diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 2a97e33b..e316e96d 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -79,6 +79,7 @@ After runtime replacement, use `runtimeHost.session` as the new live session and
 
 ### Fixed
 
+- Fixed startup resource loading to reuse the initial `ResourceLoader` for the first runtime, so extensions are not loaded twice before session startup and `session_start` handlers still fire for singleton-style extensions ([#2766](https://github.com/badlogic/pi-mono/issues/2766))
 - Fixed theme `export` colors to resolve theme variables the same way as `colors`, so `/export` HTML backgrounds now honor entries like `pageBg: "base"` instead of requiring inline hex values ([#2707](https://github.com/badlogic/pi-mono/issues/2707))
 
 ## [0.64.0] - 2026-03-29
diff --git a/packages/coding-agent/src/core/agent-session-runtime.ts b/packages/coding-agent/src/core/agent-session-runtime.ts
index 4f2fd8ce..6b59335a 100644
--- a/packages/coding-agent/src/core/agent-session-runtime.ts
+++ b/packages/coding-agent/src/core/agent-session-runtime.ts
@@ -53,6 +53,8 @@ export interface CreateAgentSessionRuntimeOptions {
 	cwd: string;
 	/** Optional preselected session manager. If omitted, normal session resolution applies. */
 	sessionManager?: SessionManager;
+	/** Optional preloaded resource loader to reuse instead of creating and reloading one. */
+	resourceLoader?: ResourceLoader;
 	/** Optional session_start metadata to emit when the runtime binds extensions. */
 	sessionStartEvent?: SessionStartEvent;
 }
@@ -86,15 +88,18 @@ export async function createAgentSessionRuntime(
 	const settingsManager = SettingsManager.create(cwd, agentDir);
 	const modelRegistry = ModelRegistry.create(authStorage, join(agentDir, "models.json"));
 	const resourceLoader =
-		typeof bootstrap.resourceLoader === "function"
+		options.resourceLoader ??
+		(typeof bootstrap.resourceLoader === "function"
 			? await bootstrap.resourceLoader(cwd, agentDir)
 			: new DefaultResourceLoader({
 					...(bootstrap.resourceLoader ?? {}),
 					cwd,
 					agentDir,
 					settingsManager,
-				});
-	await resourceLoader.reload();
+				}));
+	if (!options.resourceLoader) {
+		await resourceLoader.reload();
+	}
 
 	const extensionsResult = resourceLoader.getExtensions();
 	for (const { name, config } of extensionsResult.runtime.pendingProviderRegistrations) {
diff --git a/packages/coding-agent/src/main.ts b/packages/coding-agent/src/main.ts
index d3fdb88b..64ab41c8 100644
--- a/packages/coding-agent/src/main.ts
+++ b/packages/coding-agent/src/main.ts
@@ -873,6 +873,7 @@ export async function main(args: string[]) {
 	const runtime = await createAgentSessionRuntime(runtimeBootstrap, {
 		cwd: sessionManager?.getCwd() ?? cwd,
 		sessionManager,
+		resourceLoader,
 	});
 	if (process.cwd() !== runtime.cwd) {
 		process.chdir(runtime.cwd);