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Exac for developers

Mexican invoicing and CFDI infrastructure for developers and AI agents

Issue invoices, read stored fiscal data, and run Mexican business workflows through REST or MCP using one organization-scoped contract. SAT synchronization is managed inside subscribed Exac workspaces. Production API/MCP certification requires prepaid wallet credit from the first timbre; Gratis's ten monthly CFDIs apply only to the web app. Sandbox certification is free.

REST APIIntegrate Exac from any backend with explicit schemas, organization-scoped credentials, and predictable responses.Explore the APIMCP serverGive compatible AI agents permission-aware access to the same trusted business operations.Connect an agent

Production and sandbox

Organization API keys are bound to one environment. Sandbox keys use the operations marked “Production and sandbox” in the API reference against isolated test data. Production-only operations and MCP remain unavailable in sandbox. Credentials are rejected outside their assigned environment.
Quickstart

Set up a sandbox API key, make your first request, and follow the REST and MCP workflows.

The contract is ready to build on

The OpenAPI 3.1 artifact is generated from the same operation ledger as the REST runtime and is checked against generated TypeScript and Python clients.