51114: Twilsock: Invalid access token header

Twilio rejected the Access Token used to authenticate a client connection because the token header is invalid. This error usually means the token is malformed, signed incorrectly, or not encoded as a valid JSON Web Token.

• The value sent as the Access Token is not a valid JWT
• The token header is not valid Base64URL-encoded JSON
• The token is missing a required header value such as alg or typ
• The token was altered, truncated, or corrupted before it was sent to Twilio
• Your application generated the token with the wrong library or with incompatible signing settings
• The request is sending a different credential instead of a Twilio Access Token

• Generate a new Twilio Access Token using an official Twilio helper library
• Verify that the token contains three dot-separated JWT segments for header, payload, and signature
• Decode the token and confirm the header is valid JSON and includes expected values such as alg and typ
• Confirm that your application signs the token with the correct API Key and API Key Secret for your Twilio account
• Make sure the token is passed to the client exactly as generated, without added whitespace, truncation, or URL encoding issues
• If you create tokens manually, compare your implementation against the Twilio Access Token format used for client-side SDK authentication
• Test the token structure with a JWT inspection tool before sending it to Twilio

• Access Tokens
• Identity and Access Management