diff --git a/packages/opencode/test/cli/skill.test.ts b/packages/opencode/test/cli/skill.test.ts
index 6a04bd364..f71e93390 100644
--- a/packages/opencode/test/cli/skill.test.ts
+++ b/packages/opencode/test/cli/skill.test.ts
@@ -3,7 +3,8 @@ import { describe, test, expect } from "bun:test"
 import fs from "fs/promises"
 import path from "path"
 import { tmpdir } from "../fixture/fixture"
-import { detectToolReferences, SHELL_BUILTINS } from "../../src/cli/cmd/skill-helpers"
+import { detectToolReferences, SHELL_BUILTINS, skillSource } from "../../src/cli/cmd/skill-helpers"
+import os from "os"
 
 // ---------------------------------------------------------------------------
 // Unit tests — import production code directly (no duplication)
@@ -456,6 +457,44 @@ describe("skill install — symlink safety", () => {
   })
 })
 
+// ---------------------------------------------------------------------------
+// skillSource trust classification — determines builtin / global / project label
+// ---------------------------------------------------------------------------
+
+describe("skillSource", () => {
+  // Global.Path.home reads process.env.OPENCODE_TEST_HOME || os.homedir()
+  const home = process.env.OPENCODE_TEST_HOME || os.homedir()
+
+  test("builtin: prefix → builtin", () => {
+    expect(skillSource("builtin:dbt-run")).toBe("builtin")
+    expect(skillSource("builtin:")).toBe("builtin")
+  })
+
+  test("~/.altimate/builtin/... → builtin", () => {
+    expect(skillSource(path.join(home, ".altimate", "builtin", "dbt-run", "SKILL.md"))).toBe("builtin")
+  })
+
+  test("~/.claude/skills/... → global", () => {
+    expect(skillSource(path.join(home, ".claude", "skills", "my-skill", "SKILL.md"))).toBe("global")
+  })
+
+  test("~/.agents/skills/... → global", () => {
+    expect(skillSource(path.join(home, ".agents", "skills", "my-skill", "SKILL.md"))).toBe("global")
+  })
+
+  test("~/.altimate-code/skills/... → global", () => {
+    expect(skillSource(path.join(home, ".altimate-code", "skills", "custom", "SKILL.md"))).toBe("global")
+  })
+
+  test("project path → project", () => {
+    expect(skillSource("/home/user/myproject/.opencode/skills/custom/SKILL.md")).toBe("project")
+  })
+
+  test("random path with no skill dir match → project", () => {
+    expect(skillSource("/tmp/something/SKILL.md")).toBe("project")
+  })
+})
+
 describe("GitHub URL normalization", () => {
   test("extracts owner/repo from web URLs", () => {
     const re = /^https?:\/\/github\.com\/([^/]+\/[^/]+?)(?:\/(?:tree|blob)\/.*)?$/
diff --git a/packages/opencode/test/util/fn.test.ts b/packages/opencode/test/util/fn.test.ts
new file mode 100644
index 000000000..c24b71275
--- /dev/null
+++ b/packages/opencode/test/util/fn.test.ts
@@ -0,0 +1,32 @@
+import { describe, test, expect } from "bun:test"
+import { z } from "zod"
+import { fn } from "../../src/util/fn"
+
+describe("fn: zod-validated function wrapper", () => {
+  test("passes validated input to callback", () => {
+    const add = fn(z.object({ a: z.number(), b: z.number() }), ({ a, b }) => a + b)
+    expect(add({ a: 1, b: 2 })).toBe(3)
+  })
+
+  test("throws ZodError on invalid input", () => {
+    const greet = fn(z.object({ name: z.string() }), ({ name }) => `hi ${name}`)
+    expect(() => greet({ name: 42 } as any)).toThrow()
+  })
+
+  test(".force() bypasses validation", () => {
+    const double = fn(z.number().int(), (n) => n * 2)
+    // 1.5 is not an int, but .force skips validation
+    expect(double.force(1.5)).toBe(3)
+  })
+
+  test(".schema exposes the original zod schema", () => {
+    const schema = z.string().email()
+    const validate = fn(schema, (s) => s.toUpperCase())
+    expect(validate.schema).toBe(schema)
+  })
+
+  test("rejects unknown keys with strict schema", () => {
+    const strict = fn(z.object({ id: z.number() }).strict(), ({ id }) => id)
+    expect(() => strict({ id: 1, extra: true } as any)).toThrow()
+  })
+})