegistry struct{}
-
-func (noopToolRegistry) Register(*ai.ToolDefinition) {}
-
 // noopProvisioner satisfies plugin.Provisioner for the DESCRIBE-time
 // Register pass; real provisioning runs host-side at load.
 type noopProvisioner struct{}