Developer Docs

EsperWorks API

A REST API for integrating EsperWorks invoicing, contracts, and payments into your own applications. All responses are JSON. All requests must be authenticated with an API key.

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

Quickstart

Generate an API key from Dashboard → Developer API, then make your first request:

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

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

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 proposals.

Payments

List and simulate payments.

Expenses

Log and retrieve expenses.

Webhooks

Receive real-time event notifications.

SDK & Libraries

Official client libraries.

Key concepts

Scoped keys, each API key grants access only to the modules you select (e.g. invoices:read, contracts:read). See Authentication.
Business-scoped data, all data returned is scoped to the business that owns the API key. You cannot access another business's data.
Pagination, list endpoints return paginated results. Pass ?page=2&per_page=20 to navigate.
Rate limits, 120 requests per minute per API key. See Errors & Rate Limits.