Contracts — 1 of 20 skills in the Architect & BTP pack
In a chat, Word or Excel files aren't always generated: you get the document as structured text instead.
Lettre-Mission
The lightweight contract for short, one-off engagements.
Free, no account, no email — the command is all you need.
Already have it?
Nothing to install if it's already active
If this skill is already added in your Claude, there's no need to install it again. Just ask for what you want to do.
Not sure? Ask Claude: "which skills do you have available?"
“Use the engagement-letter skill to draft the lightweight contract for this short mission: …”
1 · The simplest way
Copy and paste into any AI chat
This button copies the whole skill. Paste it into Claude, ChatGPT, or Gemini, then describe what you need. No installation required.
In a chat, Word or Excel files can't always be generated: you'll receive the document as structured text instead, and Claude will flag it.
- This skill produces mandatory legal notices: review them before any professional use.
2 · Command line
/lettre-mission installs in 3 steps
For Claude Code. The skill installs on your computer and stays available across all your projects.
Prerequisites: Claude Code + Node.js
The skill runs inside Claude Code, Anthropic's AI assistant installed on your computer. Node.js is the engine that runs the install command. Both are free.
Open PowerShell
Click Start, type "PowerShell", then press Enter.
Paste the command
Right-click inside the PowerShell window (or press Ctrl + V) to paste the command below, then press Enter. Wait a few seconds.
npx educasium --skill lettre-mission --globalWhat you should see:
npx educasium --skill lettre-mission --global
Fetching https://raw.githubusercontent.com/Chappygo-OS/claude-meta-skills/main/dist/lettre-mission.zip
…
Installed "lettre-mission". Restart Claude Code to pick it up.
Restart Claude Code
In Claude Code, type /restart (or quit and relaunch Claude Code). The skill now appears in the command list.
Don't use a terminal?
Using Claude.ai in your browser?
The assisted install works through a .zip file imported into Claude.ai. It takes longer and asks for your email.
What the skill does
View the source codeIn detail.
For a feasibility study, a consultation, or a mission limited to one phase — a letter format, legally binding but concise (3-5 pages), without going through a full contract.
When to use it
For a short or one-off engagement that doesn't warrant a full contract.
Example usage
/lettre-mission Feasibility study for a rooftop addition, 4 weeks, lump sum €3,000...Download for free