---
# System prepended metadata

title: How do I know a property is an Envelope?

---

# How do I know a property is an Envelope?

## One way, look at the JSON Schema

The property will be of type `https://api.openteams.com/json-schema/Envelope`, or it will be of type `array` with `$ref` of `https://api.openteams.com/json-schema/Envelope`.

That is:

```json
{
    "type": "https://api.openteams.com/json-schema/Envelope"
}
```

or

```json
{
    "type": "array"
    , "$ref": "https://api.openteams.com/json-schema/Envelope"
}
```

or even

```json=
{
    "type": "object"
    , "$ref": "https://api.openteams.com/json-schema/Envelope"
}
```

## How should we scaffold this until we have the ContextLookup done?

```javascript=
function getEnvelopeProperties(response) {
    // for now, fake it! Look at the json-schema uri and return the already known list of envelope properties.
}
```