Developer Documentation

EsperWorks API

A powerful REST API for programmatically integrating invoicing, contracts, payments and client records into your own applications. All responses are standard JSON and requests are authenticated via scoped API keys.

Production Base URL: https://api.tryesperworks.com/api/v1

Quickstart

Generate an API key from your Developer Portal, then make your first ping request:

curl https://api.tryesperworks.com/api/v1/ping \
  -H "Authorization: Bearer ew_live_xxxxxxxxxxxxxxxxxxxx"

A successful ping response returns your business name, key name, environment and authorized scopes.

API Resources

Quickstart

First API call in under 2 minutes.

Clients

Create and manage client records.

Invoices

Create, send and track invoices.

Contracts

Read contracts and their status.

Payments

List and simulate payments.

Expenses

Log and retrieve expenses.

Webhooks

Receive real-time event notifications.

SDK & Libraries

Official client libraries.

Key Concepts & Architecture

Granular Scoped Keys: Each API key grants access only to the modules and actions you select (e.g. invoices:read, contracts:create). See Authentication.
Strict Business Isolation: All returned data is isolated strictly to the authorized business tenant. Cross-tenant access is rejected with a 403 Forbidden.
Standard Pagination: List endpoints return paginated metadata. Use query parameters ?page=1&per_page=20 to navigate result sets.
Rate Limits & Reliability: 120 requests per minute per API key. See Errors & Rate Limits.