.. index:: single: mcp_resource_protocol
.. _mcp_resource_protocol/0:

.. rst-class:: right

**protocol**

``mcp_resource_protocol``
=========================

Protocol for Logtalk objects that provide resources to be exposed via an MCP (Model Context Protocol) server. Implements the MCP 2025-06-18 specification. Implementing objects must define the set of resources available and handle resource read requests. Resources expose data and content from the application that MCP clients can access.

| **Availability:** 
|    ``logtalk_load(mcp_server(loader))``

| **Author:** Paulo Moura
| **Version:** 0:2:0
| **Date:** 2026-02-24

| **Compilation flags:**
|    ``static``


| **Dependencies:**
|   (none)


| **Remarks:**

   - Capabilities: Objects providing resources must declare ``resources`` in their ``capabilities/1`` predicate (from the ``mcp_tool_protocol`` protocol). The server will then advertise the ``resources`` capability and handle ``resources/list`` and ``resources/read`` requests.
   - Resource descriptors: Each resource is described by a ``resource(URI, Name, Description, MimeType)`` or ``resource(URI, Name, Title, Description, MimeType)`` term where ``URI`` is the resource identifier (an atom), ``Name`` is a human-readable name (an atom), ``Title`` is an optional human-friendly display name (an atom), ``Description`` is a human-readable description (an atom), and ``MimeType`` is the MIME type of the resource content (an atom, e.g. ``'text/plain'``).
   - Resource contents: The ``resource_read/3`` predicate must return a result term. The result must be ``contents(ContentList)`` where each item is ``text_content(URI, MimeType, Text)`` for text resources or ``blob_content(URI, MimeType, Base64Data)`` for binary resources encoded as base64.

| **Inherited public predicates:**
|    (none)

.. contents::
   :local:
   :backlinks: top

Public predicates
-----------------

.. index:: resources/1
.. _mcp_resource_protocol/0::resources/1:

``resources/1``
^^^^^^^^^^^^^^^

Returns a list of resource descriptors available from this object. Each descriptor is a compound term ``resource(URI, Name, Description, MimeType)`` or ``resource(URI, Name, Title, Description, MimeType)`` where ``URI`` is the resource identifier (an atom, typically a URI like ``logtalk://my-app/data``), ``Name`` is a human-readable name (an atom), ``Title`` is an optional human-friendly display name (an atom), ``Description`` is a human-readable description (an atom), and ``MimeType`` is the MIME type (an atom, e.g. ``'text/plain'``, ``'application/json'``).

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``resources(Resources)``
| **Mode and number of proofs:**
|    ``resources(-list(compound))`` - ``one``


------------

.. index:: resource_read/3
.. _mcp_resource_protocol/0::resource_read/3:

``resource_read/3``
^^^^^^^^^^^^^^^^^^^

Handles a resource read request. ``URI`` is the resource identifier (as declared in ``resources/1``), ``Arguments`` is a list of ``ArgumentName-Value`` pairs (currently unused but reserved for future use), and ``Result`` is unified with the resource result. The result must be ``contents(ContentList)`` where each content item is either ``text_content(URI, MimeType, Text)`` for text resources or ``blob_content(URI, MimeType, Base64Data)`` for binary resources encoded as base64. ``Text`` and ``Base64Data`` must be atoms.

| **Compilation flags:**
|    ``static``

| **Template:**
|    ``resource_read(URI,Arguments,Result)``
| **Mode and number of proofs:**
|    ``resource_read(+atom,+list(pair),--compound)`` - ``one``


------------

Protected predicates
--------------------

(none)

Private predicates
------------------

(none)

Operators
---------

(none)