Emissario
PT Ask the AI
For technical teams · Free · MIT

Install Emissario.

Emissario is free and open source under the MIT license. It is a single binary: no runtime, no database server. The only thing the host needs is git.

This page is technical. It shows how to install Emissario yourself, with commands in a server's terminal. Rather have it all set up for you, with no technician needed? See the set-up service.

  1. Install the binary

    Pick your platform and paste the command.

    macOS (Apple Silicon)
    curl -sL https://github.com/MateusMoutinhoOrg/Emissario/releases/latest/download/macarm64.bin -o emissario && chmod +x emissario && sudo mv emissario /usr/local/bin/ && emissario version
    macOS (Intel)
    curl -sL https://github.com/MateusMoutinhoOrg/Emissario/releases/latest/download/mac86.bin -o emissario && chmod +x emissario && sudo mv emissario /usr/local/bin/ && emissario version
    Linux (amd64)
    curl -sL https://github.com/MateusMoutinhoOrg/Emissario/releases/latest/download/linux86.out -o emissario && chmod +x emissario && sudo mv emissario /usr/local/bin/ && emissario version
    Linux (arm64)
    curl -sL https://github.com/MateusMoutinhoOrg/Emissario/releases/latest/download/linuxarm64.out -o emissario && chmod +x emissario && sudo mv emissario /usr/local/bin/ && emissario version
    Linux (32-bit)
    curl -sL https://github.com/MateusMoutinhoOrg/Emissario/releases/latest/download/linuxi32.out -o emissario && chmod +x emissario && sudo mv emissario /usr/local/bin/ && emissario version
    Windows (64-bit) — PowerShell
    $dir="$HOME\.local\bin"; New-Item -ItemType Directory -Force -Path $dir | Out-Null; curl.exe -sL https://github.com/MateusMoutinhoOrg/Emissario/releases/latest/download/windows86.exe -o "$dir\emissario.exe"; [Environment]::SetEnvironmentVariable('PATH', [Environment]::GetEnvironmentVariable('PATH','User') + ";$dir", 'User')
    Windows (32-bit) — PowerShell
    $dir="$HOME\.local\bin"; New-Item -ItemType Directory -Force -Path $dir | Out-Null; curl.exe -sL https://github.com/MateusMoutinhoOrg/Emissario/releases/latest/download/windowsi32.exe -o "$dir\emissario.exe"; [Environment]::SetEnvironmentVariable('PATH', [Environment]::GetEnvironmentVariable('PATH','User') + ";$dir", 'User')
    From a checkout — needs Go 1.25+
    go build -o emissario ./cmd/main && sudo mv emissario /usr/local/bin/ && emissario version

    Source: CliInstall. emissario help lists every command.

  2. Start it

    The quick start of the README:

    $ export EMISSARIO_ENCRYPT_KEY=$(emissario generate-encrypt-key)   # store it safely: losing it loses every database and backup
$ emissario add-backoffice-user --username admin --email admin@example.com --role root   # prints the password once
$ emissario start-server --insecure-http --addr 127.0.0.1:3000                            # plain http, local only

    Open http://127.0.0.1:3000/admin/login and sign in.

    In production, drop --insecure-http, serve over https, and set EMISSARIO_BACKOFFICE_SECRET so that sessions survive a restart. Every command that opens a database needs EMISSARIO_ENCRYPT_KEY; --notencrypt keeps the data in clear, for local debugging only.

  3. Set it up from the backoffice

    Signed in as a root:

    • Website source: the repository, the branch and the sync time of your site.
    • Privacy: a preset — lgpd@1, gdpr@1 or lgpd-gdpr@1 — or each value.
    • Agent: the instructions repository, the model and the token limits — then turn it on.
    • Two-factor: protect your own account with an authenticator app.

  4. Build your website

    Emissario serves the frontend/ folder of your repository, as committed. Let a coding agent know the routes your pages can call and the files your agent reads:

    $ emissario drop-front-skills  --path ../my-site    # in the website repository
$ emissario drop-agents-skills --path ../my-agent   # in the agent instructions repository
Documentation

Every feature is documented.

The full index lives in the README of the repository. Open the index

Commands

Every command of the CLI.

Read

WebsiteSource

Serve the site from a git repository.

Read

Agent

The public AI chat, its limits and its summaries.

Read

Backoffice

Users, roles, sessions and API tokens.

Read

Privacy

Encryption, IPs, retentions, LGPD and GDPR.

Read

ContactRequests

The contact form of the website.

Read

Visualization

Page views, recorded on the server.

Read

Backups

Take, download and restore snapshots.

Read

Rather have it done for you? Mateus Moutinho, the creator of Emissario, can set it up on your server. See the price →