๐Ÿช™Access Tokens

Access tokens represent a secure and credible verification of wallet and/or token ownership that can be leveraged repeatedly without additional user interaction until expiration.

Anatomy of an Access Token

Access tokens represent a secure and credible verification of wallet and/or token ownership that can be leveraged repeatedly without additional user interaction until expiration.

{
    "walletAddress": "0xA548ac9c6f41B19175023B5f09c6E70f99cFeec8",
    "displayAddress": "ens.eth",
    "contractAddress": "0xbc4ca0eda7647a8ab7c2061c2e118a18a936f13d",
    "tokenBalance": "0.1337",
    "iat": 1649191258,
    "ext": 1649191858,
    "iss": "picketapi.com",
    "sub": "ethereum:0xA548ac9c6f41B19175023B5f09c6E70f99cFeec8",
    "aud": "53e74bdf-6e6e-4f31-b0d1-ceda189a6a25",
    "tid": "58db4a26-fbc1-4c53-8741-5d39e25f54f5",
    "ver": 1
}

Get an Access Token

Access tokens are returned after a successful auth flow, which is usually initiated by picket.login. An access token is valid until its expiration timestamp (exp). Once an access token expires, the user will have to re-login to get a new one.

Remember, an access token is a secret. Never share an access token with anyone!

Once a user is logged in, you'll get their access token as part of the response from picket.login. If you are using a Picket client-side SDK, the user's access token will be saved to the browser's local storage and can be access as part of the SDK's auth state.

Examples

Get the access token from the auth state once the user is logged in

const { accessToken } = await picket.authState()

Use an Access Token

Access tokens are used in JWT-based authentication to allow an application to access an API. To include an access token (JWT) in a request, send it as a Bearer Token in the HTTP Authorization header.

curl my-offchain-nft-api.com -H 'Authorization: Bearer eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.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.nI6E5yzn3gHvw7ego37A_PkoLOLfkdrIPCjYi3XVMC6zTPSjD8-aZOB-auIW92Rgsf_NggAGiT2XXRTaEq_8hA'

Once a backend receives an access token in the authorization header, it should parse the header and validate the access token. After validating, the backend can trust that the request came from the associated wallet address!

Validate an Access Token

The simplest way to validate an access token is to leverage Picket's /auth/validate endpoint; however, you can also validate access token manually.

import Picket from "@picketapi/picket-node";

const picket = new Picket("YOUR_PROJECT_SECRET_KEY");

const accessToken = "eyJhbGciOiJFUzI1NiIsInR5cCI6IkpXVCJ9.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.nI6E5yzn3gHvw7ego37A_PkoLOLfkdrIPCjYi3XVMC6zTPSjD8-aZOB-auIW92Rgsf_NggAGiT2XXRTaEq_8hA";

try {
  // optionally include token ownership requirements as the second parameter
  const decodedAccessToken = await picket.validate(accessToken)
} catch (err) {
  console.error("invalid access token:", err);
}

Steps to Manually Validate an Access Token

This section gets into the weeds for those who want it. For the easiest and fastest way to validate JWTs, we recommend using our validate endpoint to validate JWTs server-side which handles this all for you in a single api call.

1. Perform standard JWT validation

The process for validating any JWT is as follows

  1. Check the JWT is well-formed. This can be done without knowing the encryption method or signing key

  2. Check the signature. This requires fetching the corresponding public key from Pickets' JSON Web Keys (JWKs) endpoint (/.well-known/jwks.json).

  3. Check the standard claims

    1. The issuer iss equals picketapi.com

    2. Check that the JWT hasn't expired. The expiration time exp must be later than (>) the current unix timestamp

For more details on how to do this, we recommend Auth0's documentation on this standard process.

2. Verify the audience (aud) claim

Once you performed the standard JWT validation, you'll have the decoded JWT. With the decoded JWT, you'll want to verify that the aud equals your Picket project ID. This prevents other people from using a different an access token from another Picket-powered application.

// replace with a real ID
const PICKET_PROJECT_ID = "53e74bdf-6e6e-4f31-b0d1-ceda189a6a25";

const checkClaims = (jwt) => {
  // deconstruction can be done in parameter declaration, 
  // moved here for readability
  const { iss, aud } = jwt;
  // check both fields exist
  if (!(iss && aud)) return false;
  
  return iss === "picketapi.com" && aud === PICKET_PROJECT_ID;
}

3. (Optional) Verify token ownership requirements

If this is a token-gated API, you'll need to verify the access token meets the requirements.

import BigNumber from "bignumber.js";

const isBAYCOwner = (jwt) => {
   const { contractAddress, numTokens } = jwt;

   // check both fields exist
   if (!(contractAddress && numTokens)) return false;
   
   return (
      // Bored Ape Yacht Club contract address
      contractAddress === "0xbc4ca0eda7647a8ab7c2061c2e118a18a936f13d" 
      // remember numTokens is a string!
      && BigNumber(numTokens).isGreaterThan(0) );
} 

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