API Keys and Access Tokens

Access Tokens are short-lived tokens that you use to authenticate Twilio Client SDKs like Voice , Conversations, Sync and Video, and Twilio Live.

You create them on your server to verify a user’s identity and grant access to client API features. All tokens have a limited lifetime, configurable up to 24 hours. However, a best practice is to generate Access Tokens for the shortest amount of time feasible for your application.

Contents

• Anatomy of an Access Token
• How to create Access Tokens
  • Conversations
  • Voice
  • Video
  • Sync
  • Twilio Live (PlaybackGrant)
• Managing Access Token lifecycle

Anatomy of an Access Token

Each Access Token is a JSON Web Token (JWT), an encoded JSON object with three parts: the header, the payload, and the signature. The following is an example Access Token generated for Conversations.

eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiIsImN0eSI6InR3aWxpby1mcGE7dj0xIn0.eyJqdGkiOiJTS3h4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4LTE0NTA0NzExNDciLCJpc3MiOiJTS3h4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4Iiwic3ViIjoiQUN4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eCIsIm5iZiI6MTQ1MDQ3MTE0NywiZXhwIjoxNDUwNDc0NzQ3LCJncmFudHMiOnsiaWRlbnRpdHkiOiJ1c2VyQGV4YW1wbGUuY29tIiwiaXBfbWVzc2FnaW5nIjp7InNlcnZpY2Vfc2lkIjoiSVN4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eCIsImVuZHBvaW50X2lkIjoiSGlwRmxvd1NsYWNrRG9ja1JDOnVzZXJAZXhhbXBsZS5jb206c29tZWlvc2RldmljZSJ9fX0.IHx8KeH1acIfwnd8EIin3QBGPbfnF-yVnSFp5NpQJi0

If you inspect it with the debugger at jwt.io, you can further explore its content.

Header

{
  "typ": "JWT",
  "alg": "HS256",
  "cty": "twilio-fpa;v=1" 
}

The header section encodes the format of the token:

• typ is the type of token. Its value must be "JWT".
• alg is the algorithm used to encode the token. Its value must be "HS256".
• cty is the content-type and encodes the version of the Access Token. Its value must be "twilio-fpa;v=1".

Payload

{
  "jti": "SKxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx-1450471147",
  "iss": "SKxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
  "sub": "ACxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx",
  "iat": 1450471147,
  "nbf": 1450471147,
  "exp": 1450474747,
  "grants": {
    "identity": "user_name",
    "chat": {
      "service_sid": "ISxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
    }
  }
}

The payload section describes the authorization granted:

• jti is a unique identifier for the token. Your application can choose this identifier. The default helper library implementation includes the SID of the API key used to generate the token, and a unique random string.
• iss is the issuer — the API key containing the secret used to sign the token.
• sub is the SID of the Twilio Account to which access is scoped.
• iat is the timestamp at which the token was issued.
• nbf is an optional timestamp, before which the token will NOT be accepted.
• exp is the timestamp at which the token will expire. Tokens have a maximum age of 24 hours.
• grants is the list of permissions that the token grants. Grant properties and values will depend on the Twilio product and the needs of your specific use case.(See the Grants section below for more information.)

Signature

The signature section is a signed hash that serves to prove the authenticity of the token. It is the result of hashing the JWT header and payload together with your API key secret, which should only be known to your application and Twilio.

How to create Access Tokens

Twilio Access Tokens are based on the JSON Web Token standard.

You can use one of Twilio's Helper Libraries to create Access Tokens quickly and programmatically.

Step 1: Find your Account SID

Every Access Token requires your Account SID, which you can find in your Twilio Console. This is how the AccessToken will tie a user's activity to a specific Twilio account.

Step 2: Create an API Key and Secret

Next, you need to create an API key. You can create API keys from the Twilio Console or with the REST API.

When you create the API key, you’ll be shown the key’s secret, which is used to sign the Access Token. For security, you will only be shown the secret at this time, so you need to store it with the key’s SID in a secure location for the next step.

Step 3: Generate an Access Token

Now use the information gathered in steps 1 and 2 to generate an Access Token using a Twilio Helper Library.

When creating an Access Token, you must provide:

• Your Twilio Account SID
• The API key SID and API key secret from step 2

You can also optionally provide any of the following JWT configuration values.

Each Twilio product will also require at least one "grant", which will provide product-specific abilities to the user associated with an Access Token.

Use a Helper Library to create Access Tokens

Below are code samples for creating Access Tokens with Twilio Helper Libraries. Click on a product below to jump to the related code samples.

• Conversations
• Voice
• Video
• Sync
• Twilio Live (PlaybackGrant)

The payload of a decoded Voice AccessToken will look something like the following:

{
  "jti": "SKxxxx...-1643993631",
  "grants": {
    "identity": "alice",
    "voice": {
      "incoming": {
        "allow": true
      },
      "outgoing": {
        "application_sid": "APxxxx...",
        "params": { 
          "param1": "value1"
        }
      },
      "push_credential_sid": "CRxxxx...", 
      "endpoint_id": "..."
    }
  },
  "iat": 1643993631,
  "exp": 1643997231,
  "iss": "SKxxxx...",
  "sub": "ACxxxx..."
}

Step 4: Authenticate

Now you’re ready to use your token. For client-side SDKs like Conversations, Voice, and Video, you will need to get the stringified token to your client-side code via Ajax or some other means.

Refer to the Identity and Access Tokens guides in the product documentation for Video, Conversations, Sync for more details.

Managing the lifecycle of Access Tokens

Your can use API keys to manage the lifecycle of Access Tokens.

Since each Access Token was created using an API Key, you can delete the API key to revoke all of the Access Tokens related to that API Key.