Add GitHub Copilot ACP runtime

README.md

@@ -25,7 +25,7 @@ NeverWrite is an agentic markdown workspace for people who work with a local vau
 
 - **Write in the format that fits.** Edit Markdown, Mermaid, CSV, text/code files, PDFs, images, and Excalidraw concept maps in the same workspace.
 - **Navigate connected knowledge.** Follow wikilinks, backlinks, tags, advanced search, bookmarks, and 2D or 3D graph views.
-- **Work with your preferred agent.** Run Codex, Claude, Grok, Kilo, or OpenCode sessions with attachments, saved transcripts, and local history.
+- **Work with your preferred agent.** Run Codex, Claude, GitHub Copilot, Grok, Kilo, or OpenCode sessions with attachments, saved transcripts, and local history.
 - **Review AI changes deliberately.** Inspect tracked edits inline, in chat, or in a dedicated review tab, then keep or reject complete files and individual hunks.
 - **Capture the web into your vault.** Use the companion browser extension to clip pages, selections, or URLs directly to the desktop app.
 

apps/desktop/native-backend/src/runtime_catalog.rs

@@ -1,6 +1,6 @@
 use neverwrite_ai::{
     custom_runtimes::CustomAcpRuntimeDefinition, CLAUDE_RUNTIME_ID, CODEX_RUNTIME_ID,
-    GROK_RUNTIME_ID, KILO_RUNTIME_ID, OPENCODE_RUNTIME_ID,
+    COPILOT_RUNTIME_ID, GROK_RUNTIME_ID, KILO_RUNTIME_ID, OPENCODE_RUNTIME_ID,
 };
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -180,6 +180,7 @@ impl<'a> RuntimeCatalogView<'a> {
 }
 
 const NO_ACP_ARGS: &[&str] = &[];
+const COPILOT_ACP_ARGS: &[&str] = &["--acp"];
 const GROK_ACP_ARGS: &[&str] = &["--no-auto-update", "agent", "stdio"];
 const SHELL_ACP_ARGS: &[&str] = &["acp"];
 
@@ -204,6 +205,16 @@ const BUILT_IN_RUNTIME_DEFINITIONS: &[BuiltInRuntimeDefinition] = &[
         acp_protocol: AcpProtocolFlavor::Current,
         supports_native_resume: false,
     },
+    BuiltInRuntimeDefinition {
+        id: COPILOT_RUNTIME_ID,
+        name: "GitHub Copilot",
+        description: "GitHub Copilot CLI running as a native ACP agent.",
+        default_executable: "copilot",
+        bin_env_var: "NEVERWRITE_COPILOT_ACP_BIN",
+        acp_args: COPILOT_ACP_ARGS,
+        acp_protocol: AcpProtocolFlavor::Current,
+        supports_native_resume: false,
+    },
     BuiltInRuntimeDefinition {
         id: GROK_RUNTIME_ID,
         name: "Grok",
@@ -275,6 +286,7 @@ mod tests {
             [
                 CODEX_RUNTIME_ID,
                 CLAUDE_RUNTIME_ID,
+                COPILOT_RUNTIME_ID,
                 GROK_RUNTIME_ID,
                 KILO_RUNTIME_ID,
                 OPENCODE_RUNTIME_ID,
@@ -321,6 +333,12 @@ mod tests {
                 Some("NEVERWRITE_CLAUDE_ACP_BIN"),
                 Vec::new(),
             ),
+            (
+                COPILOT_RUNTIME_ID,
+                "copilot",
+                Some("NEVERWRITE_COPILOT_ACP_BIN"),
+                vec!["--acp".to_string()],
+            ),
             (
                 GROK_RUNTIME_ID,
                 "grok",
@@ -353,7 +371,7 @@ mod tests {
         let catalog = RUNTIME_CATALOG.with_custom(&custom);
         let definitions = catalog.definitions().collect::<Vec<_>>();
 
-        assert_eq!(definitions.len(), 6);
+        assert_eq!(definitions.len(), 7);
         let custom = catalog.definition(&custom[0].id).unwrap();
         assert!(custom.is_custom());
         assert_eq!(custom.name(), "Local agent");

apps/desktop/scripts/smoke-electron-ai-runtime.mjs

@@ -224,6 +224,7 @@ if (customCapturePath) {
     pid: process.pid
   }));
 }
+const isCopilot = process.argv.includes("--acp");
 function send(message) {
   process.stdout.write(JSON.stringify({ jsonrpc: "2.0", ...message }) + "\\n");
 }
@@ -234,6 +235,20 @@ function option(id, name) {
   return { value: id, name };
 }
 function configOptions(mode = "default") {
+  if (isCopilot) {
+    return [
+      {
+        id: "mode", name: "Mode", category: "mode", type: "select",
+        currentValue: "https://agentclientprotocol.com/protocol/session-modes#agent",
+        options: [
+          option("https://agentclientprotocol.com/protocol/session-modes#agent", "Agent"),
+          option("https://agentclientprotocol.com/protocol/session-modes#plan", "Plan"),
+          option("https://agentclientprotocol.com/protocol/session-modes#autopilot", "Autopilot")
+        ]
+      },
+      { id: "allow_all", name: "Allow All", category: "other", type: "select", currentValue: "off", options: [option("off", "Off"), option("on", "On")] }
+    ];
+  }
   return [
     {
       id: "mode",
@@ -314,8 +329,12 @@ createInterface({ input: process.stdin }).on("line", (line) => {
         availableModels: [{ modelId: "auto", name: "Auto" }]
       },
       modes: {
-        currentModeId: "default",
-        availableModes: [
+        currentModeId: isCopilot ? "https://agentclientprotocol.com/protocol/session-modes#agent" : "default",
+        availableModes: isCopilot ? [
+          { id: "https://agentclientprotocol.com/protocol/session-modes#agent", name: "Agent" },
+          { id: "https://agentclientprotocol.com/protocol/session-modes#plan", name: "Plan" },
+          { id: "https://agentclientprotocol.com/protocol/session-modes#autopilot", name: "Autopilot" }
+        ] : [
           { id: "default", name: "Default" },
           { id: "review", name: "Review" }
         ]
@@ -644,6 +663,7 @@ async function main() {
     for (const runtimeId of [
       "codex-acp",
       "claude-acp",
+      "copilot-acp",
       "grok-acp",
       "kilo-acp",
       "opencode-acp",
@@ -1295,6 +1315,27 @@ async function main() {
       "real ACP stream completion",
     );
 
+    const copilotSetup = await client.invoke("ai_update_setup", {
+      runtimeId: "copilot-acp",
+      input: { custom_binary_path: fakeAcpPath },
+    });
+    assert(copilotSetup.binary_ready === true, "Copilot should resolve the fake ACP binary");
+    const copilotSession = await client.invoke("ai_create_session", {
+      input: { runtime_id: "copilot-acp", additional_roots: null },
+      vaultPath,
+    });
+    assert(
+      copilotSession.modes.some((mode) => mode.name === "Agent") &&
+        copilotSession.modes.some((mode) => mode.name === "Plan") &&
+        copilotSession.modes.some((mode) => mode.name === "Autopilot"),
+      "Copilot ACP modes should preserve their negotiated IDs",
+    );
+    const allowAll = copilotSession.config_options.find((option) => option.id === "allow_all");
+    assert(allowAll?.value === "off", "Copilot Allow All must remain disabled by default");
+    await client.invoke("ai_set_config_option", {
+      input: { session_id: copilotSession.session_id, option_id: "allow_all", value: "on" },
+    });
+
     await fs.writeFile(fakeAcpRequestLogPath, "");
     await client.invoke("ai_update_setup", {
       runtimeId: "claude-acp",

apps/desktop/src/features/ai/store/chatStore.ts

@@ -2038,6 +2038,7 @@ function isAuthenticationErrorMessage(
 
     const normalized = message.trim().toLowerCase();
     const isOpenCodeRuntime = runtimeId === "opencode-acp";
+    const isCopilotRuntime = runtimeId === "copilot-acp";
     const isOpenCodeAuthGuidance =
         normalized.includes("run opencode auth login") ||
         normalized.includes("use /connect") ||
@@ -2046,12 +2047,21 @@ function isAuthenticationErrorMessage(
                 normalized.includes("no provider configured") ||
                 normalized.includes("unauthorized") ||
                 normalized.includes("401")));
+    const isCopilotAuthGuidance =
+        normalized.includes("run copilot login") ||
+        normalized.includes("copilot login") ||
+        (isCopilotRuntime &&
+            (normalized.includes("login required") ||
+                normalized.includes("not authenticated") ||
+                normalized.includes("unauthorized") ||
+                normalized.includes("401")));
 
     return (
         normalized.includes("auth_required") ||
         normalized.includes("authentication required") ||
         normalized.includes("auth required") ||
         isOpenCodeAuthGuidance ||
+        isCopilotAuthGuidance ||
         normalized.includes("you were signed out") ||
         normalized.includes("reconnect in ai setup") ||
         normalized.includes("reconnect codex") ||

apps/desktop/src/features/ai/utils/authMethods.test.ts

@@ -18,6 +18,9 @@ describe("authMethods", () => {
         expect(
             isIntegratedTerminalAuthMethod("opencode-acp", "opencode-login"),
         ).toBe(true);
+        expect(
+            isIntegratedTerminalAuthMethod("copilot-acp", "copilot-login"),
+        ).toBe(true);
     });
 
     it("rejects terminal auth methods for the wrong runtime", () => {
@@ -40,6 +43,7 @@ describe("authMethods", () => {
         expect(isIntegratedTerminalAuthMethodId("grok-login")).toBe(true);
         expect(isIntegratedTerminalAuthMethodId("kilo-login")).toBe(true);
         expect(isIntegratedTerminalAuthMethodId("opencode-login")).toBe(true);
+        expect(isIntegratedTerminalAuthMethodId("copilot-login")).toBe(true);
         expect(isIntegratedTerminalAuthMethodId("openai-api-key")).toBe(false);
     });
 });

apps/desktop/src/features/ai/utils/authMethods.ts

@@ -32,6 +32,10 @@ export function isIntegratedTerminalAuthMethod(
         return methodId === "opencode-login";
     }
 
+    if (runtimeId === "copilot-acp") {
+        return methodId === "copilot-login";
+    }
+
     return false;
 }
 
@@ -40,6 +44,7 @@ export function isIntegratedTerminalAuthMethodId(methodId?: string) {
         isClaudeTerminalAuthMethodId(methodId) ||
         methodId === "grok-login" ||
         methodId === "kilo-login" ||
-        methodId === "opencode-login"
+        methodId === "opencode-login" ||
+        methodId === "copilot-login"
     );
 }

apps/desktop/src/features/ai/utils/runtimeMetadata.test.ts

@@ -24,6 +24,11 @@ describe("runtimeMetadata", () => {
                     name: "Grok",
                     company: "xAI",
                 }),
+                expect.objectContaining({
+                    id: "copilot-acp",
+                    name: "GitHub Copilot",
+                    company: "GitHub",
+                }),
             ]),
         );
     });
@@ -60,6 +65,12 @@ describe("runtimeMetadata", () => {
                         ]),
                     }),
                 }),
+                expect.objectContaining({
+                    runtime: expect.objectContaining({
+                        id: "copilot-acp",
+                        name: "GitHub Copilot ACP",
+                    }),
+                }),
             ]),
         );
     });
@@ -80,6 +91,7 @@ describe("runtimeMetadata", () => {
         expect(getRuntimeDisplayName("kilo-acp")).toBe("Kilo");
         expect(getRuntimeDisplayName("grok-acp")).toBe("Grok");
         expect(getRuntimeDisplayName("opencode-acp")).toBe("OpenCode");
+        expect(getRuntimeDisplayName("copilot-acp")).toBe("GitHub Copilot");
         expect(getRuntimeDisplayName(undefined, undefined)).toBe("Assistant");
     });
 });

apps/desktop/src/features/ai/utils/runtimeMetadata.ts

@@ -44,6 +44,13 @@ const RUNTIME_METADATA: RuntimeMetadata[] = [
             "prompt_queueing",
         ],
     },
+    {
+        id: "copilot-acp",
+        name: "GitHub Copilot",
+        company: "GitHub",
+        description: "GitHub Copilot CLI running as a native ACP agent.",
+        capabilities: ["attachments", "permissions", "plans", "terminal_output", "create_session", "prompt_queueing", "user_input"],
+    },
     {
         id: "grok-acp",
         name: "Grok",

apps/desktop/src/features/settings/AIProvidersSettings.tsx

@@ -47,6 +47,8 @@ import type {
 
 const OPENCODE_RUNTIME_ID = "opencode-acp";
 const OPENCODE_AUTH_METHOD_ID = "opencode-login";
+const COPILOT_RUNTIME_ID = "copilot-acp";
+const COPILOT_AUTH_METHOD_ID = "copilot-login";
 const GROK_RUNTIME_ID = "grok-acp";
 const CLAUDE_ACP_RUNTIME_ID = "claude-acp";
 const GOOGLE_VERTEX_METHOD_ID = "google-vertex";
@@ -161,6 +163,7 @@ function getShortMethodDesc(id: string): string {
         case "grok-login":
         case "kilo-login":
         case OPENCODE_AUTH_METHOD_ID:
+        case COPILOT_AUTH_METHOD_ID:
             return "Terminal sign-in";
         case "openai-api-key":
             return "OpenAI API key";
@@ -199,6 +202,8 @@ function getAuthHelpText(id: string): string {
             return "Opens a Kilo sign-in terminal inside the app.";
         case OPENCODE_AUTH_METHOD_ID:
             return "Use providers and credentials configured by the OpenCode CLI.";
+        case COPILOT_AUTH_METHOD_ID:
+            return "Open GitHub Copilot sign-in in an integrated terminal.";
         case "openai-api-key":
             return `Store an OpenAI API key locally for ${APP_BRAND_NAME} only.`;
         case "codex-api-key":
@@ -241,6 +246,7 @@ function getActionLabel(
     if (methodId === "grok-login") return "Open sign-in terminal";
     if (methodId === "kilo-login") return "Open sign-in terminal";
     if (methodId === OPENCODE_AUTH_METHOD_ID) return "Open sign-in terminal";
+    if (methodId === COPILOT_AUTH_METHOD_ID) return "Open sign-in terminal";
     if (isApiKeyMethod(methodId)) {
         return status.authReady && status.authMethod === methodId
             ? "Replace key"
@@ -251,11 +257,13 @@ function getActionLabel(
 }
 
 function getSecondaryAuthActionLabel(status: AIRuntimeSetupStatus): string {
-    return status.runtimeId === OPENCODE_RUNTIME_ID ? "Disconnect" : "Log Out";
+    return [OPENCODE_RUNTIME_ID, COPILOT_RUNTIME_ID].includes(status.runtimeId)
+        ? "Disconnect"
+        : "Log Out";
 }
 
 function getLogoutErrorFallback(runtimeId: string): string {
-    return runtimeId === OPENCODE_RUNTIME_ID
+    return [OPENCODE_RUNTIME_ID, COPILOT_RUNTIME_ID].includes(runtimeId)
         ? "Failed to disconnect."
         : "Failed to log out.";
 }
@@ -313,7 +321,7 @@ function setSecretPatch(value: string): AISecretPatch {
 }
 
 function supportsRuntimeBinaryOverride(runtimeId: string): boolean {
-    return runtimeId === OPENCODE_RUNTIME_ID || runtimeId === GROK_RUNTIME_ID;
+    return [OPENCODE_RUNTIME_ID, GROK_RUNTIME_ID, COPILOT_RUNTIME_ID].includes(runtimeId);
 }
 
 function getRuntimeBinaryPlaceholder(runtimeId: string): string {
@@ -323,6 +331,9 @@ function getRuntimeBinaryPlaceholder(runtimeId: string): string {
     if (runtimeId === GROK_RUNTIME_ID) {
         return "Custom Grok runtime path, for example grok";
     }
+    if (runtimeId === COPILOT_RUNTIME_ID) {
+        return "Custom GitHub Copilot runtime path, for example copilot";
+    }
     return "Custom runtime path";
 }
 
@@ -333,6 +344,9 @@ function getRuntimeBinaryHelpText(runtimeId: string): string {
     if (runtimeId === GROK_RUNTIME_ID) {
         return "Leave empty to use grok from PATH.";
     }
+    if (runtimeId === COPILOT_RUNTIME_ID) {
+        return "Leave empty to use copilot from PATH.";
+    }
     return "Leave empty to use the bundled runtime or PATH.";
 }
 
@@ -420,6 +434,10 @@ function getProviderSearchValues(
         provider.id === GROK_RUNTIME_ID
             ? "NEVERWRITE_GROK_ACP_BIN"
             : undefined,
+        provider.id === COPILOT_RUNTIME_ID ? "copilot acp --acp" : undefined,
+        provider.id === COPILOT_RUNTIME_ID
+            ? "NEVERWRITE_COPILOT_ACP_BIN"
+            : undefined,
         getMethodDisplayName(setupStatus),
         error,
         ...(setupStatus

crates/ai/src/domain.rs

@@ -4,6 +4,7 @@ use serde::{Deserialize, Serialize};
 
 pub const CODEX_RUNTIME_ID: &str = "codex-acp";
 pub const CLAUDE_RUNTIME_ID: &str = "claude-acp";
+pub const COPILOT_RUNTIME_ID: &str = "copilot-acp";
 pub const GROK_RUNTIME_ID: &str = "grok-acp";
 pub const KILO_RUNTIME_ID: &str = "kilo-acp";
 pub const OPENCODE_RUNTIME_ID: &str = "opencode-acp";

crates/index/tests/integration.rs

@@ -883,7 +883,10 @@ fn reindex_updates_status() {
         "Note A",
         serde_json::json!({ "status": "draft", "type": "article" }),
     )]);
-    assert_eq!(index.metadata[&NoteId("a".into())].status.as_deref(), Some("draft"));
+    assert_eq!(
+        index.metadata[&NoteId("a".into())].status.as_deref(),
+        Some("draft")
+    );
 
     index.reindex_note(make_note_with_frontmatter(
         "a",
@@ -903,7 +906,10 @@ fn reindex_clears_removed_status() {
         "Note A",
         serde_json::json!({ "status": "draft" }),
     )]);
-    assert_eq!(index.metadata[&NoteId("a".into())].status.as_deref(), Some("draft"));
+    assert_eq!(
+        index.metadata[&NoteId("a".into())].status.as_deref(),
+        Some("draft")
+    );
 
     index.reindex_note(make_note_with_frontmatter(
         "a",