Fetching User Token

Using the “state” from step 10, “code verifier” from step 12, and the “authorization code” from step 9, you need to make a network call to Truecaller’s backend so as to fetch the access token :

POST https://oauth-account-noneu.truecaller.com/v1/token

Headers

Name	Type	Description
Content-Type*	application/x-www-form-urlencoded
	String

Request Body

Name	Type	Description
grant_type*	"authorization_code"	// hardcoded value
	String
client_id*	<YOUR_CLIENT_ID>
code*	<USER_AUTHORISATION_CODE>	Authorisation code from TcOAuthData callback from step 9
code_verifier*	<YOUR_CODE_VERIFIER>	From step 12

200: OK Success

{ "access_token": "some-access-token", "expires_in": 3600, "token_type": "Bearer" }

400: Bad Request If grant type is not supported

{ "error": unsupported_grant_type, "error_description": Grant type <requested-grant-type> not supported }

403: Forbidden If client id is invalid

{ "error": invalid_client, "error_description": "Invalid client Id" }

500: Internal Server Error Unexpected error on server side

{ "error": server_error }

400: Bad Request Some of the parameters are empty in the request

{ "error": invalid_request, "error_description": Empty parameter(s) in request }

403: Forbidden Valid grant type but not allowed for client

{ "error": invalid_grant }

403: Forbidden Invalid auth code provided

{ "error": access_denied }

403: Forbidden Invalid/expired auth code in provided

{ "error": invalid_grant, "error_description": "Invalid authorization code" }

403: Forbidden Invalid/expired code verifier is provided

{ "error": invalid_grant, "error_description": "Invalid code verifier" }

429: Too Many Requests If the number of requests exceed the allowed limit

{ "error": too_many_requests }

503: Service Unavailable Resource unavailable due to server side issue

{ "error": temporarily_unavailable }

Sample cURL request :

curl --location --request POST 'https://oauth-account-noneu.truecaller.com/v1/token' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'grant_type=authorization_code' \
--data-urlencode 'client_id=<<your-client-id>>' \
--data-urlencode 'code=<<authorization_code>>' \
--data-urlencode 'code_verifier=<<your-code-verifier>>'