Feat/set session title

packages/opencode/src/session/prompt.ts

@@ -1786,7 +1786,8 @@ NOTE: At any point in time through this workflow you should feel free to ask the
         if (!cleaned) return
 
         const title = cleaned.length > 100 ? cleaned.substring(0, 97) + "..." : cleaned
-        draft.title = title
+        // Only set if title is still default (wasn't changed by tool during LLM call)
+        if (Session.isDefaultTitle(draft.title)) draft.title = title
       })
   }
 }

packages/opencode/src/tool/registry.ts

@@ -26,6 +26,7 @@ import { Log } from "@/util/log"
 import { LspTool } from "./lsp"
 import { Truncate } from "./truncation"
 import { PlanExitTool, PlanEnterTool } from "./plan"
+import { SetCurrentSessionTitleTool } from "./set-current-session-title"
 
 export namespace ToolRegistry {
   const log = Log.create({ service: "tool.registry" })
@@ -105,6 +106,7 @@ export namespace ToolRegistry {
       WebFetchTool,
       TodoWriteTool,
       TodoReadTool,
+      SetCurrentSessionTitleTool,
       WebSearchTool,
       CodeSearchTool,
       SkillTool,

packages/opencode/src/tool/set-current-session-title.ts

@@ -0,0 +1,36 @@
+import z from "zod"
+import { Tool } from "./tool"
+import { Session } from "../session"
+import DESCRIPTION from "./set-current-session-title.txt"
+
+export const SetCurrentSessionTitleTool = Tool.define("set_current_session_title", {
+  description: DESCRIPTION,
+  parameters: z.object({
+    title: z
+      .string()
+      .min(1, "Title must be at least 1 character")
+      .max(255, "Title must be at most 255 characters")
+      .describe("The new title for the current session"),
+  }),
+  async execute(params, ctx) {
+    await ctx.ask({
+      permission: "set_current_session_title",
+      patterns: ["*"],
+      always: ["*"],
+      metadata: {},
+    })
+
+    const session = await Session.update(ctx.sessionID, (draft) => {
+      draft.title = params.title
+    })
+
+    return {
+      title: params.title,
+      output: `Session title updated to: ${session.title}`,
+      metadata: {
+        sessionID: ctx.sessionID,
+        title: session.title,
+      },
+    }
+  },
+})

packages/opencode/src/tool/set-current-session-title.txt

@@ -0,0 +1,8 @@
+Sets the title of the current session.
+
+Use this tool to give the session a descriptive title that reflects its purpose or content, or when the user asks you to set the session's title. The title will be immediately visible in the UI.
+
+Usage notes:
+- The title must be between 1 and 255 characters
+- Choose a concise, descriptive title that helps identify the session's purpose
+- This is useful in custom slash commands to automatically title sessions based on their context

packages/opencode/test/tool/set-current-session-title.test.ts

@@ -0,0 +1,161 @@
+import { describe, expect, test } from "bun:test"
+import { SetCurrentSessionTitleTool } from "../../src/tool/set-current-session-title"
+import { Instance } from "../../src/project/instance"
+import { Session } from "../../src/session"
+import { tmpdir } from "../fixture/fixture"
+
+describe("tool.set_current_session_title", () => {
+  test("updates session title", async () => {
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const tool = await SetCurrentSessionTitleTool.init()
+        const ctx = {
+          sessionID: session.id,
+          messageID: "",
+          callID: "",
+          agent: "build",
+          abort: AbortSignal.any([]),
+          metadata: () => {},
+          ask: async () => {},
+        }
+
+        const result = await tool.execute({ title: "My Test Session" }, ctx)
+
+        expect(result.title).toBe("My Test Session")
+        expect(result.output).toContain("My Test Session")
+
+        const updated = await Session.get(session.id)
+        expect(updated.title).toBe("My Test Session")
+      },
+    })
+  })
+
+  test("rejects empty title", async () => {
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const tool = await SetCurrentSessionTitleTool.init()
+        const ctx = {
+          sessionID: session.id,
+          messageID: "",
+          callID: "",
+          agent: "build",
+          abort: AbortSignal.any([]),
+          metadata: () => {},
+          ask: async () => {},
+        }
+
+        await expect(tool.execute({ title: "" }, ctx)).rejects.toThrow()
+      },
+    })
+  })
+
+  test("rejects title exceeding 255 characters", async () => {
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const tool = await SetCurrentSessionTitleTool.init()
+        const ctx = {
+          sessionID: session.id,
+          messageID: "",
+          callID: "",
+          agent: "build",
+          abort: AbortSignal.any([]),
+          metadata: () => {},
+          ask: async () => {},
+        }
+
+        const longTitle = "a".repeat(256)
+        await expect(tool.execute({ title: longTitle }, ctx)).rejects.toThrow()
+      },
+    })
+  })
+
+  test("accepts title with exactly 255 characters", async () => {
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const tool = await SetCurrentSessionTitleTool.init()
+        const ctx = {
+          sessionID: session.id,
+          messageID: "",
+          callID: "",
+          agent: "build",
+          abort: AbortSignal.any([]),
+          metadata: () => {},
+          ask: async () => {},
+        }
+
+        const maxTitle = "a".repeat(255)
+        const result = await tool.execute({ title: maxTitle }, ctx)
+
+        expect(result.title).toBe(maxTitle)
+        const updated = await Session.get(session.id)
+        expect(updated.title).toBe(maxTitle)
+      },
+    })
+  })
+
+  test("accepts single character title", async () => {
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const tool = await SetCurrentSessionTitleTool.init()
+        const ctx = {
+          sessionID: session.id,
+          messageID: "",
+          callID: "",
+          agent: "build",
+          abort: AbortSignal.any([]),
+          metadata: () => {},
+          ask: async () => {},
+        }
+
+        const result = await tool.execute({ title: "X" }, ctx)
+
+        expect(result.title).toBe("X")
+        const updated = await Session.get(session.id)
+        expect(updated.title).toBe("X")
+      },
+    })
+  })
+
+  test("asks for permission", async () => {
+    await using tmp = await tmpdir({ git: true })
+    await Instance.provide({
+      directory: tmp.path,
+      fn: async () => {
+        const session = await Session.create({})
+        const tool = await SetCurrentSessionTitleTool.init()
+        const requests: Array<{ permission: string }> = []
+        const ctx = {
+          sessionID: session.id,
+          messageID: "",
+          callID: "",
+          agent: "build",
+          abort: AbortSignal.any([]),
+          metadata: () => {},
+          ask: async (req: { permission: string }) => {
+            requests.push(req)
+          },
+        }
+
+        await tool.execute({ title: "Test Title" }, ctx)
+
+        expect(requests.length).toBe(1)
+        expect(requests[0].permission).toBe("set_current_session_title")
+      },
+    })
+  })
+})