feat(core): support pinned Code Mode tools (#39550)

packages/core/test/codemode.test.ts

@@ -16,6 +16,7 @@ describe("CodeMode", () => {
             description: "Echo text",
             input: Schema.Struct({ text: Schema.String }),
             output: Schema.String,
+            options: { pinned: true },
             execute: ({ text }) => Effect.succeed({ output: text }),
         }),
       )
@@ -27,6 +28,7 @@ describe("CodeMode", () => {
           path: "echo",
           description: "Echo text",
           signature: "tools.echo(input: {\n  text: string,\n}): Promise<string>",
+          pinned: true,
         },
       ])
     }).pipe(

packages/core/test/codemode/catalog.test.ts

@@ -2,10 +2,11 @@ import { describe, expect, test } from "bun:test"
 import { CodeModeCatalog } from "@opencode-ai/core/codemode/catalog"
 import { CodeModeInstructions } from "@opencode-ai/core/codemode/instructions"
 
-const entry = (path: string, description: string, signature?: string): CodeModeCatalog.Entry => ({
+const entry = (path: string, description: string, signature?: string, pinned = false): CodeModeCatalog.Entry => ({
   path,
   description,
   signature: signature ?? `tools.${path}(input: {\n  q: string,\n}): Promise<string>`,
+  pinned,
 })
 
 const lookup = entry(
@@ -46,6 +47,30 @@ describe("CodeModeCatalog.summarize", () => {
     expect(catalog.namespaces.every((namespace) => namespace.entries.length === 0)).toBe(true)
   })
 
+  test("always retains pinned tools beyond the inline budget", () => {
+    const pinned = [
+      entry("alpha.first", "First", undefined, true),
+      entry("beta.second", "Second", undefined, true),
+    ]
+    const catalog = CodeModeCatalog.summarize([...pinned, entry("alpha.unpinned", "Unpinned")], 0)
+
+    expect(catalog.shown).toBe(2)
+    expect(catalog.namespaces.flatMap((namespace) => namespace.entries.map((item) => item.path))).toEqual([
+      "alpha.first",
+      "beta.second",
+    ])
+  })
+
+  test("spends the budget remaining after pinned tools on unpinned tools", () => {
+    const pinned = entry("alpha.pinned", "Pinned", undefined, true)
+    const unpinned = entry("beta.unpinned", "Unpinned")
+    const pinCost = Math.round(`  - ${pinned.signature} // Pinned`.length / 4)
+    const unpinnedCost = Math.round(`  - ${unpinned.signature} // Unpinned`.length / 4)
+
+    expect(CodeModeCatalog.summarize([pinned, unpinned], pinCost + unpinnedCost).shown).toBe(2)
+    expect(CodeModeCatalog.summarize([pinned, unpinned], pinCost + unpinnedCost - 1).shown).toBe(1)
+  })
+
   test("retains only the rendered portion of inline descriptions", () => {
     const catalog = CodeModeCatalog.summarize([entry("alpha.one", `Summary\n${"detail".repeat(10_000)}`)])
     expect(catalog.namespaces[0]?.entries[0]?.line).toEndWith("// Summary")

packages/core/test/session-runner-tool-registry.test.ts

@@ -67,7 +67,7 @@ const transform = (
 ) =>
   service.transform((draft) =>
     Object.entries(tools).forEach(([name, tool]) =>
-      draft.add({ ...tool, name, options: { ...tool.options, ...options } }),
+      draft.add({ ...tool, name, options: options ?? tool.options }),
     ),
   )
 

packages/core/test/session-runner.test.ts

@@ -231,7 +231,7 @@ const permission = Layer.succeed(
 const transformTools = (registry: Tool.Interface, tools: Readonly<Record<string, Info>>, options?: Tool.Options) =>
   registry.transform((draft) =>
     Object.entries(tools).forEach(([name, tool]) =>
-      draft.add({ ...tool, name, options: { ...tool.options, ...options } }),
+      draft.add({ ...tool, name, options: options ?? tool.options }),
     ),
   )
 const echo = Layer.effectDiscard(