#02. Schema and fn.add

Now let's ask the server to describe itself.

#Start the demo server

telepact demo-server --port 8000

#Call fn.api_

curl -s localhost:8000/api -d '[{}, {"fn.api_": {}}]'

The response is large, so let's focus on the part that matters for fn.add:

[
  {},
  {
    "Ok_": {
      "api": [
        ...,
        {
          "///": "A function that adds two numbers.",
          "fn.add": {
            "x": "number",
            "y": "number"
          },
          "->": [
            {
              "Ok_": {
                "result": "number"
              }
            }
          ]
        },
        ...
      ]
    }
  }
]

This schema is the whole interface surface area of the server. If we can read the schema, we can discover the API without guessing.

#Call fn.add

Request:

curl -s localhost:8000/api -d '[{}, {"fn.add": {"x": 1, "y": 2}}]'

Response:

[{}, {"Ok_": {"result": 3}}]

#Internal names end with _

This is a good moment to notice a naming pattern:

• fn.ping_ and fn.api_ end with _, so they are internal

• fn.add does not end with _, so it was defined by the service author

Every Telepact server comes with stock internal definitions like fn.ping_ and fn.api_. Service authors add their own public definitions beside them.

If we want to see the internal definitions too, we can ask for them:

curl -s localhost:8000/api -d '[{}, {"fn.api_": {"includeInternal!": true}}]'

Next: 03. Data type validation