Agent Skills: Grove Auth Integration

Grove Auth Integration

Add Heartwood authentication to a Grove property — from client registration through production deployment.

When to Activate

• User says "add auth to this project" or "wire up Heartwood"
• User is building a new Grove property that needs login
• User needs to register a new OAuth client with Heartwood
• User explicitly calls /grove-auth-integration
• User mentions needing sign-in, protected routes, or session validation
• User says "integrate GroveAuth" or "add login"

Key URLs

| Service | URL | Purpose | | --------------- | ------------------------------- | -------------------------------- | | Login UI | https://heartwood.grove.place | Where users authenticate | | API | https://auth-api.grove.place | Token exchange, verify, sessions | | D1 Database | groveauth (via wrangler) | Client registration |

The Pipeline

Identify → Register Client → Configure Secrets → Write Code → Wire Wrangler → Test

Error Handling in Auth Flows: Auth errors MUST use the AUTH_ERRORS Signpost catalog — never bare redirect with ad-hoc error strings.

import {
	AUTH_ERRORS,
	getAuthError,
	logAuthError,
	buildErrorParams,
} from "@autumnsgrove/lattice/heartwood";

// In callback — map OAuth error to structured code
if (errorParam) {
	const authError = getAuthError(errorParam);
	logAuthError(authError, { path: "/auth/callback" });
	redirect(302, `/login?${buildErrorParams(authError)}`);
}

See AgentUsage/error_handling.md for the full Signpost reference.

Type-Safe Error Handling in Catch Blocks: Always use Rootwork type guards in catch blocks instead of manual property checks. Import isRedirect() and isHttpError() from @autumnsgrove/lattice/server:

import { isRedirect, isHttpError } from "@autumnsgrove/lattice/server";

try {
	// ... auth flow code
} catch (err) {
	if (isRedirect(err)) throw err; // Re-throw SvelteKit redirects
	if (isHttpError(err)) {
		// Handle HTTP errors with proper status and message
	}
	redirect(302, "/?error=auth_failed");
}

Step 1: Identify the Integration

Ask the user (or determine from context):

1. Project name — The Cloudflare Pages/Workers project name
2. Client ID — A simple slug (e.g., grove-plant, grove-domains, arbor-admin)
3. Site URL — Production URL (e.g., https://plant.grove.place)
4. Callback path — Usually /auth/callback
5. Project type — SvelteKit Pages (most common), Workers, or other
6. Session approach — OAuth tokens (standard) or SessionDO (faster, same-account only)

Step 2: Register the OAuth Client

2a. Generate client secret

CLIENT_SECRET=$(openssl rand -base64 32)
echo "Client Secret: $CLIENT_SECRET"

Save this value — you'll need it for both the client secrets AND the database hash.

2b. Generate base64url hash

CRITICAL: Heartwood uses base64url encoding — dashes (-), underscores (_), NO padding (=).

CLIENT_SECRET_HASH=$(echo -n "$CLIENT_SECRET" | openssl dgst -sha256 -binary | base64 | tr '+/' '-_' | tr -d '=')
echo "Secret Hash: $CLIENT_SECRET_HASH"

| Format | Example | Correct? | | ------------- | ---------------------------------- | -------- | | base64url | Sdgtaokie8-H7GKw-tn0S_6XNSh1rdv | YES | | base64 | Sdgtaokie8+H7GKw+tn0S/6XNSh1rdv= | NO | | hex | 49d82d6a89227bcf87ec62b0... | NO |

2c. Insert into Heartwood database

wrangler d1 execute groveauth --remote --command="
INSERT INTO clients (id, name, client_id, client_secret_hash, redirect_uris, allowed_origins)
VALUES (
  '$(uuidgen | tr '[:upper:]' '[:lower:]')',
  'DISPLAY_NAME',
  'CLIENT_ID',
  'BASE64URL_HASH',
  '[\"https://SITE_URL/auth/callback\", \"http://localhost:5173/auth/callback\"]',
  '[\"https://SITE_URL\", \"http://localhost:5173\"]'
)
ON CONFLICT(client_id) DO UPDATE SET
  client_secret_hash = excluded.client_secret_hash,
  redirect_uris = excluded.redirect_uris,
  allowed_origins = excluded.allowed_origins;
"

Always include localhost in redirect_uris and allowed_origins for development.

Step 3: Configure Secrets on the Client

For Pages projects (SvelteKit):

echo "CLIENT_ID" | wrangler pages secret put GROVEAUTH_CLIENT_ID --project PROJECT_NAME
echo "CLIENT_SECRET" | wrangler pages secret put GROVEAUTH_CLIENT_SECRET --project PROJECT_NAME
echo "https://SITE_URL/auth/callback" | wrangler pages secret put GROVEAUTH_REDIRECT_URI --project PROJECT_NAME
echo "https://auth-api.grove.place" | wrangler pages secret put GROVEAUTH_URL --project PROJECT_NAME

For Workers projects:

cd worker-directory
echo "CLIENT_ID" | wrangler secret put GROVEAUTH_CLIENT_ID
echo "CLIENT_SECRET" | wrangler secret put GROVEAUTH_CLIENT_SECRET

Step 4: Write the Auth Code (SvelteKit)

Create these files in the SvelteKit project:

4a. Login initiation route: src/routes/auth/+server.ts

/**
 * OAuth Initiation - Start Heartwood OAuth flow
 * Redirects to GroveAuth with PKCE parameters.
 */
import { redirect } from "@sveltejs/kit";
import type { RequestHandler } from "./$types";

function generateRandomString(length: number): string {
	const charset = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-._~";
	const randomValues = crypto.getRandomValues(new Uint8Array(length));
	return Array.from(randomValues, (v) => charset[v % charset.length]).join("");
}

async function generatePKCE(): Promise<{
	verifier: string;
	challenge: string;
}> {
	const verifier = generateRandomString(64);
	const encoder = new TextEncoder();
	const data = encoder.encode(verifier);
	const hash = await crypto.subtle.digest("SHA-256", data);
	const challenge = btoa(String.fromCharCode(...new Uint8Array(hash)))
		.replace(/\+/g, "-")
		.replace(/\//g, "_")
		.replace(/=/g, "");
	return { verifier, challenge };
}

export const GET: RequestHandler = async ({ url, cookies, platform }) => {
	const env = platform?.env as Record<string, string> | undefined;
	const authBaseUrl = env?.GROVEAUTH_URL || "https://auth-api.grove.place";
	const clientId = env?.GROVEAUTH_CLIENT_ID || "YOUR_CLIENT_ID";
	const appBaseUrl = env?.PUBLIC_APP_URL || "https://YOUR_SITE_URL";
	const redirectUri = `${appBaseUrl}/auth/callback`;

	const { verifier, challenge } = await generatePKCE();
	const state = generateRandomString(32);

	const isProduction = url.hostname !== "localhost" && url.hostname !== "127.0.0.1";
	const cookieOptions = {
		path: "/",
		httpOnly: true,
		secure: isProduction,
		sameSite: "lax" as const,
		maxAge: 60 * 10, // 10 minutes
	};

	cookies.set("auth_state", state, cookieOptions);
	cookies.set("auth_code_verifier", verifier, cookieOptions);

	const authUrl = new URL(`${authBaseUrl}/login`);
	authUrl.searchParams.set("client_id", clientId);
	authUrl.searchParams.set("redirect_uri", redirectUri);
	authUrl.searchParams.set("response_type", "code");
	authUrl.searchParams.set("scope", "openid profile email");
	authUrl.searchParams.set("state", state);
	authUrl.searchParams.set("code_challenge", challenge);
	authUrl.searchParams.set("code_challenge_method", "S256");

	redirect(302, authUrl.toString());
};

4b. Callback handler: src/routes/auth/callback/+server.ts

/**
 * OAuth Callback - Handle Heartwood OAuth response
 * Exchanges authorization code for tokens and creates session.
 */
import { redirect } from "@sveltejs/kit";
import { isRedirect } from "@autumnsgrove/lattice/server";
import type { RequestHandler } from "./$types";

export const GET: RequestHandler = async ({ url, cookies, platform }) => {
	const code = url.searchParams.get("code");
	const state = url.searchParams.get("state");
	const errorParam = url.searchParams.get("error");

	if (errorParam) {
		redirect(302, `/?error=${encodeURIComponent(errorParam)}`);
	}

	// Validate state (CSRF protection)
	const savedState = cookies.get("auth_state");
	if (!state || state !== savedState) {
		redirect(302, "/?error=invalid_state");
	}

	// Get PKCE verifier
	const codeVerifier = cookies.get("auth_code_verifier");
	if (!codeVerifier || !code) {
		redirect(302, "/?error=missing_credentials");
	}

	// Clear auth cookies immediately
	cookies.delete("auth_state", { path: "/" });
	cookies.delete("auth_code_verifier", { path: "/" });

	const env = platform?.env as Record<string, string> | undefined;
	const authBaseUrl = env?.GROVEAUTH_URL || "https://auth-api.grove.place";
	const clientId = env?.GROVEAUTH_CLIENT_ID || "YOUR_CLIENT_ID";
	const clientSecret = env?.GROVEAUTH_CLIENT_SECRET || "";
	const appBaseUrl = env?.PUBLIC_APP_URL || "https://YOUR_SITE_URL";
	const redirectUri = `${appBaseUrl}/auth/callback`;

	try {
		// Exchange code for tokens
		const tokenResponse = await fetch(`${authBaseUrl}/token`, {
			method: "POST",
			headers: { "Content-Type": "application/x-www-form-urlencoded" },
			body: new URLSearchParams({
				grant_type: "authorization_code",
				code,
				redirect_uri: redirectUri,
				client_id: clientId,
				client_secret: clientSecret,
				code_verifier: codeVerifier,
			}),
		});

		if (!tokenResponse.ok) {
			redirect(302, "/?error=token_exchange_failed");
		}

		const tokens = (await tokenResponse.json()) as {
			access_token: string;
			refresh_token?: string;
			expires_in?: number;
		};

		// Fetch user info
		const userinfoResponse = await fetch(`${authBaseUrl}/userinfo`, {
			headers: { Authorization: `Bearer ${tokens.access_token}` },
		});

		if (!userinfoResponse.ok) {
			redirect(302, "/?error=userinfo_failed");
		}

		const userinfo = (await userinfoResponse.json()) as {
			sub?: string;
			id?: string;
			email: string;
			name?: string;
			email_verified?: boolean;
		};

		const userId = userinfo.sub || userinfo.id;
		const email = userinfo.email;

		if (!userId || !email) {
			redirect(302, "/?error=incomplete_profile");
		}

		// Set session cookies
		const isProduction = url.hostname !== "localhost" && url.hostname !== "127.0.0.1";
		const cookieOptions = {
			path: "/",
			httpOnly: true,
			secure: isProduction,
			sameSite: "lax" as const,
			maxAge: 60 * 60 * 24 * 7, // 7 days
		};

		cookies.set("access_token", tokens.access_token, {
			...cookieOptions,
			maxAge: tokens.expires_in || 3600,
		});

		if (tokens.refresh_token) {
			cookies.set("refresh_token", tokens.refresh_token, {
				...cookieOptions,
				maxAge: 60 * 60 * 24 * 30, // 30 days
			});
		}

		// TODO: Create local session or onboarding record as needed
		// This varies by property — adapt to your app's needs

		redirect(302, "/dashboard"); // Or wherever authenticated users go
	} catch (err) {
		// Type-safe error handling with Rootwork type guards
		if (isRedirect(err)) throw err; // Re-throw SvelteKit redirects
		redirect(302, "/?error=auth_failed");
	}
};

4c. Session validation hook: src/hooks.server.ts

Choose ONE approach:

Option A: Token verification (works cross-account)

import type { Handle } from "@sveltejs/kit";

export const handle: Handle = async ({ event, resolve }) => {
	const accessToken = event.cookies.get("access_token");

	if (accessToken) {
		try {
			const env = event.platform?.env as Record<string, string> | undefined;
			const authBaseUrl = env?.GROVEAUTH_URL || "https://auth-api.grove.place";

			const response = await fetch(`${authBaseUrl}/verify`, {
				headers: { Authorization: `Bearer ${accessToken}` },
			});

			if (response.ok) {
				const result = await response.json();
				if (result.active) {
					event.locals.user = {
						id: result.sub,
						email: result.email,
						name: result.name,
					};
				}
			}
		} catch {
			// Token invalid or expired — user remains unauthenticated
		}
	}

	return resolve(event);
};

Option B: SessionDO validation (faster, same Cloudflare account only)

Requires a service binding in wrangler.toml (see Step 5).

import type { Handle } from "@sveltejs/kit";

export const handle: Handle = async ({ event, resolve }) => {
	const cookieHeader = event.request.headers.get("Cookie") || "";

	// Only validate if grove_session or access_token cookie exists
	if (cookieHeader.includes("grove_session") || cookieHeader.includes("access_token")) {
		try {
			const env = event.platform?.env as any;

			// Use service binding for sub-100ms validation
			const response = await env.AUTH.fetch("https://auth-api.grove.place/session/validate", {
				method: "POST",
				headers: { Cookie: cookieHeader },
			});

			if (response.ok) {
				const { valid, user } = await response.json();
				if (valid && user) {
					event.locals.user = {
						id: user.id,
						email: user.email,
						name: user.name,
					};
				}
			}
		} catch {
			// Session invalid — user remains unauthenticated
		}
	}

	return resolve(event);
};

4d. Type definitions: src/app.d.ts

declare global {
	namespace App {
		interface Locals {
			user?: {
				id: string;
				email: string;
				name?: string | null;
			};
		}
		interface Platform {
			env?: {
				GROVEAUTH_URL?: string;
				GROVEAUTH_CLIENT_ID?: string;
				GROVEAUTH_CLIENT_SECRET?: string;
				PUBLIC_APP_URL?: string;
				AUTH?: Fetcher; // Service binding (Option B only)
				DB?: D1Database;
				[key: string]: unknown;
			};
		}
	}
}

export {};

4e. Protected route layout: src/routes/admin/+layout.server.ts

import { redirect } from "@sveltejs/kit";
import type { LayoutServerLoad } from "./$types";

export const load: LayoutServerLoad = async ({ locals }) => {
	if (!locals.user) {
		redirect(302, "/auth");
	}
	return { user: locals.user };
};

4f. Logout route: src/routes/auth/logout/+server.ts

import { redirect } from "@sveltejs/kit";
import type { RequestHandler } from "./$types";

export const POST: RequestHandler = async ({ cookies, platform }) => {
	const accessToken = cookies.get("access_token");

	if (accessToken) {
		const env = platform?.env as Record<string, string> | undefined;
		const authBaseUrl = env?.GROVEAUTH_URL || "https://auth-api.grove.place";

		// Revoke token at Heartwood
		await fetch(`${authBaseUrl}/logout`, {
			method: "POST",
			headers: { Authorization: `Bearer ${accessToken}` },
		}).catch(() => {}); // Best-effort
	}

	// Clear all auth cookies
	cookies.delete("access_token", { path: "/" });
	cookies.delete("refresh_token", { path: "/" });

	redirect(302, "/");
};

Step 5: Wire Up wrangler.toml

Add these to the project's wrangler.toml:

# Heartwood (GroveAuth) - Service Binding for fast session validation
# Only works for projects in the same Cloudflare account
[[services]]
binding = "AUTH"
service = "groveauth"

# Secrets (configured via wrangler pages secret / Cloudflare Dashboard):
# - GROVEAUTH_URL = https://auth-api.grove.place
# - GROVEAUTH_CLIENT_ID = your-client-id
# - GROVEAUTH_CLIENT_SECRET = (generated in Step 2)
# - GROVEAUTH_REDIRECT_URI = https://yoursite.com/auth/callback
# - PUBLIC_APP_URL = https://yoursite.com

Step 6: Test the Flow

1. Deploy the project (or run locally with pnpm dev)
2. Navigate to /auth — should redirect to Heartwood login
3. Authenticate with Google (or other configured provider)
4. Should redirect back to /auth/callback
5. Should set cookies and redirect to protected area
6. Visit /admin (protected) — should show authenticated content
7. Logout via POST to /auth/logout — should clear session

Token Lifecycle

| Token | Lifetime | Storage | Refresh | | ------------- | ---------- | --------------- | ----------------- | | Access Token | 1 hour | httpOnly cookie | Via refresh token | | Refresh Token | 30 days | httpOnly cookie | Re-login required | | PKCE Verifier | 10 minutes | httpOnly cookie | Single-use | | State | 10 minutes | httpOnly cookie | Single-use |

Session Validation Approaches

| Approach | Speed | Requirement | Use When | | ----------------------------------- | ------------ | --------------- | ------------------------------------- | | Token Verify (/verify) | ~50-150ms | Network call | Cross-account, external services | | SessionDO (/session/validate) | ~5-20ms | Service binding | Same Cloudflare account (recommended) | | Cookie SSO (.grove.place) | ~0ms (local) | Same domain | All *.grove.place properties |

For Grove properties on .grove.place subdomains, the grove_session cookie is shared automatically across all subdomains.

Checklist

Before going live, verify:

• [ ] Client registered in Heartwood D1 (clients table)
• [ ] Secret hash uses base64url encoding (dashes, underscores, no padding)
• [ ] redirect_uris includes BOTH production AND localhost
• [ ] allowed_origins includes BOTH production AND localhost
• [ ] Secrets set via wrangler pages secret put (NOT in wrangler.toml!)
• [ ] PKCE flow generates fresh verifier per login attempt
• [ ] State parameter validated in callback (CSRF protection)
• [ ] Auth cookies cleared immediately after code exchange
• [ ] Protected routes check locals.user and redirect if missing
• [ ] Logout revokes token at Heartwood AND clears local cookies
• [ ] Cookie secure flag is true in production, false in localhost

Troubleshooting

"Invalid client credentials" (401)

Almost always a hash format mismatch. Regenerate with the exact base64url command in Step 2b.

"Invalid redirect_uri"

The callback URL must EXACTLY match what's in the redirect_uris JSON array in the database. Check trailing slashes, protocol, and port.

"Invalid state" on callback

The state cookie expired (10min TTL) or was lost. Check:

• Cookie domain matches the callback domain
• No redirect loops between domains consuming the cookie early

"Code verifier required"

The PKCE verifier cookie wasn't sent with the callback request. Ensure:

• Cookie path is / (not /auth)
• Cookie domain matches callback domain
• No third-party cookie blocking

Session validation returns 401

• Token may have expired (1hr lifetime) — implement refresh logic
• Service binding may not be configured — check wrangler.toml
• Cookie domain mismatch — .grove.place cookies only work on subdomains

"CORS error" on auth API calls

Add your domain to allowed_origins in the Heartwood clients table.

Anti-Patterns

Don't do these:

• Don't store client_secret in wrangler.toml or source code
• Don't skip PKCE — it's required, not optional
• Don't reuse state or verifier values across login attempts
• Don't store tokens in localStorage (XSS-vulnerable)
• Don't skip state validation in the callback (enables CSRF)
• Don't hard-code auth-api.grove.place — use the env var for flexibility
• Don't forget localhost in redirect_uris (you'll need it for dev)

Authentication should be invisible until it's needed. Let Heartwood handle the complexity.