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Documentation Index

Fetch the complete documentation index at: https://docs.blend.money/llms.txt

Use this file to discover all available pages before exploring further.

Set up the credentials your app needs to talk to Blend’s SDK and API.

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SIWE domain

The SIWE domain tells Blend which domain is allowed to sign in users via wallet signatures. Without it, frontend authentication won’t work.
1

Go to credentials

Open Settings > Credentials in the portal.
2

Add your domain

Enter your app’s domain in the SIWE field. Use the format yourdomain.com or yourdomain.com:3000 for local dev. Blend normalizes this to lowercase.
3

Save and verify

Save the domain. The SIWE challenge messages will now include this domain, and wallets will show it during sign-in. Users see your domain name, not Blend’s.
Frontend SDK authentication will fail without a SIWE domain. Set this up before writing any SDK code.

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Publishable keys

Every account type gets its own publishable key. This key identifies your account type in frontend SDK calls. It’s safe to include in client-side code. Publishable keys look like pk_live_ followed by 64 hex characters. You’ll find them on the account type detail page under Settings. Pass the publishable key when you create the SDK:
sdk-init.ts
import { BlendSdk } from "@blend-money/fe";

const sdk = new BlendSdk({
  publishableKey: "pk_live_a1b2c3d4e5f6...",
  paymasterUrl: getPimlicoPaymasterUrl("your-pimlico-key"),
});
Each account type has a different publishable key. If you have multiple account types (for example, a conservative and an aggressive product), you’ll use a different key for each.

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API keys

API keys authenticate server-to-server calls. They’re secrets - never expose them in frontend code or version control.
1

Create an API key

Go to Settings > Credentials and click Create API Key. Give it a name you’ll recognize (like “production-server” or “staging”).
2

Copy the secret

The full secret is shown once. Copy it and store it in your server’s environment variables. The key looks like sk_live_ followed by a long random string.
You won’t see this secret again. If you lose it, create a new key and deactivate the old one.
3

Use it in your server SDK

Pass the API key when you create the server SDK:
server-init.ts
import { BlendServerSdk } from "@blend-money/node";

const sdk = new BlendServerSdk({
  apiKey: process.env.BLEND_API_KEY,
  accountTypeId: "savings-usdc",
});

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Key rotation

Rotate keys when team members leave, when a key may have been exposed, or on a regular schedule. Publishable keys can’t be rotated independently. They’re tied to the account type. If you need a new publishable key, contact Blend support. API keys can be rotated in the portal. Create a new key, update your server, then deactivate the old one. You can have multiple active API keys during the transition. Signing key rotation invalidates all active SDK sessions. Every signed-in user will need to sign in again. The portal limits this to 3 rotations per hour. Only rotate the signing key if you suspect it’s been compromised.

Make your first deposit

Use your new credentials to make a deposit in under 30 minutes.

Portal operations

Manage flow plans, team members, and audit logs day-to-day.
Last modified on May 7, 2026