I'm a little bit confused about the name and scope of the project.

Is it an SPV Bitcoin wallet that runs as a daemon and is interfaced through an HTTP API? (And has the extra feature of batched transactions)
Is the API supposed to be user-facing or is it supposed to be used by yourself / an application you are developing (such as exchange, online casino, etc.)?

Because 'as a service' usually suggests that it's hosted by one entity and accessible by many others (who are then using this service). These can in turn be developers as well, or end users.
But if you host it for yourself / for your application or whatever, it doesn't really fit the classical SaaS definition.