zSign - 2026 Pricing, Features, Reviews & Alternatives

zSign is a cloud-based, API-first e-signature service built for developers, software teams, and AI agents that need to send, track, and manage legally binding electronic signatures without per-seat subscription costs. Operating on a prepaid envelope credit model (1 credit = 1 signed envelope, credits never expire), zSign supports ESIGN and UETA compliance with SHA-256 tamper-evident audit trails and completion certificates shipped with every finished envelope. Deployment options include a REST API over HTTPS, a web dashboard, a CLI, a Zapier integration (Beta), and a hosted MCP (Model Context Protocol) server at zsign.io/mcp exposing 29 tools covering the full envelope lifecycle.

zSign is designed for fully automated and unattended workflows. Its hosted MCP server allows AI agents (compatible with Claude, ChatGPT, Cursor, or any Streamable HTTP MCP client) to create accounts, check pricing, purchase credits programmatically via Stripe Checkout, send PDFs, track envelope status, and download sealed signed copies without human involvement. Auth is handled via Bearer API key (zs_ prefix) or OAuth 2.1, and MCP tools operate as a thin adapter over the same REST API, ensuring consistent behavior across integration methods. A draft approval flow is also available for teams that require human review before an envelope is dispatched.

For businesses requiring brand control, zSign offers a white-label plan at $49/month, covering custom logos, brand colors, badge removal, signing pages hosted on a custom domain, and email delivery from a verified sender domain, with 100 envelope credits included monthly. Template links allow reusable signature collection without code. Webhook support, embed SDKs, and a free tier (3 envelope credits on email verification, no credit card required) round out the platform, making zSign accessible from initial evaluation through high-volume production use.