MCP Server and Claude Code Skill

The Frihet MCP server connects your AI assistant directly to your ERP. Create invoices by talking. Query expenses in natural language. Manage your entire business from your IDE.

You:     "Create an invoice for TechStart SL, 40 hours of consulting at 75 EUR/hour, due March 1st"
Claude:  Done. Invoice INV-2026-089 created. Total: 3,000.00 EUR + 21% VAT = 3,630.00 EUR.

31 tools. 6 resources. Zero boilerplate.

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Install

Requirements

• Claude Code, Claude Desktop, Cursor, Windsurf, Cline, or any MCP-compatible tool
• A Frihet account with API access (paid plans)

Local install (stdio transport)

Add this to your MCP config file:

{
  "mcpServers": {
    "frihet": {
      "command": "npx",
      "args": ["-y", "@frihet/mcp-server"],
      "env": {
        "FRIHET_API_KEY": "fri_your_key_here"
      }
    }
  }
}

Tool	Config file
Claude Code	~/.claude/mcp.json
Claude Desktop	~/Library/Application Support/Claude/claude_desktop_config.json
Cursor	.cursor/mcp.json or ~/.cursor/mcp.json
Windsurf	~/.windsurf/mcp.json
Cline	VS Code settings or .cline/mcp.json

The JSON config is identical for all tools. Only the file path changes.

Remote (no install)

Use the hosted endpoint at mcp.frihet.io — no local dependencies:

{
  "mcpServers": {
    "frihet": {
      "type": "streamable-http",
      "url": "https://mcp.frihet.io/mcp",
      "headers": {
        "Authorization": "Bearer fri_your_key_here"
      }
    }
  }
}

Same 31 tools, zero local setup. Runs on Cloudflare Workers.

Get your API key

1. Log into app.frihet.io
2. Go to Settings > API
3. Click Create API key
4. Copy the key (starts with fri_) — it's shown only once

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What you can do

These are real prompts, not marketing copy.

Invoicing

"Show me all unpaid invoices"
"Create an invoice for Acme SL with 10h of consulting at 95/hour"
"Mark invoice abc123 as paid"
"How much has Acme SL been invoiced this year?"

Expenses

"Log a 59.99 EUR expense for Adobe Creative Cloud, category: software, tax-deductible"
"List all expenses from January"
"What did I spend on travel last quarter?"

Clients

"Add a new client: TechStart SL, NIF B12345678, email admin@techstart.com"
"Show me all my clients"
"Update Acme SL's address to 1 Main Street, New York 10001"

Quotes

"Create a quote for Design Studio: logo design (2000 EUR) + brand guidelines (3500 EUR)"
"Show me all pending quotes"

Webhooks

"Set up a webhook to notify https://my-app.com/hook when invoices are paid"
"List all my active webhooks"

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Tools reference

Invoices

Tool	What it does
list_invoices	List invoices with pagination
get_invoice	Get full invoice details by ID
create_invoice	Create a new invoice with line items
update_invoice	Update any invoice field
delete_invoice	Permanently delete an invoice
search_invoices	Find invoices by client name

Expenses

Tool	What it does
list_expenses	List expenses with pagination
get_expense	Get expense details
create_expense	Record a new expense
update_expense	Modify an expense
delete_expense	Delete an expense

Clients

Tool	What it does
list_clients	List all clients
get_client	Get client details
create_client	Register a new client
update_client	Update client info
delete_client	Remove a client

Products

Tool	What it does
list_products	List products and services
get_product	Get product details
create_product	Add a product or service
update_product	Update pricing or details
delete_product	Remove a product

Quotes

Tool	What it does
list_quotes	List all quotes
get_quote	Get quote details
create_quote	Draft a new quote
update_quote	Modify a quote
delete_quote	Delete a quote

Webhooks

Tool	What it does
list_webhooks	List configured webhooks
get_webhook	Get webhook details
create_webhook	Register a new webhook endpoint
update_webhook	Modify events or URL
delete_webhook	Remove a webhook

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Claude Code Skill

Beyond raw MCP tools, Frihet ships a Claude Code skill that adds business intelligence: workflow recipes, formatted financial reports, and natural language commands.

Install the skill

# Clone and symlink
git clone https://github.com/berthelius/frihet-mcp.git
ln -s "$(pwd)/frihet-mcp/skill" ~/.claude/skills/frihet

Or download just the skill file:

curl -sL https://raw.githubusercontent.com/berthelius/frihet-mcp/main/skill/SKILL.md \
  -o ~/.claude/skills/frihet/SKILL.md --create-dirs

Skill commands

Command	What it does
/frihet status	Account overview: recent invoices, pending payments, month expenses
/frihet invoice	Create, list, or search invoices
/frihet expense	Log and query expenses
/frihet clients	Manage your client database
/frihet quote	Create and manage quotes
/frihet report	Financial summaries (P&L, quarterly, overdue)
/frihet webhooks	Configure automation triggers
/frihet setup	Guided setup and connection test

Example: Create an invoice

/frihet invoice "Acme SL, 40 hours of consulting at 75 EUR/hour, due March 1st"

The skill creates the invoice with line items, calculates VAT at 21%, and confirms the assigned number.

Example: Log expenses fast

/frihet expense "47.50 gasoline Feb 15"
/frihet expense "Adobe CC 59.99 software"
/frihet expense "Client lunch 23.40 restaurant"

The skill infers the category and marks deductibility automatically.

Example: Quarterly tax prep

/frihet report quarterly

Calculates automatically:

• Output VAT (collected on invoices)
• Input VAT (paid on deductible expenses)
• Net amount due or credit
• Data ready for your quarterly tax return

Example: Overdue follow-up

/frihet report unpaid

Lists overdue invoices sorted by amount, days past due, and suggests follow-up actions.

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Skill vs. MCP Server

	MCP Server	Skill
Scope	31 CRUD tools	Tools + business intelligence
Context	None	Tax rules, deductibility, calendar
Workflows	Single operations	Multi-step recipes (close, tax prep, conversion)
Output format	Raw JSON	Tables and readable summaries
Prerequisite	API key	API key + MCP server

The skill uses the MCP server underneath. It doesn't duplicate logic — it adds context.

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How it works

Your AI assistant          frihet-mcp           Frihet API
      |                        |                    |
      |-- "create invoice" --> |                    |
      |                        |-- POST /invoices ->|
      |                        |<-- 201 Created ----|
      |<-- "Invoice created" --|                    |

The MCP server translates natural language tool calls into REST API requests. It handles authentication, rate limiting (automatic retry on 429), pagination, and error mapping.

Environment variables

Variable	Required	Default
FRIHET_API_KEY	Yes	—
FRIHET_API_URL	No	https://api.frihet.io/v1

FRIHET_API_URL is useful if you point to a staging environment.

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API limits

Limit	Value
Requests per minute	100 per API key
Results per page	100 max (50 default)
Request body	1 MB max
Webhook payload	100 KB max
Webhooks per account	20 max

Rate limiting is handled automatically with exponential backoff.

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Why Frihet MCP

	Frihet	Holded	Billin	Quipu	Anfix
Official MCP server	Yes	No	No	No	No
Claude / Cursor / Windsurf	Yes	No	No	No	No
Public REST API	Yes	Yes	Limited	Yes	No
Webhooks with HMAC verification	Yes	No	No	No	No
AI assistant built-in	Yes	No	No	No	No
Open source tooling	Yes	No	No	No	No

No other Spanish ERP has an official MCP server.

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Security

• The API key is managed exclusively via environment variables in the MCP config
• The skill never displays, logs, or stores your API key
• All data travels encrypted between your AI assistant, the MCP server, and the Frihet API
• The MCP server is stateless — it stores nothing

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Links

• Source code (GitHub)
• npm package
• REST API reference
• Webhooks
• Remote endpoint
• MCP specification