diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..60d3900
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,50 @@
+SDK_MODULE := git.dev.alexdunmow.com/block/core
+SDK_VERSION ?= $(shell git describe --tags --abbrev=0)
+
+SDK_DOWNSTREAM_DIRS := \
+	$(HOME)/src/blockninja/backend \
+	$(HOME)/src/assumechaos \
+	$(HOME)/src/bidbuddy \
+	$(HOME)/src/bidmasters \
+	$(HOME)/src/coterieos \
+	$(HOME)/src/messenger \
+	$(HOME)/src/perthplaygrounds \
+	$(HOME)/src/symposium
+
+.PHONY: update-sdk
+update-sdk:
+	@set -e; \
+	for dir in $(SDK_DOWNSTREAM_DIRS); do \
+		if [ ! -f "$$dir/go.mod" ]; then \
+			echo "skip $$dir (no go.mod)"; \
+			continue; \
+		fi; \
+		echo "==> $$dir: $(SDK_MODULE)@$(SDK_VERSION)"; \
+		( \
+			cd "$$dir"; \
+			go mod edit -dropreplace=$(SDK_MODULE) 2>/dev/null || true; \
+			go get $(SDK_MODULE)@$(SDK_VERSION); \
+			go mod tidy; \
+			if grep -q '^replace $(SDK_MODULE)' go.mod; then \
+				echo "replace directive still present in $$dir/go.mod" >&2; \
+				exit 1; \
+			fi; \
+		); \
+	done
+
+.PHONY: check-sdk-pins
+check-sdk-pins:
+	@set -e; \
+	for dir in $(SDK_DOWNSTREAM_DIRS); do \
+		if [ ! -f "$$dir/go.mod" ]; then \
+			continue; \
+		fi; \
+		if grep -q '^replace $(SDK_MODULE)' "$$dir/go.mod"; then \
+			echo "replace directive found in $$dir/go.mod" >&2; \
+			exit 1; \
+		fi; \
+		if ! grep -Eq '^[[:space:]]*$(SDK_MODULE)[[:space:]]+v[0-9]+\.[0-9]+\.[0-9]+' "$$dir/go.mod"; then \
+			echo "$(SDK_MODULE) is not pinned in $$dir/go.mod" >&2; \
+			exit 1; \
+		fi; \
+	done
diff --git a/blocks/registry.go b/blocks/registry.go
index c70e1b1..cd1e3ef 100644
--- a/blocks/registry.go
+++ b/blocks/registry.go
@@ -6,5 +6,7 @@ import "io/fs"
 type BlockRegistry interface {
 	Register(meta BlockMeta, fn BlockFunc)
 	RegisterTemplateOverride(templateKey, blockKey string, fn BlockFunc)
+	RegisterTemplateOverrideWithSource(templateKey, blockKey, source string, fn BlockFunc)
 	LoadSchemasFromFS(fsys fs.FS) error
+	LoadSchemasFromFSWithPrefix(fsys fs.FS, prefix string) error
 }
diff --git a/content/content.go b/content/content.go
index b67ae95..5c6b472 100644
--- a/content/content.go
+++ b/content/content.go
@@ -41,7 +41,7 @@ type Content interface {
 	GetPage(ctx context.Context, slug string) (*PageInfo, error)
 	GetPost(ctx context.Context, slug string) (*PostInfo, error)
 	Slugify(text string) string
-	BlockNoteToHTML(doc map[string]any) string
+	BlockNoteToHTML(ctx context.Context, doc map[string]any) string
 	GenerateExcerpt(html string, maxLen int) string
 	StripHTML(s string) string
 }
diff --git a/plugin/block_registry.go b/plugin/block_registry.go
index 5ee5d07..b461861 100644
--- a/plugin/block_registry.go
+++ b/plugin/block_registry.go
@@ -2,6 +2,7 @@ package plugin
 
 import (
 	"io/fs"
+	"strings"
 
 	"git.dev.alexdunmow.com/block/core/blocks"
 )
@@ -18,15 +19,25 @@ func NewPluginBlockRegistry(inner blocks.BlockRegistry, pluginName string) *Plug
 }
 
 func (r *PluginBlockRegistry) Register(meta blocks.BlockMeta, fn blocks.BlockFunc) {
-	meta.Key = r.prefix + ":" + meta.Key
+	if !strings.Contains(meta.Key, ":") {
+		meta.Key = r.prefix + ":" + meta.Key
+	}
 	meta.Source = r.prefix
 	r.inner.Register(meta, fn)
 }
 
 func (r *PluginBlockRegistry) RegisterTemplateOverride(templateKey, blockKey string, fn blocks.BlockFunc) {
-	r.inner.RegisterTemplateOverride(templateKey, blockKey, fn)
+	r.inner.RegisterTemplateOverrideWithSource(templateKey, blockKey, r.prefix, fn)
+}
+
+func (r *PluginBlockRegistry) RegisterTemplateOverrideWithSource(templateKey, blockKey, source string, fn blocks.BlockFunc) {
+	r.inner.RegisterTemplateOverrideWithSource(templateKey, blockKey, source, fn)
 }
 
 func (r *PluginBlockRegistry) LoadSchemasFromFS(fsys fs.FS) error {
-	return r.inner.LoadSchemasFromFS(fsys)
+	return r.inner.LoadSchemasFromFSWithPrefix(fsys, r.prefix)
+}
+
+func (r *PluginBlockRegistry) LoadSchemasFromFSWithPrefix(fsys fs.FS, prefix string) error {
+	return r.inner.LoadSchemasFromFSWithPrefix(fsys, prefix)
 }
diff --git a/plugin/block_registry_test.go b/plugin/block_registry_test.go
new file mode 100644
index 0000000..e004673
--- /dev/null
+++ b/plugin/block_registry_test.go
@@ -0,0 +1,70 @@
+package plugin
+
+import (
+	"io/fs"
+	"testing"
+
+	"git.dev.alexdunmow.com/block/core/blocks"
+)
+
+type recordingBlockRegistry struct {
+	registeredKey    string
+	registeredSource string
+	overrideSource   string
+	schemaPrefix     string
+}
+
+func (r *recordingBlockRegistry) Register(meta blocks.BlockMeta, _ blocks.BlockFunc) {
+	r.registeredKey = meta.Key
+	r.registeredSource = meta.Source
+}
+
+func (r *recordingBlockRegistry) RegisterTemplateOverride(_, _ string, _ blocks.BlockFunc) {}
+
+func (r *recordingBlockRegistry) RegisterTemplateOverrideWithSource(_, _, source string, _ blocks.BlockFunc) {
+	r.overrideSource = source
+}
+
+func (r *recordingBlockRegistry) LoadSchemasFromFS(fsys fs.FS) error {
+	return r.LoadSchemasFromFSWithPrefix(fsys, "")
+}
+
+func (r *recordingBlockRegistry) LoadSchemasFromFSWithPrefix(_ fs.FS, prefix string) error {
+	r.schemaPrefix = prefix
+	return nil
+}
+
+func TestPluginBlockRegistryPrefixesOnlyUnqualifiedKeys(t *testing.T) {
+	inner := &recordingBlockRegistry{}
+	registry := NewPluginBlockRegistry(inner, "course")
+
+	registry.Register(blocks.BlockMeta{Key: "lesson"}, nil)
+	if inner.registeredKey != "course:lesson" {
+		t.Fatalf("Register() key = %q, want course:lesson", inner.registeredKey)
+	}
+	if inner.registeredSource != "course" {
+		t.Fatalf("Register() source = %q, want course", inner.registeredSource)
+	}
+
+	registry.Register(blocks.BlockMeta{Key: "course:lesson"}, nil)
+	if inner.registeredKey != "course:lesson" {
+		t.Fatalf("Register() double-prefixed qualified key: %q", inner.registeredKey)
+	}
+}
+
+func TestPluginBlockRegistryTracksOverrideAndSchemaSource(t *testing.T) {
+	inner := &recordingBlockRegistry{}
+	registry := NewPluginBlockRegistry(inner, "course")
+
+	registry.RegisterTemplateOverride("shared-theme", "lesson", nil)
+	if inner.overrideSource != "course" {
+		t.Fatalf("override source = %q, want course", inner.overrideSource)
+	}
+
+	if err := registry.LoadSchemasFromFS(nil); err != nil {
+		t.Fatalf("LoadSchemasFromFS() error = %v", err)
+	}
+	if inner.schemaPrefix != "course" {
+		t.Fatalf("schema prefix = %q, want course", inner.schemaPrefix)
+	}
+}
diff --git a/render/blocknote.go b/render/blocknote.go
index 5e6df56..1828da3 100644
--- a/render/blocknote.go
+++ b/render/blocknote.go
@@ -1,22 +1,26 @@
 package render
 
 import (
+	"context"
 	"encoding/json"
 	"fmt"
 	"html"
 	"strings"
+
+	"git.dev.alexdunmow.com/block/core/blocks"
+	"github.com/google/uuid"
 )
 
 // BlockNoteToHTML converts a BlockNote document (map with "blocks" key) to HTML.
-func BlockNoteToHTML(doc map[string]any) string {
+func BlockNoteToHTML(ctx context.Context, doc map[string]any) string {
 	blocks := blocksFromRaw(doc["blocks"])
 	if len(blocks) == 0 {
 		return ""
 	}
-	return renderBlocks(blocks)
+	return renderBlocks(ctx, blocks)
 }
 
-func renderBlocks(blocks []map[string]any) string {
+func renderBlocks(ctx context.Context, blocks []map[string]any) string {
 	var sb strings.Builder
 	var currentListType string
 	var listItems []map[string]any
@@ -34,7 +38,7 @@ func renderBlocks(blocks []map[string]any) string {
 		fmt.Fprintf(&sb, "<%s class=\"my-4 pl-6 space-y-2 %s\">\n", tag, listStyle)
 		for _, item := range listItems {
 			content := inlineContentFromRaw(item["content"])
-			childrenHTML := renderChildren(item["children"])
+			childrenHTML := renderChildren(ctx, item["children"])
 			sb.WriteString("<li>")
 			sb.WriteString(renderInlineContent(content))
 			if childrenHTML != "" {
@@ -60,7 +64,7 @@ func renderBlocks(blocks []map[string]any) string {
 		}
 
 		flushList()
-		sb.WriteString(renderBlock(blockMap))
+		sb.WriteString(renderBlock(ctx, blockMap))
 	}
 
 	flushList()
@@ -106,11 +110,11 @@ func blocksFromRaw(raw any) []map[string]any {
 	}
 }
 
-func renderBlock(block map[string]any) string {
+func renderBlock(ctx context.Context, block map[string]any) string {
 	blockType, _ := block["type"].(string)
 	props, _ := block["props"].(map[string]any)
 	content := inlineContentFromRaw(block["content"])
-	childrenHTML := renderChildren(block["children"])
+	childrenHTML := renderChildren(ctx, block["children"])
 
 	var sb strings.Builder
 
@@ -220,6 +224,33 @@ func renderBlock(block map[string]any) string {
 		}
 		sb.WriteString("</table></div>\n")
 
+	case "embed":
+		if resolver := blocks.GetEmbedResolver(ctx); resolver != nil {
+			blockID := ""
+			if v, ok := props["blockId"].(string); ok {
+				blockID = v
+			}
+			dataSource := ""
+			if v, ok := props["dataSource"].(string); ok {
+				dataSource = v
+			}
+			layout := "full"
+			if v, ok := props["layout"].(string); ok && v != "" {
+				layout = v
+			}
+			if blockID != "" {
+				if parsedID, err := uuid.Parse(blockID); err == nil {
+					sb.WriteString(resolver.RenderEmbed(ctx, parsedID, dataSource, layout))
+				}
+			}
+		}
+
+	case "humanProof":
+		if hp := blocks.GetHumanProofBanner(ctx); hp != nil {
+			sb.WriteString(blocks.RenderHumanProofBanner(hp))
+			sb.WriteByte('\n')
+		}
+
 	case "references":
 		sb.WriteString("<div class=\"bn-references\">\n")
 		sb.WriteString("<div class=\"bn-references-label\">References</div>\n")
@@ -257,12 +288,12 @@ func renderBlock(block map[string]any) string {
 	return sb.String()
 }
 
-func renderChildren(children any) string {
+func renderChildren(ctx context.Context, children any) string {
 	blocks := blocksFromRaw(children)
 	if len(blocks) == 0 {
 		return ""
 	}
-	return renderBlocks(blocks)
+	return renderBlocks(ctx, blocks)
 }
 
 func renderInlineContent(content []map[string]any) string {
diff --git a/render/blocknote_test.go b/render/blocknote_test.go
new file mode 100644
index 0000000..5ffdf29
--- /dev/null
+++ b/render/blocknote_test.go
@@ -0,0 +1,48 @@
+package render
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"git.dev.alexdunmow.com/block/core/blocks"
+	"github.com/google/uuid"
+)
+
+type testEmbedResolver struct{}
+
+func (testEmbedResolver) RenderEmbed(_ context.Context, blockID uuid.UUID, dataSource, layout string) string {
+	return "embed:" + blockID.String() + ":" + dataSource + ":" + layout
+}
+
+func TestBlockNoteToHTMLUsesSDKContextResolvers(t *testing.T) {
+	blockID := uuid.MustParse("11111111-1111-1111-1111-111111111111")
+	ctx := blocks.WithEmbedResolver(context.Background(), testEmbedResolver{})
+	ctx = blocks.WithHumanProofBanner(ctx, &blocks.HumanProofBannerData{
+		ActiveTimeMinutes: 12,
+		KeystrokeCount:    3456,
+		SessionCount:      2,
+		PostSlug:          "proof-post",
+	})
+
+	html := BlockNoteToHTML(ctx, map[string]any{
+		"blocks": []any{
+			map[string]any{
+				"type": "embed",
+				"props": map[string]any{
+					"blockId":    blockID.String(),
+					"dataSource": "row:22222222-2222-2222-2222-222222222222",
+					"layout":     "card",
+				},
+			},
+			map[string]any{"type": "humanProof"},
+		},
+	})
+
+	if !strings.Contains(html, "embed:"+blockID.String()+":row:22222222-2222-2222-2222-222222222222:card") {
+		t.Fatalf("BlockNoteToHTML() did not render embed from SDK context: %s", html)
+	}
+	if !strings.Contains(html, `data-human-proof-banner`) || !strings.Contains(html, `proof-post`) {
+		t.Fatalf("BlockNoteToHTML() did not render human proof banner from SDK context: %s", html)
+	}
+}