diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index d5468403f..9b180d591 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed new sessions intermittently ignoring the saved default model, or warning that no models are available, when it belongs to an extension-registered native provider with a stored credential ([#9962](https://github.com/earendil-works/pi/issues/9962)).
+
 ## [0.99.1] - 2026-09-29
 
 ### New Features
diff --git a/packages/coding-agent/src/core/model-runtime.ts b/packages/coding-agent/src/core/model-runtime.ts
index 47663aed6..7edd44048 100644
--- a/packages/coding-agent/src/core/model-runtime.ts
+++ b/packages/coding-agent/src/core/model-runtime.ts
@@ -885,9 +885,37 @@ export class ModelRuntime implements Models {
 		this.nativeExtensionProviders.set(provider.id, provider);
 		this.recomposeProvider(provider.id);
 		this.updateModelSnapshot();
+		this.markProvisionallyConfigured(
+			provider.id,
+			configuredRequestAuthStatus(this.config.getProvider(provider.id), undefined),
+			provider.auth.oauth && !provider.auth.apiKey ? "oauth" : "api_key",
+		);
 		void this.refresh({ allowNetwork: false });
 	}
 
+	/**
+	 * Mark a newly registered provider as configured when it has a stored credential or a configured
+	 * API key. Availability checks run asynchronously, and callers such as initial model selection
+	 * read the snapshot before they finish. The next availability pass replaces this entry.
+	 */
+	private markProvisionallyConfigured(
+		providerId: string,
+		configuredStatus: AuthStatus | undefined,
+		type: AuthType,
+	): void {
+		if (!this.snapshot.storedProviders.has(providerId) && !configuredStatus?.configured) return;
+		const configuredProviders = new Set(this.snapshot.configuredProviders).add(providerId);
+		const auth = new Map(this.snapshot.auth);
+		// Never clobber a real check result.
+		if (!auth.get(providerId)) auth.set(providerId, { type, source: "configured provider" });
+		this.snapshot = {
+			...this.snapshot,
+			auth,
+			configuredProviders,
+			available: this.snapshot.all.filter((model) => configuredProviders.has(model.provider)),
+		};
+	}
+
 	registerProvider(providerId: string, config: ProviderConfigInput): void {
 		// Validate the incoming registration on its own, like the legacy registry:
 		// a broken re-registration must throw without touching the stored config.
@@ -903,26 +931,11 @@ export class ModelRuntime implements Models {
 		this.extensionProviders.set(providerId, effective);
 		this.recomposeProvider(providerId);
 		this.updateModelSnapshot();
-		if (
-			this.snapshot.storedProviders.has(providerId) ||
-			configuredRequestAuthStatus(this.config.getProvider(providerId), effective)?.configured
-		) {
-			const configuredProviders = new Set(this.snapshot.configuredProviders).add(providerId);
-			const auth = new Map(this.snapshot.auth);
-			// Provisional entry until the async refresh lands; never clobber a real check result.
-			if (!auth.get(providerId)) {
-				auth.set(providerId, {
-					type: effective.oauth && !effective.apiKey ? "oauth" : "api_key",
-					source: "configured provider",
-				});
-			}
-			this.snapshot = {
-				...this.snapshot,
-				auth,
-				configuredProviders,
-				available: this.snapshot.all.filter((model) => configuredProviders.has(model.provider)),
-			};
-		}
+		this.markProvisionallyConfigured(
+			providerId,
+			configuredRequestAuthStatus(this.config.getProvider(providerId), effective),
+			effective.oauth && !effective.apiKey ? "oauth" : "api_key",
+		);
 		void this.refresh({ allowNetwork: false });
 	}
 
diff --git a/packages/coding-agent/test/model-runtime-modify-models-compat.test.ts b/packages/coding-agent/test/model-runtime-modify-models-compat.test.ts
index f30005131..db7d89515 100644
--- a/packages/coding-agent/test/model-runtime-modify-models-compat.test.ts
+++ b/packages/coding-agent/test/model-runtime-modify-models-compat.test.ts
@@ -91,6 +91,50 @@ describe("extension provider model lifecycle", () => {
 		expect(registry.getProvider("extension-native")).toBeUndefined();
 	});
 
+	// Regression for #9962: initial model selection reads the snapshot before the async refresh finishes.
+	it("marks a native provider with a stored credential as configured when it registers", async () => {
+		const runtime = await ModelRuntime.create({
+			credentials: AuthStorage.inMemory({
+				"extension-native": {
+					type: "oauth",
+					access: "access",
+					refresh: "refresh",
+					expires: Date.now() + 3_600_000,
+				},
+			}),
+			modelsStore: new InMemoryModelsStore(),
+			modelsPath: null,
+			allowModelNetwork: false,
+		});
+		const nativeModel = { ...model("native"), provider: "extension-native" };
+		const unused = () => {
+			throw new Error("unused");
+		};
+		const provider: Provider = {
+			id: "extension-native",
+			name: "Extension Native",
+			auth: {
+				oauth: {
+					name: "Native OAuth",
+					login: unused,
+					refresh: async (credential) => credential,
+					toAuth: async (credential) => ({ apiKey: credential.access }),
+				},
+			},
+			getModels: () => [nativeModel],
+			stream: unused,
+			streamSimple: unused,
+		};
+
+		runtime.registerNativeProvider(provider);
+
+		expect(runtime.hasConfiguredAuth("extension-native")).toBe(true);
+		expect(runtime.isUsingOAuth("extension-native")).toBe(true);
+		expect(runtime.getAvailableSnapshot().map((m) => `${m.provider}/${m.id}`)).toContain("extension-native/native");
+		await runtime.refresh({ allowNetwork: false });
+		expect(runtime.hasConfiguredAuth("extension-native")).toBe(true);
+	});
+
 	it("preserves native deferred methods through provider overlays", async () => {
 		const tempDir = mkdtempSync(join(tmpdir(), "pi-native-provider-deferred-"));
 		const modelsPath = join(tempDir, "models.json");