diff --git a/packages/agentstack/PRD.md b/packages/agentstack/PRD.md
index e514ac2..b18e861 100644
--- a/packages/agentstack/PRD.md
+++ b/packages/agentstack/PRD.md
@@ -74,7 +74,8 @@ Backed by `src/index.ts`, `src/types.ts`, `src/manifest.ts`:
 - **Status lifecycle** — `pending → queued → running → blocked → complete | failed | cancelled`.
 - **`AgentStack` coordinator** (in-memory `Map` storage, injectable clock):
   `registerAgent`, `getAgent`, `createTask`, `getTask`, `assignTask`, `updateTaskStatus`,
-  `delegate`, `revokeDelegation`, `listTasks`, `snapshot`, and an `on(listener)` event subscription.
+  `delegate`, `revokeDelegation`, `listDelegations`, `hasDelegation`, `listTasks`, `snapshot`,
+  and an `on(listener)` event subscription.
 - **Events** — `agent.registered`, `task.created`, `task.assigned`, `task.updated`,
   `delegation.granted`, `delegation.revoked`.
 - **`agentStackPlugin`** — a LogicSRC `PluginDefinition`, plus `agentStackManifest` declaring
diff --git a/packages/agentstack/README.md b/packages/agentstack/README.md
index 131f12e..8cceff9 100644
--- a/packages/agentstack/README.md
+++ b/packages/agentstack/README.md
@@ -15,7 +15,8 @@ Shared AppKit OpenSpec (`profullstack-web/openspec/specs/agentstack`).
   (`pending → queued → running → blocked → complete | failed | cancelled`) that can bind to
   payment, escrow, and reputation events.
 - **`AgentStack`** — an in-memory coordinator that registers agents, tracks tasks, records
-  delegation grants, and emits coordination events. Storage backends can wrap the same API.
+  delegation grants, checks active scoped authority, and emits coordination events. Storage
+  backends can wrap the same API.
 - **`agentStackPlugin`** — a LogicSRC `PluginDefinition` (validated against the plugin
   manifest schema) exposing AgentStack as a coordination plugin with routes, events,
   permissions, and a TUI panel.
@@ -39,6 +40,10 @@ const task = stack.createTask({ ownerDid: owner, sourceApp: "sh1pt.com", title:
 stack.assignTask(task.id, agentDid("abc"));
 stack.updateTaskStatus(task.id, "running");
 stack.updateTaskStatus(task.id, "complete", { reputationEventId: "rep_1" });
+
+const grant = stack.delegate(owner, agentDid("abc"), ["tasks:create"]);
+stack.hasDelegation(owner, agentDid("abc"), "tasks:create"); // true while the grant is active
+stack.revokeDelegation(grant.id);
 ```
 
 ## Cross-app identity
diff --git a/packages/agentstack/src/index.test.ts b/packages/agentstack/src/index.test.ts
index b262257..0da66cf 100644
--- a/packages/agentstack/src/index.test.ts
+++ b/packages/agentstack/src/index.test.ts
@@ -120,15 +120,38 @@ describe("AgentStack coordinator", () => {
   it("records delegation grants and emits events", () => {
     const stack = new AgentStack();
     const listener = vi.fn();
-    stack.on(listener);
-    stack.registerAgent(agent);
-    const grant = stack.delegate(owner, agent.did, ["tasks:create"]);
-
-    expect(grant.ownerDid).toBe(owner);
-    expect(grant.agentDid).toBe(agent.did);
-    expect(listener).toHaveBeenCalledWith(expect.objectContaining({ type: "agent.registered" }));
-    expect(listener).toHaveBeenCalledWith(expect.objectContaining({ type: "delegation.granted" }));
-  });
+    stack.on(listener);
+    stack.registerAgent(agent);
+    const grant = stack.delegate(owner, agent.did, ["tasks:create"]);
+
+    expect(grant.ownerDid).toBe(owner);
+    expect(grant.agentDid).toBe(agent.did);
+    expect(listener).toHaveBeenCalledWith(expect.objectContaining({ type: "agent.registered" }));
+    expect(listener).toHaveBeenCalledWith(expect.objectContaining({ type: "delegation.granted" }));
+  });
+
+  it("checks active delegation authority by owner, agent, scope, and expiry", () => {
+    const stack = new AgentStack(() => "2026-01-01T00:00:00.000Z");
+    stack.registerAgent(agent);
+
+    stack.delegate(owner, agent.did, ["tasks:create"], "2026-01-02T00:00:00.000Z");
+
+    expect(stack.hasDelegation(owner, agent.did, "tasks:create")).toBe(true);
+    expect(stack.hasDelegation(owner, agent.did, "tasks:update")).toBe(false);
+    expect(stack.hasDelegation(owner, agent.did, "tasks:create", "2026-01-03T00:00:00.000Z")).toBe(false);
+    expect(stack.listDelegations({ ownerDid: owner, agentDid: agent.did, scope: "tasks:create" })).toHaveLength(1);
+    expect(stack.listDelegations({ activeAt: "2026-01-03T00:00:00.000Z" })).toHaveLength(0);
+  });
+
+  it("allows wildcard delegation scopes and ignores revoked grants", () => {
+    const stack = new AgentStack();
+    stack.registerAgent(agent);
+    const grant = stack.delegate(owner, agent.did, ["*"]);
+
+    expect(stack.hasDelegation(owner, agent.did, "tasks:update")).toBe(true);
+    stack.revokeDelegation(grant.id);
+    expect(stack.hasDelegation(owner, agent.did, "tasks:update")).toBe(false);
+  });
 
   it("rejects unknown agents and invalid DIDs", () => {
     const stack = new AgentStack();
diff --git a/packages/agentstack/src/index.ts b/packages/agentstack/src/index.ts
index 1aec33d..49d3473 100644
--- a/packages/agentstack/src/index.ts
+++ b/packages/agentstack/src/index.ts
@@ -178,18 +178,46 @@ export class AgentStack {
     return grant;
   }
 
-  revokeDelegation(grantId: string): DelegationGrant {
-    const grant = this.delegations.get(grantId);
-    if (!grant) throw new Error(`Unknown delegation grant: ${grantId}`);
-    this.delegations.delete(grantId);
-    this.emit({ type: "delegation.revoked", grant });
-    return grant;
-  }
-
-  listTasks(filter?: { ownerDid?: string; assigneeDid?: string; status?: TaskStatus }): DidTask[] {
-    return [...this.tasks.values()].filter((task) => {
-      if (filter?.ownerDid && task.ownerDid !== filter.ownerDid) return false;
-      if (filter?.assigneeDid && task.assigneeDid !== filter.assigneeDid) return false;
+  revokeDelegation(grantId: string): DelegationGrant {
+    const grant = this.delegations.get(grantId);
+    if (!grant) throw new Error(`Unknown delegation grant: ${grantId}`);
+    this.delegations.delete(grantId);
+    this.emit({ type: "delegation.revoked", grant });
+    return grant;
+  }
+
+  listDelegations(filter?: {
+    ownerDid?: string;
+    agentDid?: string;
+    scope?: string;
+    activeAt?: string;
+  }): DelegationGrant[] {
+    return [...this.delegations.values()].filter((grant) => {
+      if (filter?.ownerDid && grant.ownerDid !== filter.ownerDid) return false;
+      if (filter?.agentDid && grant.agentDid !== filter.agentDid) return false;
+      if (filter?.scope && !this.grantAllowsScope(grant, filter.scope)) return false;
+      if (filter?.activeAt && !this.grantIsActive(grant, filter.activeAt)) return false;
+      return true;
+    });
+  }
+
+  hasDelegation(ownerDidValue: string, agentDidValue: string, scope: string, at: string = this.now()): boolean {
+    if (!parseDid(ownerDidValue)) throw new Error(`Invalid owner DID: ${ownerDidValue}`);
+    if (!this.agents.has(agentDidValue)) throw new Error(`Unknown agent: ${agentDidValue}`);
+    return (
+      this.listDelegations({
+        ownerDid: ownerDidValue,
+        agentDid: agentDidValue,
+        scope,
+        activeAt: at
+      }).length > 0
+    );
+  }
+
+  listTasks(filter?: { ownerDid?: string; assigneeDid?: string; status?: TaskStatus }): DidTask[] {
+    return [...this.tasks.values()].filter((task) => {
+      if (filter?.ownerDid && task.ownerDid !== filter.ownerDid) return false;
+      if (filter?.assigneeDid && task.assigneeDid !== filter.assigneeDid) return false;
       if (filter?.status && task.status !== filter.status) return false;
       return true;
     });
@@ -205,10 +233,18 @@ export class AgentStack {
 
   private requireTask(id: string): DidTask {
     const task = this.tasks.get(id);
-    if (!task) throw new Error(`Unknown task: ${id}`);
-    return task;
-  }
-}
+    if (!task) throw new Error(`Unknown task: ${id}`);
+    return task;
+  }
+
+  private grantAllowsScope(grant: DelegationGrant, scope: string): boolean {
+    return grant.scopes.includes(scope) || grant.scopes.includes("*");
+  }
+
+  private grantIsActive(grant: DelegationGrant, at: string): boolean {
+    return !grant.expiresAt || grant.expiresAt > at;
+  }
+}
 
 /** LogicSRC plugin definition exposing AgentStack as a coordination plugin. */
 export const agentStackPlugin: PluginDefinition = {