diff --git a/backend/src/workspaces/annotations.ts b/backend/src/workspaces/annotations.ts
new file mode 100644
index 00000000..60d2376d
--- /dev/null
+++ b/backend/src/workspaces/annotations.ts
@@ -0,0 +1,28 @@
+import { parseAllDocuments } from "yaml";
+import { WorkspaceRegistryError } from "./git-repository.js";
+
+/**
+ * Coarse structural validation for a curated annotation blob at activation time. The harness
+ * Pydantic parser remains the authority for per-table shapes; this check rejects only YAML that
+ * cannot possibly be a canonical `Annotations` document (single mapping, optional `tables` mapping).
+ */
+export function parseAnnotationsYaml(source: string): void {
+  try {
+    const documents = parseAllDocuments(source, { uniqueKeys: true });
+    if (documents.length !== 1) throw new Error("malformed annotations");
+    const document = documents[0];
+    if (document.errors.length > 0 || document.warnings.length > 0) throw new Error("malformed annotations");
+    const parsed = document.toJSON();
+    if (parsed === null || parsed === undefined) return; // empty canonical set
+    if (typeof parsed !== "object" || Array.isArray(parsed)) throw new Error("malformed annotations");
+    const record = parsed as Record<string, unknown>;
+    if (
+      record.tables !== undefined
+      && (typeof record.tables !== "object" || record.tables === null || Array.isArray(record.tables))
+    ) {
+      throw new Error("malformed annotations");
+    }
+  } catch {
+    throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations are malformed");
+  }
+}
diff --git a/backend/src/workspaces/git-repository.ts b/backend/src/workspaces/git-repository.ts
index f2ef6abb..bb85a43f 100644
--- a/backend/src/workspaces/git-repository.ts
+++ b/backend/src/workspaces/git-repository.ts
@@ -2,7 +2,7 @@ import { execFile, spawn, type ChildProcessWithoutNullStreams } from "node:child
 import { lstatSync, mkdirSync } from "node:fs";
 import { mkdir, rm, writeFile } from "node:fs/promises";
 import { basename, dirname, isAbsolute, join } from "node:path";
-import { promisify } from "node:util";
+import { promisify, TextDecoder } from "node:util";
 import type { WorkspaceErrorCode, WorkspaceRegistryConfig } from "./types.js";
 
 const execFileAsync = promisify(execFile);
@@ -39,6 +39,15 @@ function assertDirectory(path: string): void {
   }
 }
 
+function isValidUtf8(buffer: Buffer): boolean {
+  try {
+    new TextDecoder("utf-8", { fatal: true }).decode(buffer);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
 function gitErrorCode(error: unknown): WorkspaceErrorCode {
   const detail = [
     error instanceof Error ? error.message : "",
@@ -233,6 +242,66 @@ export class GitWorkspaceRepository {
     }
   }
 
+  /** Read the curated FK annotations object at an exact commit, or undefined when absent. */
+  async annotationsObject(revision: string, id: string): Promise<{ blobId: string; contents: Buffer } | undefined> {
+    if (!/^[0-9a-f]{40}$/.test(revision)) {
+      throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations revision is invalid");
+    }
+    if (!/^[a-z][a-z0-9-]{2,62}$/.test(id) || id === "workspace-docs") {
+      throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations path is invalid");
+    }
+    const path = `${id}/schema/annotations.yaml`;
+    // ls-tree -z reports the exact object at the path (or its children when the path is a tree).
+    const listing = await this.git(["ls-tree", "-z", "--full-tree", revision, "--", path]);
+    const entries = listing.split("\0").filter((entry) => entry.length > 0);
+    if (entries.length === 0) return undefined;
+    const exact = entries.find((entry) => entry.slice(entry.lastIndexOf("\t") + 1) === path);
+    if (exact === undefined) {
+      // The path resolves to a tree (its children are listed) or another non-blob object.
+      throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations object is invalid");
+    }
+    const match = /^([0-9]{6})\s+(blob|tree|commit)\s+([0-9a-f]{40})\t/.exec(exact);
+    // Only regular Git blobs are accepted: symlinks (120000) and gitlinks (160000) are refused.
+    if (match === null || match[2] !== "blob" || (match[1] !== "100644" && match[1] !== "100755")) {
+      throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations object is invalid");
+    }
+    const blobId = match[3];
+    const contents = await this.gitBlobBuffer(blobId, 16 * 1024 * 1024);
+    if (!isValidUtf8(contents)) {
+      throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations object is not valid UTF-8");
+    }
+    return { blobId, contents };
+  }
+
+  private async gitBlobBuffer(objectId: string, maxBytes: number): Promise<Buffer> {
+    if (!/^[0-9a-f]{40}$/.test(objectId)) {
+      throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations object is invalid");
+    }
+    try {
+      const { stdout } = await execFileAsync(
+        "git",
+        ["-c", `core.hooksPath=${this.hooksPath}`, "cat-file", "blob", objectId],
+        {
+          cwd: this.repoPath,
+          env: { ...process.env, GIT_TERMINAL_PROMPT: "0" },
+          encoding: "buffer",
+          maxBuffer: maxBytes + 1024 * 1024,
+        },
+      );
+      if (stdout.length > maxBytes) {
+        throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations object is too large");
+      }
+      return stdout;
+    } catch (error) {
+      if (error instanceof WorkspaceRegistryError) throw error;
+      const detail = error instanceof Error ? error.message : "";
+      if (/maxBuffer|stdout maxBuffer/i.test(detail)) {
+        throw new WorkspaceRegistryError("workspace_invalid", "Workspace annotations object is too large");
+      }
+      throw this.sanitizeGitError(error);
+    }
+  }
+
   /** Write only a validated API-owned artifact below the checked-out repository. */
   async writeRegistryFile(path: string, source: string): Promise<void> {
     this.assertRegistryArtifactPath(path);
diff --git a/backend/src/workspaces/registry.ts b/backend/src/workspaces/registry.ts
index 49950419..2f05e04a 100644
--- a/backend/src/workspaces/registry.ts
+++ b/backend/src/workspaces/registry.ts
@@ -3,6 +3,7 @@ import { lstatSync } from "node:fs";
 import { mkdir, readdir, readFile, rename, rm, writeFile } from "node:fs/promises";
 import { isAbsolute, join } from "node:path";
 import { buildInstallationContract, renderWorkspaceDocs } from "./contracts.js";
+import { parseAnnotationsYaml } from "./annotations.js";
 import { assertCatalogMatchesDescriptor, parseWorkspaceCatalogYaml, type WorkspaceCatalog, type WorkspaceCatalogEntry } from "./catalog.js";
 import {
   GitWorkspaceRepository,
@@ -581,6 +582,10 @@ export class WorkspaceRegistry {
         }
         assertCatalogMatchesDescriptor(entry, workspace);
         await this.assertEvidenceContext(workspace, safeHead);
+        const annotations = await this.repository.annotationsObject(safeHead, id);
+        if (annotations !== undefined) {
+          parseAnnotationsYaml(annotations.contents.toString("utf8"));
+        }
         const collection = workspace.semantic_index.vector_store.collection;
         const owner = collectionOwners.get(collection);
         if (owner !== undefined) {
diff --git a/backend/test/registry-annotations.test.ts b/backend/test/registry-annotations.test.ts
new file mode 100644
index 00000000..1f612b64
--- /dev/null
+++ b/backend/test/registry-annotations.test.ts
@@ -0,0 +1,116 @@
+import { execFile } from "node:child_process";
+import { mkdtempSync, mkdirSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { promisify } from "node:util";
+import { afterEach, expect, test } from "vitest";
+import { WorkspaceRegistry } from "../src/workspaces/registry.js";
+import type { WorkspaceRegistryConfig } from "../src/workspaces/types.js";
+
+const runFile = promisify(execFile);
+const temporaryRoots: string[] = [];
+
+afterEach(() => {
+  temporaryRoots.splice(0).forEach((root) => rmSync(root, { recursive: true, force: true }));
+});
+
+const validYaml = `workspace:
+  schema_version: 3
+  id: psd-clinical
+  name: Policlinico San Donato
+  language: it
+dwh:
+  engine: postgres
+  database: postgres
+  schema: datawarehouse
+  supported_transports: [postgres_direct]
+semantic_index:
+  vector_store:
+    engine: qdrant
+    collection: psd-clinical
+    dimensions: 1024
+    distance: cosine
+  embedding:
+    provider: ollama_internal
+    model: qwen3-embedding:0.6b
+    dimensions: 1024
+llm_policy:
+  allowed: [zai/glm-5.2]
+`;
+
+async function git(cwd: string, args: string[]): Promise<string> {
+  const { stdout } = await runFile("git", args, { cwd });
+  return stdout.trim();
+}
+
+function config(root: string, remoteUrl: string): WorkspaceRegistryConfig {
+  return {
+    root,
+    remoteUrl,
+    branch: "main",
+    gitAuthorName: "Registry Annotations Test",
+    gitAuthorEmail: "registry-annotations@example.invalid",
+    installationId: "test",
+    secretRoots: [],
+    maxImportBytes: 1024,
+    maxImportEntries: 1,
+  };
+}
+
+type AnnotationsLayout = "absent" | "valid" | "malformed" | "dir";
+
+async function fixture(layout: AnnotationsLayout): Promise<{ root: string; remote: string }> {
+  const root = mkdtempSync(join(tmpdir(), "thoth-registry-annotations-"));
+  temporaryRoots.push(root);
+  const remote = join(root, "remote.git");
+  const source = join(root, "source");
+  await git(root, ["init", "--bare", "--initial-branch=main", remote]);
+  mkdirSync(source);
+  await git(source, ["init", "--initial-branch=main"]);
+  await git(source, ["config", "user.name", "Registry Annotations Test"]);
+  await git(source, ["config", "user.email", "registry-annotations@example.invalid"]);
+  writeFileSync(join(source, "thoth-workspaces.yaml"),
+    "schema_version: 1\nworkspaces:\n  - id: psd-clinical\n    name: Policlinico San Donato\n");
+  mkdirSync(join(source, "psd-clinical", "schema"), { recursive: true });
+  writeFileSync(join(source, "psd-clinical", "workspace.yaml"), validYaml);
+  const annotationsPath = join(source, "psd-clinical", "schema", "annotations.yaml");
+  if (layout === "valid") writeFileSync(annotationsPath, "tables: {}\n");
+  if (layout === "malformed") writeFileSync(annotationsPath, "tables: [not, a, mapping]\n");
+  if (layout === "dir") {
+    mkdirSync(annotationsPath, { recursive: true });
+    writeFileSync(join(annotationsPath, "child.txt"), "nested\n");
+  }
+  await git(source, ["add", "-A"]);
+  await git(source, ["commit", "-m", "initial"]);
+  await git(source, ["remote", "add", "origin", remote]);
+  await git(source, ["push", "origin", "main"]);
+  return { root, remote };
+}
+
+test("activation accepts a valid curated annotation blob", async () => {
+  const fixtureValue = await fixture("valid");
+  const registry = new WorkspaceRegistry(config(join(fixtureValue.root, "registry"), fixtureValue.remote));
+
+  await expect(registry.bootstrap()).resolves.toMatchObject({ degraded: false });
+});
+
+test("activation accepts an absent annotation blob", async () => {
+  const fixtureValue = await fixture("absent");
+  const registry = new WorkspaceRegistry(config(join(fixtureValue.root, "registry"), fixtureValue.remote));
+
+  await expect(registry.bootstrap()).resolves.toMatchObject({ degraded: false });
+});
+
+test("activation rejects malformed annotations", async () => {
+  const fixtureValue = await fixture("malformed");
+  const registry = new WorkspaceRegistry(config(join(fixtureValue.root, "registry"), fixtureValue.remote));
+
+  await expect(registry.bootstrap()).rejects.toMatchObject({ code: "workspace_invalid" });
+});
+
+test("activation rejects a tree at the annotations path", async () => {
+  const fixtureValue = await fixture("dir");
+  const registry = new WorkspaceRegistry(config(join(fixtureValue.root, "registry"), fixtureValue.remote));
+
+  await expect(registry.bootstrap()).rejects.toMatchObject({ code: "workspace_invalid" });
+});
diff --git a/backend/test/workspaces-git-annotations.test.ts b/backend/test/workspaces-git-annotations.test.ts
new file mode 100644
index 00000000..82957e4e
--- /dev/null
+++ b/backend/test/workspaces-git-annotations.test.ts
@@ -0,0 +1,150 @@
+import { execFile } from "node:child_process";
+import { mkdtempSync, mkdirSync, rmSync, symlinkSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { promisify } from "node:util";
+import { afterEach, expect, test } from "vitest";
+import { GitWorkspaceRepository } from "../src/workspaces/git-repository.js";
+import type { WorkspaceRegistryConfig } from "../src/workspaces/types.js";
+
+const runFile = promisify(execFile);
+const temporaryRoots: string[] = [];
+
+afterEach(() => {
+  temporaryRoots.splice(0).forEach((root) => rmSync(root, { recursive: true, force: true }));
+});
+
+async function git(cwd: string, args: string[]): Promise<string> {
+  const { stdout } = await runFile("git", args, { cwd });
+  return stdout.trim();
+}
+
+function config(root: string, remoteUrl: string): WorkspaceRegistryConfig {
+  return {
+    root,
+    remoteUrl,
+    branch: "main",
+    gitAuthorName: "Workspace Registry Test",
+    gitAuthorEmail: "workspace-registry@example.invalid",
+    installationId: "test",
+    secretRoots: [],
+    maxImportBytes: 1024,
+    maxImportEntries: 1,
+  };
+}
+
+interface RepoFixture {
+  root: string;
+  remote: string;
+  source: string;
+  commit: string;
+}
+
+async function makeRepo(id: string, annotations: string | Buffer | "dir" | "symlink"): Promise<RepoFixture> {
+  const root = mkdtempSync(join(tmpdir(), "thoth-annotations-git-"));
+  temporaryRoots.push(root);
+  const remote = join(root, "remote.git");
+  const source = join(root, "source");
+  await git(root, ["init", "--bare", "--initial-branch=main", remote]);
+  mkdirSync(source);
+  await git(source, ["init", "--initial-branch=main"]);
+  await git(source, ["config", "user.name", "Annotations Test"]);
+  await git(source, ["config", "user.email", "annotations@example.invalid"]);
+  writeFileSync(join(source, "thoth-workspaces.yaml"),
+    `schema_version: 1\nworkspaces: [{id: ${id}, name: Workspace}]\n`);
+  mkdirSync(join(source, id, "schema"), { recursive: true });
+  writeFileSync(join(source, id, "workspace.yaml"), `workspace:\n  schema_version: 3\n  id: ${id}\n`);
+  const annotationsPath = join(source, id, "schema", "annotations.yaml");
+  if (annotations === "dir") {
+    mkdirSync(annotationsPath, { recursive: true });
+    writeFileSync(join(annotationsPath, "child.txt"), "not a blob\n");
+  } else if (annotations === "symlink") {
+    writeFileSync(join(source, id, "target.yaml"), "tables: {}\n");
+    symlinkSync("target.yaml", annotationsPath);
+  } else {
+    writeFileSync(annotationsPath, annotations);
+  }
+  await git(source, ["add", "-A"]);
+  await git(source, ["commit", "-m", "initial"]);
+  await git(source, ["remote", "add", "origin", remote]);
+  await git(source, ["push", "origin", "main"]);
+  const commit = await git(source, ["rev-parse", "HEAD"]);
+  return { root, remote, source, commit };
+}
+
+async function bootstrapped(fixture: RepoFixture): Promise<GitWorkspaceRepository> {
+  const repository = new GitWorkspaceRepository(config(join(fixture.root, "registry"), fixture.remote));
+  await repository.bootstrap();
+  return repository;
+}
+
+test("reads a regular annotation blob at the exact commit", async () => {
+  const fixture = await makeRepo("research", "tables: {}\n");
+  const repository = await bootstrapped(fixture);
+
+  const object = await repository.annotationsObject(fixture.commit, "research");
+
+  expect(object).toBeDefined();
+  expect(object!.blobId).toMatch(/^[0-9a-f]{40}$/);
+  expect(object!.contents.toString("utf8")).toBe("tables: {}\n");
+});
+
+test("returns undefined when the annotation object is absent", async () => {
+  const fixture = await makeRepo("research", "tables: {}\n");
+  const repository = await bootstrapped(fixture);
+
+  await expect(repository.annotationsObject(fixture.commit, "absent")).resolves.toBeUndefined();
+});
+
+test("refuses a tree at the annotation path", async () => {
+  const fixture = await makeRepo("clinical", "dir");
+  const repository = await bootstrapped(fixture);
+
+  await expect(repository.annotationsObject(fixture.commit, "clinical"))
+    .rejects.toMatchObject({ code: "workspace_invalid" });
+});
+
+test("refuses a symlink at the annotation path", async () => {
+  const fixture = await makeRepo("research", "symlink");
+  const repository = await bootstrapped(fixture);
+
+  await expect(repository.annotationsObject(fixture.commit, "research"))
+    .rejects.toMatchObject({ code: "workspace_invalid" });
+});
+
+test("refuses oversized and non-UTF-8 annotation blobs", async () => {
+  const oversized = await makeRepo("research", Buffer.concat([
+    Buffer.from("tables: {}\n"),
+    Buffer.alloc(16 * 1024 * 1024, 0x78),
+  ]));
+  const repository = await bootstrapped(oversized);
+  await expect(repository.annotationsObject(oversized.commit, "research"))
+    .rejects.toMatchObject({ code: "workspace_invalid" });
+
+  const nonUtf8 = await makeRepo("research", Buffer.from([0x74, 0x61, 0x62, 0xff, 0xfe, 0x00]));
+  const repository2 = await bootstrapped(nonUtf8);
+  await expect(repository2.annotationsObject(nonUtf8.commit, "research"))
+    .rejects.toMatchObject({ code: "workspace_invalid" });
+});
+
+test("refuses malformed ids and revisions before Git", async () => {
+  const fixture = await makeRepo("research", "tables: {}\n");
+  const repository = await bootstrapped(fixture);
+
+  await expect(repository.annotationsObject(fixture.commit, "workspace-docs"))
+    .rejects.toMatchObject({ code: "workspace_invalid" });
+  await expect(repository.annotationsObject(fixture.commit, "../research"))
+    .rejects.toMatchObject({ code: "workspace_invalid" });
+  await expect(repository.annotationsObject("HEAD", "research"))
+    .rejects.toMatchObject({ code: "workspace_invalid" });
+});
+
+test("redacts Git failures while reading the annotation blob", async () => {
+  const fixture = await makeRepo("research", "tables: {}\n");
+  const repository = await bootstrapped(fixture);
+  rmSync(repository.repoPath, { recursive: true, force: true });
+
+  const error = await repository.annotationsObject(fixture.commit, "research").catch((failure: unknown) => failure);
+  expect(error).toMatchObject({ code: "git_unavailable", message: "Workspace Git operation failed" });
+  expect((error as Error).message).not.toContain(fixture.root);
+});