KERNlang · cukas · Jun 8, 2026 · Jun 8, 2026
diff --git a/packages/cli/package.json b/packages/cli/package.json
@@ -56,7 +56,6 @@
   "dependencies": {
     "@kernlang/agon-engines": "^0.1.1",
     "@kernlang/agon-dedup": "^0.1.6",
-    "@kernlang/agon-mcp": "^0.1.6",
     "@ai-sdk/anthropic": "^3.0.67",
     "@ai-sdk/openai-compatible": "^2.0.40",
     "@kernlang/protocol": "~3.5.8",

diff --git a/packages/cli/src/generated/cesar/session.ts b/packages/cli/src/generated/cesar/session.ts
@@ -999,14 +999,20 @@ export function mcpConfigFingerprint(config: any): string {
 }
 
 /**
- * Resolve the agon-orchestration MCP server entry (packages/mcp/dist/index.js). The CLI ships as a tsup BUNDLE (chunks at packages/cli/dist/), so the old fixed '../../../../mcp/dist/index.js' relative to import.meta.url resolved to a NONEXISTENT path — the MCP server never spawned and Cesar saw zero tools (slow scraping fallback). Resolution order: (1) node module resolution of @kernlang/agon-mcp (works installed AND monorepo-via-symlink), (2) walk up to the repo root containing packages/mcp/dist/index.js (monorepo without a symlink), (3) the original relative guess as a last resort. `fromUrl` is for tests; defaults to this module's URL.
+ * Resolve the agon-orchestration MCP server entry. The CLI ships as a tsup BUNDLE that ALSO emits the MCP server to <cli-dist>/mcp/index.js (see tsup.config.ts), so the published install is self-contained — no @kernlang/agon-mcp npm dependency. Resolution order: (0) the bundled sibling <cli-dist>/mcp/index.js (the published, self-contained path), (1) node module resolution of @kernlang/agon-mcp (monorepo-via-symlink / legacy installs), (2) walk up to the repo root containing packages/mcp/dist/index.js (monorepo without a symlink), (3) the original relative guess as a last resort. `fromUrl` is for tests; defaults to this module's URL.
  */
 // @kern-source: session:961
 export function resolveAgonMcpServerPath(fromUrl?: string): string {
   const raw = fromUrl ?? import.meta.url;
   // Accept either a file: URL (normal) or a bare path (defensive): fileURLToPath
   // throws ERR_INVALID_URL_SCHEME on a bare path, so normalise first.
   const url = raw.startsWith('file:') ? raw : pathToFileURL(raw).href;
+  // 0) Bundled sibling — cli's tsup build emits the MCP server to
+  //    <cli-dist>/mcp/index.js (see tsup.config.ts). This is the PUBLISHED
+  //    path: self-contained, no @kernlang/agon-mcp dependency. The importing
+  //    chunk lives in the cli dist dir, so dist/mcp/index.js sits beside it.
+  const bundledSibling = join(dirname(fileURLToPath(url)), 'mcp', 'index.js');
+  if (existsSync(bundledSibling)) return bundledSibling;
   // 1) Installed/published OR monorepo workspace symlink — node resolution.
   try {
     const req = createRequire(url);
@@ -1029,7 +1035,7 @@ export function resolveAgonMcpServerPath(fromUrl?: string): string {
 /**
  * Single source of truth for which backend a Cesar engine will actually use. Honours config.cesarBackend preference ('auto' | 'cli' | 'api'). Pure — no side effects beyond registry lookups. Returns backend='none' when the engine has neither a usable binary nor an API key; callers decide how to handle that.
  */
-// @kern-source: session:987
+// @kern-source: session:993
 export function resolveCesarBackend(ctx: HandlerContext, engineId?: string): { backend: 'cli'|'api'|'none', binaryPath: string, hasBinary: boolean, hasApi: boolean, engine: any } {
   const config = ctx.config;
   const cesarEngineId = engineId ?? (config as any).cesarEngine ?? config.forgeFixedStarter ?? 'claude';
@@ -1054,7 +1060,7 @@ export function resolveCesarBackend(ctx: HandlerContext, engineId?: string): { b
   return { backend: 'none', binaryPath: '', hasBinary, hasApi, engine };
 }
 
-// @kern-source: session:1013
+// @kern-source: session:1019
 export async function ensureCesarSession(ctx: HandlerContext): Promise<PersistentSession> {
   const config = ctx.config;
   const cesarEngineId = (config as any).cesarEngine ?? config.forgeFixedStarter ?? 'claude';

diff --git a/packages/cli/src/kern/cesar/session.kern b/packages/cli/src/kern/cesar/session.kern
@@ -959,12 +959,18 @@ fn name=mcpConfigFingerprint params="config:any" returns=string
   >>>
 
 fn name=resolveAgonMcpServerPath params="fromUrl?:string" returns=string export=true
-  doc "Resolve the agon-orchestration MCP server entry (packages/mcp/dist/index.js). The CLI ships as a tsup BUNDLE (chunks at packages/cli/dist/), so the old fixed '../../../../mcp/dist/index.js' relative to import.meta.url resolved to a NONEXISTENT path — the MCP server never spawned and Cesar saw zero tools (slow scraping fallback). Resolution order: (1) node module resolution of @kernlang/agon-mcp (works installed AND monorepo-via-symlink), (2) walk up to the repo root containing packages/mcp/dist/index.js (monorepo without a symlink), (3) the original relative guess as a last resort. `fromUrl` is for tests; defaults to this module's URL."
+  doc "Resolve the agon-orchestration MCP server entry. The CLI ships as a tsup BUNDLE that ALSO emits the MCP server to <cli-dist>/mcp/index.js (see tsup.config.ts), so the published install is self-contained — no @kernlang/agon-mcp npm dependency. Resolution order: (0) the bundled sibling <cli-dist>/mcp/index.js (the published, self-contained path), (1) node module resolution of @kernlang/agon-mcp (monorepo-via-symlink / legacy installs), (2) walk up to the repo root containing packages/mcp/dist/index.js (monorepo without a symlink), (3) the original relative guess as a last resort. `fromUrl` is for tests; defaults to this module's URL."
   handler <<<
     const raw = fromUrl ?? import.meta.url;
     // Accept either a file: URL (normal) or a bare path (defensive): fileURLToPath
     // throws ERR_INVALID_URL_SCHEME on a bare path, so normalise first.
     const url = raw.startsWith('file:') ? raw : pathToFileURL(raw).href;
+    // 0) Bundled sibling — cli's tsup build emits the MCP server to
+    //    <cli-dist>/mcp/index.js (see tsup.config.ts). This is the PUBLISHED
+    //    path: self-contained, no @kernlang/agon-mcp dependency. The importing
+    //    chunk lives in the cli dist dir, so dist/mcp/index.js sits beside it.
+    const bundledSibling = join(dirname(fileURLToPath(url)), 'mcp', 'index.js');
+    if (existsSync(bundledSibling)) return bundledSibling;
     // 1) Installed/published OR monorepo workspace symlink — node resolution.
     try {
       const req = createRequire(url);

diff --git a/packages/cli/tsup.config.ts b/packages/cli/tsup.config.ts
@@ -14,7 +14,12 @@ function copyEngines(outDir: string) {
 }
 
 export default defineConfig({
-  entry: ['src/index.ts'],
+  // Two entries from ONE build: the CLI itself, and the agon-orchestration MCP
+  // server (../mcp/src/index.ts) emitted to dist/mcp/index.js. Bundling the MCP
+  // server in keeps `npm i -g @kernlang/agon` self-contained — Cesar spawns the
+  // bundled copy (see resolveAgonMcpServerPath) instead of an unpublished
+  // @kernlang/agon-mcp dependency. Both entries inline agon-core and share chunks.
+  entry: { index: 'src/index.ts', 'mcp/index': '../mcp/src/index.ts' },
   format: ['esm'],
   dts: false,
   sourcemap: true,
@@ -48,5 +53,10 @@ export default defineConfig({
   },
   async onSuccess() {
     copyEngines(join(process.cwd(), 'dist'));
+    // The bundled MCP server resolves engines via <its-own-dir>/engines
+    // (resolveBuiltinEnginesDir), so it needs a copy next to dist/mcp/index.js —
+    // otherwise the spawned server starts with ZERO engines and Cesar silently
+    // loses its orchestration tools.
+    copyEngines(join(process.cwd(), 'dist', 'mcp'));
   },
 });
diff --git a/packages/mcp/package.json b/packages/mcp/package.json
@@ -1,10 +1,8 @@
 {
   "name": "@kernlang/agon-mcp",
   "version": "0.1.6",
+  "private": true,
   "type": "module",
-  "bin": {
-    "agon-mcp": "./dist/index.js"
-  },
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
   "files": [

diff --git a/packages/mcp/src/index.ts b/packages/mcp/src/index.ts
@@ -1,4 +1,9 @@
-#!/usr/bin/env node
+// NOTE: no `#!/usr/bin/env node` shebang here on purpose. This entry is bundled
+// into the cli package (cli/dist/mcp/index.js) by cli's tsup, whose `banner`
+// already prepends the shebang — a second one here lands on line 2 of the bundle
+// and is a hard SyntaxError. The server is always spawned via `node <path>`
+// (see resolveAgonMcpServerPath / the agon-orchestration mcpServer config), so it
+// never needs to be directly executable.
 // Agon Orchestration MCP Server — entry point
 // Spawned by companion engines (Codex, Gemini, OpenCode) to expose
 // Tribunal, Brainstorm, Campfire, Forge, etc. as MCP tools.