negative zero Review

2021 March 25

[messaging] [phone] [review] [tech] [xmpp] is a service that provides USA and Canada phone numbers for use with Cheogram, which in turn provides and voice calls (over SIP) and SMS/MMS (over XMPP) services. These are part of, a family of projects which describes itself as "a vision of freedom-respecting and interoperable communication using open standards, including projects that generalize phone numbers so they're easier to use from computers, tablets, and any other device." Phone numbers from other countries can be acquired through Vonage and used with Cheogram, but this requires more setup.

JMP is currently in a beta period, which will last "until at least July 2021", and not all features are available at this time. However, it does provide the basic essential text and voice features.



How It Works

JMP relies on two protocols: XMPP for SMS/MMS (and voicemail) and SIP for voice calls. You need an existing XMPP account, and you will be provided a SIP account (although you can use your own if you want). You must add the XMPP transport in your XMPP client. Then you can text other phone numbers by sending XMPP messages to +[10-digit phone number], and you can call them by dialing the 10-digit phone number in your SIP client. I have tested sending files via HTTP upload, and they are successfully delivered as MMS messages.

If you're not logged in with your SIP client when someone calls your number, they can leave a voicemail, which will be delivered to you as an audio file via XMPP and optionally may be automatically transcribed for you. Text and media messages to your phone number are likewise delivered as XMPP messages.

Pricing and Payment Options

There is a free trial which lasts for 30 days and includes 300 outgoing SMS/MMS messages and 30 minutes of voice calls. (Incoming text/picture messages are unlimited.)

A paid account currently costs 2.99 USD per month, or 34.99 USD per year. Once the beta period is over, there will be multiple plans.

The JMP system can currently automate payments via PayPal or Bitcoin. To pay via other methods, one must contact the team. Payments in Bitcoin may be for 1 or 3 years of service, but not monthly (presumably because Bitcoin transaction fees are prohibitively expensive).

During the beta period, paid accounts provide unlimited SMS/MMS messages and 120 minutes of voice calls per month.

After the beta period, the $2.99 per month/$34.99 per year plan will have a limit on outgoing messages, and other plans will be available. Incoming SMS/MMS messages will still be unlimited.


JMP is free software, licensed under the AGPLv3+. Additionally, most parts of the website work without JavaScript altogether.

Since JMP is still in beta, some features are still not automated, so you may need to contact support to make changes to your account, and so on.

You will also need SIP and XMPP clients to use JMP.


I like it. For a fairly low price, it enables me to have a phone number I can list on forms that require it without having to use an actual phone, and it makes receiving messages convenient since XMPP is already my primary messaging platform. I also like that it's a free software project.

While having a limited number of voice call minutes can feel constraining, 120 minutes per month is approximately 120 minutes more than I spend on the phone in a standard month, so I don't worry too much about running out.

If you use your phone a lot, this probably won't be sufficient as a replacement for you (though it might be a nice option for a second number, if that's something you need or want). It's great for me, as simply having a phone number reserved for me is about the extent of my telephone needs.