Resources

What is a Resource?

Resources are a way to expose data content — documents, files, database query results, or any structured information — to AI clients via the MCP resources/read method. Unlike tools (which execute actions), resources provide read-only content that the AI can reference. Think of resources as:

Documentation or knowledge base articles the AI should be aware of
Real-time data from your database (e.g., product catalog, user list)
Static configuration or reference content
WordPress posts/pages exposed as MCP-readable content

Resource Properties

Property	Description
URI	Unique identifier for the resource (e.g., `docs://intro`)
Name	Human-readable display name
Description	What the resource contains; used by AI for discovery
MIME Type	Content type (e.g., `text/plain`, `application/json`, `text/markdown`)
Data Source Type	Where the content comes from
Data Source Config	Configuration object for the chosen data source
Template URI	URI template (RFC 6570) for parameterized resources

Resource URI

Every resource has a unique URI that serves as its identifier. Any URI scheme is valid:

docs://getting-started
config://app-settings
resource://products/featured
file:///data/report.json

AI clients reference resources by URI when calling resources/read.

Data Source Types

Type	Description
`static`	Content stored directly in `data_source_config.content`
`url`	Content fetched from an external URL at read time
`wp_query`	Content generated from a WordPress query (posts, pages, CPTs)
`callback`	Content generated by a custom registered PHP function

static

The simplest type. Define the content directly in the editor — it never changes unless you update it:

{
  "content": "# API Documentation\n\nThis server provides tools for managing customer records."
}

Use static resources for documentation, configuration, or any content that changes infrequently.

url

Content is fetched from an external URL each time the resource is read. The fetch happens server-side from WordPress, so it works behind firewalls:

{
  "url": "https://api.example.com/data.json",
  "cache_ttl": 300
}

cache_ttl (optional, seconds) caches the remote response to avoid hitting the upstream URL on every read. Default is 0 (no cache).

wp_query

Query your own WordPress database and expose the results as a resource. Accepts any standard WP_Query argument:

{
  "post_type": "post",
  "posts_per_page": 10,
  "orderby": "date",
  "order": "DESC",
  "post_status": "publish"
}

Common uses: blog post lists, WooCommerce products, custom post types, page content.

callback

Call a registered PHP function to generate content dynamically. The callback receives ($resource, $params) and must return a string:

{
  "callback": "my_plugin_inventory_callback"
}

function my_plugin_inventory_callback( $resource, $params ) {
    $items = get_option( 'my_plugin_inventory', [] );
    return json_encode( $items );
}

Resource Templates

Resource templates allow parameterized resources using URI templates (RFC 6570). Instead of a fixed URI pointing to one piece of content, a template defines a pattern where part of the URI is a variable the AI client fills in at read time.

How Templates Work

Set the Template URI field to a pattern with {variable} placeholders:

resource://products/{product_id}
docs://posts/{slug}
config://users/{user_id}/settings

When an AI client calls resources/templates/list, it receives the template pattern. The client then substitutes concrete values and calls resources/read with the expanded URI:

# Template:
resource://products/{product_id}

# Expanded URI requested by client:
resource://products/123
resource://products/456

Static URI vs Template URI

	Static URI	Template URI
MCP method	`resources/list`	`resources/templates/list`
URI	Fixed, e.g. `docs://intro`	Pattern, e.g. `docs://posts/{slug}`
Use case	Single document	Family of documents with variable parts
Data source	Any type	Typically `callback` or `url` with the variable forwarded

Template Example

A resource that serves any WordPress post by slug:

Field	Value
URI	`wp://posts/latest`
Name	`Post by Slug`
Template URI	`wp://posts/{slug}`
Data Source Type	`callback`
Data Source Config	`{ "callback": "getmcp_get_post_by_slug" }`

function getmcp_get_post_by_slug( $resource, $params ) {
    $slug = $params['slug'] ?? '';
    $post = get_page_by_path( $slug, OBJECT, 'post' );
    if ( ! $post ) return 'Post not found.';
    return $post->post_title . "\n\n" . wp_strip_all_tags( $post->post_content );
}

The AI client calls resources/read with wp://posts/my-post-slug and receives that post’s content.

Creating a Resource

Open the Resources Tab

Inside a server, click the Resources tab.

Click Add Resource

Click Add Resource to open the resource editor.

Set URI and Name

Enter a URI (e.g., docs://api-overview) and a human-readable name.

Choose Data Source Type

Select the data source type and fill in the corresponding config fields.

Set Template URI (optional)

If this is a parameterized resource, add a URI template pattern (e.g., docs://posts/{slug}).

Save

Click Save. The resource is now available via resources/list (or resources/templates/list if a template URI is set) and resources/read.

MCP Protocol

Resources integrate with the standard MCP protocol methods:

resources/list — Returns all resources that have a fixed URI
resources/read — Returns the content of a specific resource by URI
resources/templates/list — Returns resources that have a template_uri set

Getting Started

Concepts

Guides

Use Cases

What is a Resource?

Resource Properties

Resource URI

Data Source Types

static

url

wp_query

callback

Resource Templates

How Templates Work

Static URI vs Template URI

Template Example

Creating a Resource

MCP Protocol

​What is a Resource?

​Resource Properties

​Resource URI

​Data Source Types

​static

​url

​wp_query

​callback

​Resource Templates

​How Templates Work

​Static URI vs Template URI

​Template Example

​Creating a Resource

​MCP Protocol

What is a Resource?

Resource Properties

Resource URI

Data Source Types

static

url

wp_query

callback

Resource Templates

How Templates Work

Static URI vs Template URI

Template Example

Creating a Resource

MCP Protocol