We currently support OTP via SMS as the authentication means for signature. You can define the participant’s phone number when configuring your transaction.
You need to pass two arguments to specify a participant’s mobile number in a transaction:
- 
    phone_number: allows you to define the participant’s mobile number. Expected format is E.164 ([+][country code][phone number including area code]).
- 
    phone_numer_type: allows you to define the type of the participant’s mobile number, among:- 
        suggestion: you give Universign or the signer the authorization to use a different phone number that might be more appropriate.
- 
        flex_prerequisite: you give Universign or the signer the authorization to use a different phone number only for advanced signatures (we will always use the phone number defined on your side if the signature islevel1.).
- 
        prerequisite: you don’t give Universign or the signer the authorization to use a different phone number.
 
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In other words, Universign will always use the number you defined if you passed flex_prerequisite as a phone_number_type and:
- you requested a level1signature.
- you requested an advanced signature and the participant already has a certificate linked to the number you defined.
- you requested an advanced signature and the participant does not have a certificate yet but agrees to use the number you suggested.
Universign will always use the number you defined also if you passed prerequisite as phone_number_type, no matter what the signature level is.
However, we may use a different phone number to authenticate the signer if:
- you passed flex_prerequisiteas aphone_number_typeand:- you requested an advanced signature and the participant already has a certificate linked to a different phone number than the one you passed.
- you requested an advanced signature and the participant does not have a certificate yet but prefers to use a different number than the one you suggested.
 
- you passed suggestionas aphone_number_type.
Set mobile phone number as a suggestion
Send a request to POST /v1/transactions/{transaction_id}/participants and pass the participant email, the phone number in the phone_number argument as well as suggestion in the phone_number_type argument:
curl
https://api.universign.com/v1/transactions/tx_AWo949MOq0JE/participants \
-d [email protected] \
-d phone_number=+33623456789 \
-d phone_number_type=suggestion
Set mobile phone number as a flex prerequisite
Send a request to POST /v1/transactions/{transaction_id}/participants and pass the participant email, the phone number in the phone_number argument as well as flex_prerequisite in the phone_number_type argument:
curl
https://api.universign.com/v1/transactions/{transaction_id}/participants \
-d [email protected] \
-d phone_number=+33623456789 \
-d phone_number_type=flex_prerequisite
Set mobile phone number as a prerequisite
Send a request to POST /v1/transactions/{transaction_id}/participants and pass the participant email, the phone number in the phone_number argument as well as prerequisite in the phone_number_type argument:
curl
https://api.universign.com/v1/transactions/tx_AWo949MOq0JE/participants \
-d [email protected] \
-d phone_number=+33623456789 \
-d phone_number_type=prerequisite
Note that if you don’t pass a phone_number_type, default value is suggestion.
