From 319be994b6d51415b60e03b488754d2fcfb09869 Mon Sep 17 00:00:00 2001
From: Aiden Cline <aidenpcline@gmail.com>
Date: Mon, 29 Jun 2026 16:57:25 -0500
Subject: [PATCH] fix(core): migrate bare v1-shaped mcp config blocks

isV1 only triggered on a fixed set of top-level keys, so a config with just
$schema and a v1-shaped mcp block (servers directly under mcp, with enabled)
was parsed as v2 and silently produced zero servers. Detect the v1 mcp shape
(no servers wrapper, entries with a type) so these files migrate correctly.
---
 packages/core/src/v1/config/migrate.ts   | 14 +++++++++++++-
 packages/core/test/config/config.test.ts | 12 ++++++++++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/packages/core/src/v1/config/migrate.ts b/packages/core/src/v1/config/migrate.ts
index 5f62858e3c..2a9e1c7383 100644
--- a/packages/core/src/v1/config/migrate.ts
+++ b/packages/core/src/v1/config/migrate.ts
@@ -29,7 +29,19 @@ const keys = new Set([
 
 export function isV1(input: unknown) {
   if (typeof input !== "object" || input === null || Array.isArray(input)) return false
-  return Object.keys(input).some((key) => keys.has(key))
+  const record = input as Record<string, unknown>
+  if (Object.keys(record).some((key) => keys.has(key))) return true
+  // `mcp` exists in both versions, so presence alone is ambiguous: v1 lists servers directly under
+  // `mcp`, while v2 nests them under `mcp.servers`. Only the v1 shape (a server entry with `type`)
+  // counts, so a bare `mcp`-only file still migrates instead of silently parsing to zero servers.
+  const mcp = record.mcp
+  return (
+    typeof mcp === "object" &&
+    mcp !== null &&
+    !Array.isArray(mcp) &&
+    !("servers" in mcp) &&
+    Object.values(mcp).some((server) => typeof server === "object" && server !== null && "type" in server)
+  )
 }
 
 export function migrate(info: typeof ConfigV1.Info.Type) {
diff --git a/packages/core/test/config/config.test.ts b/packages/core/test/config/config.test.ts
index 0f61c6c1df..f16312b763 100644
--- a/packages/core/test/config/config.test.ts
+++ b/packages/core/test/config/config.test.ts
@@ -76,6 +76,18 @@ describe("Config", () => {
     }),
   )
 
+  it.effect("detects a bare v1-shaped mcp block while leaving v2 mcp config alone", () =>
+    Effect.sync(() => {
+      // V1 lists servers directly under `mcp`, so a file with only `$schema` + `mcp` still migrates.
+      expect(ConfigMigrateV1.isV1({ mcp: { context7: { type: "local", command: ["npx"] } } })).toBe(true)
+      expect(ConfigMigrateV1.isV1({ $schema: "x", mcp: { executor: { type: "remote", url: "https://x" } } })).toBe(true)
+      // V2 nests under `mcp.servers`, so it must not be misdetected and re-migrated.
+      expect(ConfigMigrateV1.isV1({ mcp: { servers: { context7: { type: "local", command: ["npx"] } } } })).toBe(false)
+      expect(ConfigMigrateV1.isV1({ mcp: {} })).toBe(false)
+      expect(ConfigMigrateV1.isV1({ mcp: { timeout: { request: 1000 } } })).toBe(false)
+    }),
+  )
+
   it.effect("migrates arbitrary v1 configuration into valid v2 configuration", () =>
     Effect.sync(() => {
       FastCheck.assert(