# Why we built Evergist > We wanted a free way for AI agents and scripts to pass secret notes safely, with no browser to drive and no third party to trust. Here's what we built. Source: https://evergist.com/blog/why-we-built-evergist/ Published: 2026-09-30 Updated: 2026-09-30 **Short answer:** we built Evergist to give away a free tool that lets AI agents and automated flows handle secret notes safely and easily. An agent runs one command or one MCP tool call, its own machine encrypts the note, and our server only ever holds ciphertext. Nobody has to trust our server or any other outside service with the secret, and no agent has to drive a browser. ## The problem Agents and scripts hand off secrets all day. A setup agent has a database password that a person needs. A CI job has an API key for the next job. A teammate asks for the `.env` file, or for a private note that shouldn't be public. The quickest move is to paste the secret into a chat, a ticket, or a pull request. Those places keep everything. The copy stays in history, search, backups, and exports long after anyone needs it. ## Why the existing sites didn't fit Secret-note sites already exist. They're built for a person in a browser, who opens a page, types the note, clicks a button, and copies a link. An agent can only do that by driving a browser. That's slow, and it's fragile, because the agent has to find the right box and the right button on a page made for human eyes. There's a second problem. On some of those services the server does the encrypting, so the operator can read what you send. We checked seven of them in [our comparison](https://evergist.com/blog/private-note-sharing-compared/). None of those seven had an MCP server. Tools outside that set do, Vaulted among them, and [our MCP post](https://evergist.com/blog/mcp-server-for-sharing-secrets/) describes it. ## What we wanted - **One step.** A single command, or a single MCP tool call. No browser. - **Encryption on the agent's own machine.** The note is locked before anything goes over the network. - **A server that only holds ciphertext.** We never receive the key, so "we can't read it" is a fact you can check and doesn't depend on our word. - **Free, with no accounts.** Nothing to sign up for, no cookies, and request logging is off. - **The same thing for people.** The [website](https://evergist.com/#new-note) makes the same kind of link in your browser. ## How it works in one paragraph Your machine makes a random key and uses it to encrypt the note. It uploads the encrypted note, and the server sends back an ID. The link you share is that ID plus the key, and the key sits after the `#` sign, a part of a link that browsers never send to a server. Whoever has the full link can open the note. The server deletes it at the expiry time you chose, or right after its last allowed view. The cipher is AES-256-GCM, and we publish [the full encryption scheme](https://evergist.com/security/#the-encryption-scheme). ## What it looks like ```sh npx -y evergist create .env --views 1 --expires 1h npx -y evergist read "https://evergist.com/g/#" npx -y evergist mcp ``` The first line shares a file as a link that opens once and expires in an hour. The second reads a note. The third starts the local MCP server, which gives MCP clients like Claude, Cursor, and Codex tools to create, read, check, and delete notes. All three need Node.js 20 or newer. The [agent guide](https://evergist.com/agents/) covers setup for each client. ## What it doesn't do We'd rather tell you the limits than have you find them. - **Anyone with the link can read the note.** The link is the key. If it lands in a chat that keeps history, the note is readable until it expires or runs out of views. Use one view and a short expiry, or add a password and send it separately. - **In the browser, you trust the page we serve.** The encryption code comes from our server, like every browser-based encryption tool. If someone compromised our server, they could serve altered code. The command line tool is a single file you can download, read, and pin. - **Size isn't hidden.** The encrypted note is about as long as the original, so its length shows. - **Our host sees connections.** Evergist runs on Cloudflare, which can see that some IP address connected at some time. It never sees the key, the password, or the text. - **Lose the link and the note is gone.** We can't recover it. - **Text only.** Notes hold up to 512 KiB of text and last 30 days at most. There are no file uploads. ## Further reading - [How Evergist is built](https://evergist.com/blog/introducing-evergist/): the architecture and design decisions in depth - [How Evergist's encryption works](https://evergist.com/security/): every step, and four ways to verify it - [Agent guide](https://evergist.com/agents/): MCP server, CLI, SKILL.md, and REST API ## Next steps - Agent instructions, with every command: https://evergist.com/SKILL.md - MCP server, CLI, and REST API setup: https://evergist.com/agents.md