feat: Add ACP (Agent Client Protocol) support (#2947)

Co-authored-by: opencode-bot <devnull@opencode.local>
Co-authored-by: Dax Raad <d@ironbay.co>
Co-authored-by: GitHub Action <action@github.com>

packages/opencode/test/acp.test.ts

@@ -0,0 +1,109 @@
+import { describe, expect, test } from "bun:test"
+import { spawn } from "child_process"
+
+describe("ACP Server", () => {
+  test("initialize and shutdown", async () => {
+    const proc = spawn("bun", ["run", "--conditions=development", "src/index.ts", "acp"], {
+      cwd: process.cwd(),
+      stdio: ["pipe", "pipe", "pipe"],
+      env: { ...process.env, OPENCODE: "1" },
+    })
+
+    const encoder = new TextEncoder()
+    const decoder = new TextDecoder()
+
+    let initResponse: any = null
+
+    proc.stdout.on("data", (chunk: Buffer) => {
+      const lines = decoder.decode(chunk).split("\n")
+      for (const line of lines) {
+        const trimmed = line.trim()
+        if (!trimmed) continue
+
+        try {
+          const msg = JSON.parse(trimmed)
+          if (msg.id === 1) initResponse = msg
+        } catch (e) {}
+      }
+    })
+
+    proc.stdin.write(
+      encoder.encode(
+        JSON.stringify({
+          jsonrpc: "2.0",
+          id: 1,
+          method: "initialize",
+          params: { protocolVersion: 1 },
+        }) + "\n",
+      ),
+    )
+
+    await new Promise((resolve) => setTimeout(resolve, 500))
+
+    expect(initResponse).toBeTruthy()
+    expect(initResponse.result.protocolVersion).toBe(1)
+    expect(initResponse.result.agentCapabilities).toBeTruthy()
+
+    proc.kill()
+  }, 10000)
+
+  test("create session", async () => {
+    const proc = spawn("bun", ["run", "--conditions=development", "src/index.ts", "acp"], {
+      cwd: process.cwd(),
+      stdio: ["pipe", "pipe", "pipe"],
+      env: { ...process.env, OPENCODE: "1" },
+    })
+
+    const encoder = new TextEncoder()
+    const decoder = new TextDecoder()
+
+    let sessionResponse: any = null
+
+    proc.stdout.on("data", (chunk: Buffer) => {
+      const lines = decoder.decode(chunk).split("\n")
+      for (const line of lines) {
+        const trimmed = line.trim()
+        if (!trimmed) continue
+
+        try {
+          const msg = JSON.parse(trimmed)
+          if (msg.id === 2) sessionResponse = msg
+        } catch (e) {}
+      }
+    })
+
+    proc.stdin.write(
+      encoder.encode(
+        JSON.stringify({
+          jsonrpc: "2.0",
+          id: 1,
+          method: "initialize",
+          params: { protocolVersion: 1 },
+        }) + "\n",
+      ),
+    )
+
+    await new Promise((resolve) => setTimeout(resolve, 500))
+
+    proc.stdin.write(
+      encoder.encode(
+        JSON.stringify({
+          jsonrpc: "2.0",
+          id: 2,
+          method: "session/new",
+          params: {
+            cwd: process.cwd(),
+            mcpServers: [],
+          },
+        }) + "\n",
+      ),
+    )
+
+    await new Promise((resolve) => setTimeout(resolve, 1000))
+
+    expect(sessionResponse).toBeTruthy()
+    expect(sessionResponse.result.sessionId).toBeTruthy()
+
+    proc.kill()
+  }, 10000)
+})