Built-in variables

A node passes built-in variables into every script it runs with POST /v1/run. A script reads them like any variable. They’re read-only, and their names are reserved. See Built-in variables in the RequestScript docs for the language rules. Stellarium passes one built-in: jwt.

jwt

jwt is the decoded run token the run was made with, as an object. The node has already verified it: it is signed by the operator, unexpired and addressed to this node.

Field	Type	Value
`iss`	`string`	Always `"stellarium"`
`sub`	`string`	The API client’s ID (`cli_...`)
`aud`	`string`	The public key of the node running the script
`org`	`string`	The ID of the organization the API client belongs to, which pays for the run
`iat`	`int32`	When the token was issued, in Unix seconds
`exp`	`int32`	When the token expires, in Unix seconds
`jti`	`string`	The token’s unique ID

For a run made with the node’s API_KEY, there is no token, and jwt is null:

request Caller {
    if (jwt == null) {
        return "api key"
    }
    return jwt.sub
}

Passing the caller to a function

Use jwt to tell a resource function who is calling, for example to keep a quota per API client:

request CheckQuota {
    const quotas: com.example.Quotas

    return quotas.remaining(clientId: jwt.sub, organizationId: jwt.org)
}

A function on another node receives these values as ordinary parameters, which the caller can set to anything. Only the node running the script verified the token. Don’t treat a clientId parameter as proof of identity in a function another node calls.

Rules

jwt can’t be changed. jwt = ..., jwt.sub = ..., and changes through a variable that holds it, fail the script.
You can’t declare a variable named jwt.

A script that breaks either rule fails like any other script that errors at runtime: the node answers 422 with "error": "Script failed", and a billed run is charged for the tokens it executed.

Getting Started

Concepts

Running a node

Standard Library

Inference

Community

jwt

Passing the caller to a function

Rules

​jwt

​Passing the caller to a function

​Rules

jwt

Passing the caller to a function

Rules