DEVLog - May

Discover what happened in May 2026. AI agents can now send envelopes through the SignatureAPI MCP server, and I published a free Czech course for Spanish speakers.

Jun 1, 2026 · 2 min read

Devlog

May had 348 commits across 6 repositories. Fewer projects, but one of them was a big step for SignatureAPI. AI agents can now send documents for signature.

I wrote this devlog later, from my GitHub history, to fill a gap in the series.

AI agents meet SignatureAPI

SignatureAPI now has an MCP server. MCP stands for Model Context Protocol. It is a standard way for AI assistants like ChatGPT or Claude to use outside tools. Think of it as a plug that any assistant can connect to. With our MCP server, you can ask an assistant to send an envelope (a set of documents to sign), and it does it through SignatureAPI.

Most of my 131 commits on SignatureAPI went here. Some of the pieces:

Server instructions that explain our concepts to the AI, so it knows what an envelope or a recipient is.
Tools to cancel and delete envelopes.
A list of connected applications, so you can see which assistants have access and disconnect them.
A new way to upload files, built on CloudFront and Lambda@Edge.
A per-account flag, so we could open the MCP server as a private beta.

ChatGPT had trouble with the login flow at first. I fixed it by proxying our OAuth authorization server, the part that handles who is allowed to connect.

On the website, I wrote the MCP docs, including a quickstart for people who do not write code. I also added a page that shows signing ceremonies driven by agents. SignatureAPI also learned Dutch this month, both in the app and on the website.

SignatureAPI Electronic signature API for workflows, applications and platforms.

signatureapi.com

Learning Czech in Spanish

I created a new public repository: Aprendiendo Checo. It is an interactive Czech course for Spanish speakers, in the style of the Assimil method.

It is plain HTML hosted on GitHub Pages. Each lesson has a button that reads the Czech text aloud with the browser’s text-to-speech. Words are colored by grammatical gender, and there are exercises. By the end of the month it had seven lessons. They cover topics like a café, numbers, family and likes, and end with a review lesson.

A lesson in Aprendiendo Checo. Each line has a play button, and words are colored by gender.

The repository also includes the prompt and the template I use to generate new lessons, so anyone can see how it is made. It is open source under the MIT license.

Aprendiendo Checo Curso interactivo de checo para hispanohablantes, con pronunciación TTS, géneros por color y ejercicios.

github.com

Guides for schools

ParentSignature got 95 commits, mostly new guides for schools. I wrote about AI acceptable use policies, field trip risk assessments and permission forms. I also wrote about why parents put off signing permission slips. I fixed a few email delivery details too.