`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)