diff --git a/apps/web/src/agent-deploy.test.ts b/apps/web/src/agent-deploy.test.ts
index df152874f..1133b6116 100644
--- a/apps/web/src/agent-deploy.test.ts
+++ b/apps/web/src/agent-deploy.test.ts
@@ -4,6 +4,7 @@ import {
   agentDeploySourceAssetName,
   agentSlugFromSourceAssetName,
   buildAgentDefinitionJson,
+  buildScheduledRunBody,
 } from "./agent-deploy";
 
 describe("buildAgentDefinitionJson", () => {
@@ -34,6 +35,20 @@ describe("buildAgentDefinitionJson", () => {
   });
 });
 
+describe("buildScheduledRunBody", () => {
+  test("asks the agent to mail the deploying person's address", () => {
+    const body = buildScheduledRunBody("alice@example.test");
+    expect(body).toContain("alice@example.test");
+    expect(body).toContain("`to` list");
+  });
+
+  test("falls back to a bare reply instruction when no address is known", () => {
+    const body = buildScheduledRunBody(undefined);
+    expect(body).not.toContain("@");
+    expect(body).toContain("Reply with the result.");
+  });
+});
+
 describe("agentSlugFromSourceAssetName", () => {
   test("recovers the slug agentDeploySourceAssetName wrapped", () => {
     expect(agentSlugFromSourceAssetName(agentDeploySourceAssetName("echo-bot"))).toBe("echo-bot");
diff --git a/apps/web/src/agent-deploy.ts b/apps/web/src/agent-deploy.ts
index 3081eab53..fb55a3cfa 100644
--- a/apps/web/src/agent-deploy.ts
+++ b/apps/web/src/agent-deploy.ts
@@ -7,6 +7,7 @@
 import { renderBundledWorkflowSourceTree } from "@corbits/workflows/client";
 import { type } from "arktype";
 import { WorkflowDeploymentResponse } from "@intx/types";
+import { reportError } from "@corbits/error-sink";
 
 import { resolveExistingOffering } from "./onboarding/provider-connect-step";
 import { isValidSlug, slugify } from "@/lib/slug";
@@ -17,6 +18,10 @@ const AssetCreatedShape = type({ id: "string" });
 const AssetListShape = type({ id: "string", name: "string" }).array();
 const GitTokenMintShape = type({ id: "string", secret: "string" });
 const TenantDomainShape = type({ domain: "string" });
+// Same shape `session.ts`'s `fetchSession` parses; a person's refId is
+// their better-auth user id, exactly what `threads-api.ts` builds a
+// principal's mailbox address from.
+const SessionUserShape = type({ user: { id: "string" } });
 
 const PUSH_TOKEN_LIFETIME_MS = 10 * 60 * 1000;
 
@@ -241,6 +246,48 @@ function cronPath(tenantId: string): string {
   return `/api/tenants/${encodeURIComponent(tenantId)}/cron`;
 }
 
+/** The scheduled-run mail body: names the person to report to (when known)
+ * so the agent's reply has somewhere routable to go, since the cron
+ * sender itself has no mailbox. */
+export function buildScheduledRunBody(deployerAddress?: string): string {
+  const task = "Do the work your definition describes.";
+  if (deployerAddress === undefined) {
+    return `This is your scheduled run. ${task} Reply with the result.`;
+  }
+  return `This is your scheduled run. ${task} Mail the result to ${deployerAddress} (pass it as a single-item \`to\` list) with a short, descriptive subject.`;
+}
+
+/** The deploying person's mailbox address — same source `session.ts`'s
+ * `fetchSession` reads, same shape `threads-api.ts` builds a person
+ * participant's address from (`<refId>@<tenantDomain>`). Best-effort: a
+ * session probe that fails or comes back signed-out just means the
+ * scheduled run's body falls back to naming nobody, never a failed
+ * deploy over it. */
+async function resolveDeployerAddress(
+  tenantDomain: string,
+  fetchImpl: typeof fetch,
+): Promise<string | undefined> {
+  let response: Response;
+  try {
+    response = await fetchImpl("/api/auth/get-session", {
+      headers: { accept: "application/json" },
+    });
+  } catch (cause) {
+    reportError(cause, { operation: "agent_deploy_resolve_deployer_address" });
+    return undefined;
+  }
+  if (!response.ok) return undefined;
+  let body: unknown;
+  try {
+    body = await response.json();
+  } catch (cause) {
+    reportError(cause, { operation: "agent_deploy_resolve_deployer_address" });
+    return undefined;
+  }
+  const parsed = SessionUserShape(body);
+  return parsed instanceof type.errors ? undefined : `${parsed.user.id}@${tenantDomain}`;
+}
+
 /** Creates a `@corbits/cron` schedule row addressed at a deployed agent's
  * run — the only way an agent fires on a cadence, since Interchange's
  * `schedule` trigger is reserved but unimplemented. */
@@ -248,8 +295,10 @@ async function scheduleAgentRun(
   tenantId: string,
   expression: string,
   runAddress: string,
+  tenantDomain: string,
   fetchImpl: typeof fetch,
 ): Promise<void> {
+  const deployerAddress = await resolveDeployerAddress(tenantDomain, fetchImpl);
   const created = await fetchImpl(cronPath(tenantId), {
     method: "POST",
     headers: { "content-type": "application/json" },
@@ -257,7 +306,7 @@ async function scheduleAgentRun(
       expression,
       toAddress: runAddress,
       subject: "Scheduled run",
-      body: "This is your scheduled run. Do the work your definition describes and reply with the result.",
+      body: buildScheduledRunBody(deployerAddress),
     }),
   });
   if (!created.ok) {
@@ -346,6 +395,7 @@ export async function deployAgentSource(
       // The deployment id is the top-level run id (already `run_…`), and
       // the run address is that id at the tenant domain.
       `${parsed.id}@${tenant.domain}`,
+      tenant.domain,
       fetchImpl,
     );
   }