diff --git a/packages/musher/src/bundle.ts b/packages/musher/src/bundle.ts
index 808f7bd..8c46d2d 100644
--- a/packages/musher/src/bundle.ts
+++ b/packages/musher/src/bundle.ts
@@ -88,7 +88,7 @@ export class Bundle {
 					this._toolsets.set(name, new ToolsetHandle(name, fh));
 					break;
 				}
-				case "agent_definition": {
+				case "agent_spec": {
 					const name = baseFileName(fh.logicalPath);
 					this._agentSpecs.set(name, new AgentSpecHandle(name, fh));
 					break;
diff --git a/packages/musher/src/handles/agent-spec-handle.ts b/packages/musher/src/handles/agent-spec-handle.ts
index e6a987c..f008327 100644
--- a/packages/musher/src/handles/agent-spec-handle.ts
+++ b/packages/musher/src/handles/agent-spec-handle.ts
@@ -1,5 +1,5 @@
 /**
- * AgentSpecHandle — wraps a single agent_definition asset.
+ * AgentSpecHandle — wraps a single agent_spec asset.
  */
 
 import type { FileHandle } from "./file-handle.js";
diff --git a/packages/musher/src/schemas/common.ts b/packages/musher/src/schemas/common.ts
index 4748e8f..bf69766 100644
--- a/packages/musher/src/schemas/common.ts
+++ b/packages/musher/src/schemas/common.ts
@@ -7,7 +7,7 @@ export const BundleVisibility = z.enum(["private", "public"]);
 export const BundleVersionState = z.enum(["published", "yanked"]);
 
 export const AssetType = z.enum([
-	"agent_definition",
+	"agent_spec",
 	"skill",
 	"tool_config",
 	"prompt",
diff --git a/packages/musher/tests/bundle.test.ts b/packages/musher/tests/bundle.test.ts
index a855bed..3731ca3 100644
--- a/packages/musher/tests/bundle.test.ts
+++ b/packages/musher/tests/bundle.test.ts
@@ -62,7 +62,7 @@ function makeManifest(): BundleResolveOutput {
 				{
 					assetId: "asset-005",
 					logicalPath: "agents/main.yaml",
-					assetType: "agent_definition",
+					assetType: "agent_spec",
 					contentSha256: sha(AGENT_CONTENT),
 					sizeBytes: AGENT_CONTENT.length,
 				},
diff --git a/packages/musher/tests/handles.test.ts b/packages/musher/tests/handles.test.ts
index 92f4d6d..4e3fad3 100644
--- a/packages/musher/tests/handles.test.ts
+++ b/packages/musher/tests/handles.test.ts
@@ -90,7 +90,7 @@ describe("ToolsetHandle", () => {
 
 describe("AgentSpecHandle", () => {
 	it("wraps a single file", () => {
-		const fh = new FileHandle("agent.yaml", "agent_definition", "x", 4, Buffer.from("name"));
+		const fh = new FileHandle("agent.yaml", "agent_spec", "x", 4, Buffer.from("name"));
 		const spec = new AgentSpecHandle("agent", fh);
 
 		expect(spec.name).toBe("agent");