MCP server

ERP DLM exposes an MCP (Model Context Protocol) server at /api/mcp that allows AI assistants to query ERP data in read-only mode.

What is MCP?

MCP is an open protocol for connecting language models with external data sources and tools. Through the MCP server, an assistant can:

List sales and purchase invoices.
Query customers, suppliers and products.
View the chart of accounts, journal entries and balances.
Get a treasury snapshot and bank movements.

Available transports

HTTP SSE (production / cloud)

Mounted inside the FastAPI application:

GET /api/mcp/sse — Server-Sent Events connection.
POST /api/mcp/messages/ — JSON-RPC message endpoint.

The mount is wired directly in backend/app/main.py through _McpBypassApp, preventing FastAPI middleware from breaking streaming responses.

stdio (local)

For local usage with Hermes or other stdio MCP clients:

cd backend
. .venv/bin/activate
python mcp_server.py

To require authentication in stdio as well, export MCP_AUTH_TOKEN.

Authentication

The HTTP transport requires the header Authorization: Bearer <token>. The token is SHA-256 hashed and looked up in api_tokens; it must be active, not expired, and have at least one api_access rule with:

resource_name = 'mcp' (global access), or
resource_name = '*' (wildcard), or
the concrete scope of the tool (e.g. mcp:invoices).

For the stdio transport, if MCP_AUTH_TOKEN is not exported, the server allows unlimited local access (useful for mono-tenant development).

Multi-tenant

The company_id field of api_tokens determines which company data the assistant sees. If it is NULL, all companies are queried (default behaviour in single-company installations). For SaaS multi-tenant it is recommended to set company_id on every token.

Exposed tools

The server exposes 13 read-only tools:

Tool	Scope	Description	Main parameters
`list_invoices`	`mcp:invoices`	Sales invoices	`status`, `date_from`, `date_to`, `client_id`, `paid`, `limit`, `offset`
`get_invoice`	`mcp:invoices`	Sales invoice detail	`invoice_id` or `document_number`
`list_purchase_invoices`	`mcp:purchase_invoices`	Purchase invoices	`status`, `date_from`, `date_to`, `supplier_id`, `paid`, `limit`, `offset`
`get_purchase_invoice`	`mcp:purchase_invoices`	Purchase invoice detail	`invoice_id` or `document_number`
`list_contacts`	`mcp:contacts`	Customers and/or suppliers	`contact_type`, `search`, `is_active`, `limit`, `offset`
`get_contact`	`mcp:contacts`	Contact detail	`contact_id`
`list_products`	`mcp:products`	Products	`search`, `family_code`, `is_active`, `limit`, `offset`
`get_product`	`mcp:products`	Product detail	`product_id` or `reference`
`list_accounts`	`mcp:accounting`	Chart of accounts	`fiscal_year_code`, `is_active`, `limit`, `offset`
`get_account_balance`	`mcp:accounting`	Account balance	`account_code`, `fiscal_year_code`
`list_journal_entries`	`mcp:accounting`	Journal entries	`fiscal_year_code`, `date_from`, `date_to`, `limit`, `offset`
`get_cash_flow`	`mcp:treasury`	Treasury snapshot	—
`list_bank_movements`	`mcp:banking`	Bank movements	`status`, `date_from`, `date_to`, `limit`, `offset`

Claude Desktop configuration example

{
  "mcpServers": {
    "erp-dlm": {
      "command": "npx",
      "args": ["-y", "@anthropic-ai/mcp-sse-proxy"],
      "env": {
        "SSE_URL": "https://erp.ovlicuo.com/api/mcp/sse",
        "MCP_AUTHORIZATION": "Bearer tok-..."
      }
    }
  }
}

More information

Official MCP documentation
ERP DLM REST API
Implementation file: backend/app/modules/mcp_server/server.py
SQL queries: backend/app/modules/mcp_server/queries.py
MCP authentication: backend/app/modules/mcp_server/auth.py