Supabase client with Secret Key is not compatible with local development

[sapphire008]

When developing locally, I created a supabase admin client with the Secret Key from supabase status

const SUPABASE_URL = "http://127.0.0.1:54321";
const SUPABASE_SECRET_KEY = "<local secret key>" // TODO

const supabase = createClient<Database>(SUPABASE_URL, SUPABASE_SECRET_KEY, {
 auth: {
 autoRefreshToken: false,
 persistSession: false
 }
});

and tried to add some mock users with supabase.auth.admin.createUser, I got the following error message:

❌ Failed to connect to Supabase: invalid JWT: unable to parse or verify signature, token is malformed: token contains an invalid number of segments

However, if I change the to the old Service Role Key (which no longer prints in version 2.51.0), this works just fine.

Minimally reproducible example:
test-supabase-local.zip

index.ts

#!/usr/bin/env tsx

import { createClient, User } from '@supabase/supabase-js';
import { Database } from './database.js';

// Configuration for local Supabase development
const SUPABASE_URL = "http://127.0.0.1:54321";
const SUPABASE_SECRET_KEY = "sb_secret_N7UND0UgjKTVK-Uodkm0Hg_xSvEMPvz"

// Create Supabase client with service role key for admin operations
const supabase = createClient<Database>(SUPABASE_URL, SUPABASE_SECRET_KEY, {
 auth: {
 autoRefreshToken: false,
 persistSession: false
 }
});

// Test users to insert
const testUsers = [
 {
 email: 'test1@example.com',
 password: 'TestPassword123!',
 user_metadata: {
 full_name: 'Test User One',
 username: 'testuser1'
 }
 },
 {
 email: 'test2@example.com',
 password: 'TestPassword123!',
 user_metadata: {
 full_name: 'Test User Two',
 username: 'testuser2'
 }
 },
 {
 email: 'test3@example.com',
 password: 'TestPassword123!',
 user_metadata: {
 full_name: 'Test User Three',
 username: 'testuser3'
 }
 }
];

async function insertTestUsers() {
 console.log('🚀 Starting test user insertion...');
 console.log(`📍 Supabase URL: ${SUPABASE_URL}`);
 
 for (const [index, userData] of testUsers.entries()) {
 try {
 console.log(`\n👤 Creating user ${index + 1}: ${userData.email}`);
 
 // Use admin.createUser for creating users with passwords
 const { data, error } = await supabase.auth.admin.createUser({
 email: userData.email,
 password: userData.password,
 user_metadata: userData.user_metadata,
 email_confirm: true // Auto-confirm email for testing
 });

 if (error) {
 console.error(`❌ Failed to create user ${userData.email}:`, error.message);
 continue;
 }

 if (data.user) {
 console.log(`✅ Successfully created user: ${userData.email}`);
 console.log(` User ID: ${data.user.id}`);
 console.log(` Email confirmed: ${data.user.email_confirmed_at ? 'Yes' : 'No'}`);
 }

 } catch (error) {
 console.error(`💥 Unexpected error creating user ${userData.email}:`, error);
 }
 }

 console.log('\n🎉 Test user insertion completed!');
}

async function listExistingUsers() {
 try {
 console.log('\n📋 Listing existing users...');
 
 const { data, error } = await supabase.auth.admin.listUsers();
 
 if (error) {
 console.error('❌ Failed to list users:', error.message);
 return;
 }

 console.log(`Found ${data.users.length} users:`);
 data.users.forEach((user: User, index: number) => {
 console.log(` ${index + 1}. ${user.email} (ID: ${user.id})`);
 });

 } catch (error) {
 console.error('💥 Unexpected error listing users:', error);
 }
}

async function main() {
 console.log('🔧 Supabase Test User Insertion Script');
 console.log('=====================================');

 // Check if we can connect to Supabase
 try {
 const { data, error } = await supabase.auth.admin.listUsers({ page: 1, perPage: 1 });
 if (error) {
 console.error('❌ Failed to connect to Supabase:', error.message);
 console.log('\n💡 Make sure:');
 console.log(' 1. Supabase is running locally (supabase start)');
 console.log(' 2. VITE_SUPABASE_URL is set correctly');
 console.log(' 3. SUPABASE_SERVICE_ROLE_KEY is set correctly');
 process.exit(1);
 }
 console.log('✅ Successfully connected to Supabase');
 } catch (error) {
 console.error('💥 Connection error:', error);
 process.exit(1);
 }

 // List existing users first
 await listExistingUsers();

 // Insert test users
 await insertTestUsers();

 // List users again to show the results
 await listExistingUsers();
}

// Run the script
if (import.meta.url === `file://${process.argv[1]}`) {
 main().catch(console.error);
}

• I also tried using Python client and got the same error.
• I am on Supabase CLI 2.51.0 which is the latest version at the time of writing.
• I have tried to delete everything and reinstall but it didn't make a difference.
• In the previous thread (currently locked) #29260, local development compatibility has been fixed in a previous release, but I am not sure it specifically address the case I mentioned above.
• Is there any settings that I need to configure to allow the server to accept the new secret key?

[sapphire008]

Linking original discussion thread: https://github.com/orgs/supabase/discussions/39605. Please let me know if this is the appropriate place to open this issue or help me migrate it to an appropriate place.

[rottbers]

Running into the same issue, old local service role key works fine but not the new secret key

[Hallidayo]

Hi all, Is this happening for you on cli or self-hosted?

[matleh]

For me, it's in the local dev environment.

Is there anything I can do to help resolve this issue?

[sapphire008]

@Hallidayo this is on cli, local dev enrichment.

[aantti]

@sweatybridge

[Hallidayo]

Transferred over from the supabase/supabase repo.

[sweatybridge]

Can you try the latest cli release? I believe it's fixed by #4489

npx supabase@latest start

[obigroup]

I'm encountering this issue locally with Supabase CLI v2.72.0.
My setup has gotrue issuing ES256 tokens for users, but internal service tokens (e.g., for Edge Function workers) remain HS256.

The Problem

The Edge Runtime crashes with:
TypeError: Key for the ES256 algorithm must be of type CryptoKey. Received an instance of Uint8Array

This happens because the runtime defaults to initializing with the symmetric JWT_SECRET (Uint8Array), but receives an ES256 token.

Failed Attempt: Explicit signing_keys.json

I tried to fix this by explicitly configuring signing_keys.json in config.toml to provide the proper ES256 JWK.

1. ES256 Only: If I provide only the ES256 key, user auth works, but internal services verification fails (e.g., database webhooks, cron jobs) because they use the default HS256 service key, which is no longer in the keyring (replaced by the JSON file).
2. Mixed Keys (ES256 + HS256): I attempted to include both keys in signing_keys.json to support both users and services.

   [
    { "alg": "HS256", "k": "...", ... },
    { "alg": "ES256", ... }
   ]
   

Result: The CLI refuses to start with the error:

failed to decode signing keys: failed to parse response body: must be one of [RS256 ES256]

Conclusion
It seems seemingly impossible to configure a "Mixed Environment" locally via signing_keys.json because the CLI validator rejects HS256 keys in that file. Currently, the only workaround is to disable verify_jwt in
config.toml and manually verify tokens inside the Edge Function code.

[oscadev]

so, is this getting fixed? Still happening

[Pjaijai]

Still happening after upgrading to lates cli

[aantti]

Also #4726 🤔