Connecting and calling

A connection is how your app reaches a database, a mail server or a provider's API.

Your app reaches an outside service through a connection, a named entry under connections: in app.jadpo that says which package to use.

Providers often send values in odd forms: a date as Unix seconds, a number as text, money as a whole number of pence.

Some jobs need several calls that each change something at a provider, in order: create a customer, attach a card, start a subscription.

Your app can call another Jadpo app's API through a package made from that app's OpenAPI document, exactly, with nothing to correct by hand.

Use a grant when your app acts at another service for each of its users or organisations: a user's Google Calendar, an organisation's Xero, a Slack workspace install.

Signing in proves to your app who a person is.

In jadpo dev, every call to a provider is faked by default, so nothing leaves your machine and you need no credential.

In jadpo test, every package has a generated fake, so tests never call a provider.

This is the detail behind Connecting in app.jadpo: which keys a connection to a package takes and needs, and what jadpo check writes about the hosts it reaches.

This is the detail behind Calling: which keys an operation takes, how its input is sent, who may call it, whether it may be sent again, and how its answer is classified and read.

This is the detail behind Decoding and Calling: the encodings a provider's fields can be sent in, a package's own decoders, which fields are decoded, and how retry: and timed_out: work.

This is the detail behind Tests and fakes and Provider calls in development: what a fake answers, how a script is used, and what the call log keeps.

Every call that leaves your app's process, to a capability or to a provider, goes through one entry point in the runtime: the seam.