diff --git a/packages/adapters/src/agent-environment.test.ts b/packages/adapters/src/agent-environment.test.ts
index a940c9c..a9660d7 100644
--- a/packages/adapters/src/agent-environment.test.ts
+++ b/packages/adapters/src/agent-environment.test.ts
@@ -1,11 +1,19 @@
 import { describe, expect, it } from "vitest";
 import {
+  agentSecretScopeForRun,
   decryptAgentEnvironment,
   formatAgentEnvironmentInstruction,
   redactAgentCommandResult,
 } from "./agent-environment.js";
 
 describe("agent-environment", () => {
+  it("scopes agent secrets to the run owner in shared Spaces", () => {
+    expect(agentSecretScopeForRun("shared-ws", "member-user")).toEqual({
+      spaceId: "shared-ws",
+      createdByUserId: "member-user",
+    });
+  });
+
   it("decrypts named agent secrets", () => {
     const env = decryptAgentEnvironment(
       [
diff --git a/packages/adapters/src/agent-environment.ts b/packages/adapters/src/agent-environment.ts
index 0c839d3..031b078 100644
--- a/packages/adapters/src/agent-environment.ts
+++ b/packages/adapters/src/agent-environment.ts
@@ -10,6 +10,10 @@ type SecretLoader = {
   load(ciphertext: string, recordId: string): string;
 };
 
+export function agentSecretScopeForRun(spaceId: string, userId: string) {
+  return { spaceId, createdByUserId: userId };
+}
+
 export function decryptAgentEnvironment(
   rows: EncryptedAgentSecret[],
   secrets: SecretLoader,
diff --git a/packages/adapters/src/executor.ts b/packages/adapters/src/executor.ts
index f55e5ee..1a2a6b5 100644
--- a/packages/adapters/src/executor.ts
+++ b/packages/adapters/src/executor.ts
@@ -108,6 +108,7 @@ import {
   respondAgentConnection,
 } from "./agent-connections.js";
 import {
+  agentSecretScopeForRun,
   decryptAgentEnvironment,
   formatAgentEnvironmentInstruction,
   redactAgentCommandResult,
@@ -1029,7 +1030,7 @@ export function createRunExecutor(deps: ExecutorDeps) {
             userId: run.userId,
           }),
           deps.prisma.agentSecret.findMany({
-            where: { spaceId: run.spaceId },
+            where: agentSecretScopeForRun(run.spaceId, run.userId),
             select: {
               name: true,
               secret: { select: { id: true, ciphertext: true } },