Overview

An activity is a TypeScript file that implements one step of a workflow. Each activity exports a main function and a description string.

Anatomy

export const description = `
# Select Coverage

Selects the primary coverage to bill against.

## Input
- **context** — BillingCaseContext from fetch-context
- **coverageId** — (optional) explicit Coverage ID override

## Output
- **coverage** — the selected Coverage resource
- **selectionReason** — why this coverage was selected
- **hasCoverage** — true if a coverage was found
- **noCoverage** — true if no active coverage exists
`;

interface Input {
  context: BillingCaseContext;
  coverageId?: string;
}

interface Output {
  coverage?: Record<string, unknown>;
  selectionReason: string;
  hasCoverage: boolean;
  noCoverage: boolean;
}

export async function main(input: Input): Promise<Output> {
  // implementation
  const coverage = selectBestCoverage(input.context, input.coverageId);
  if (!coverage) {
    return { selectionReason: "no active coverage", hasCoverage: false, noCoverage: true };
  }
  return { coverage, selectionReason: "active PPO", hasCoverage: true, noCoverage: false };
}

Required exports

Two kinds of activities

Built-in activities implement generic billing logic reusable across all clients. Project-specific activities implement client-specific decisions (coverage selection strategy, custom save logic, etc.).