Accessing resources

Overview

• MCP client needs ability to request resources defined in the MCP server
• A single read_resource() function handles all resource requests from the client

Function Implementation

Imports Required

• json module for parsing JSON data
• AnyUrl from PyDantic for type handling

Function Logic

• Takes a URI argument specifying which resource to fetch
• Calls await self. session. read_resource() with the URI wrapped in AnyUrl
• Extracts the first item from result. contents list

Response Parsing by MIME Type

• Check the mime_type property from the resource response
• If MIME type is application/json: parse text content using json. loads() and return parsed data
• Otherwise: return raw text content as-is

Resource Type Handling

• Uses isinstance() check for ResourceTextContents to validate resource type
• Different MIME types trigger different parsing strategies

Integration

• The read_resource() function is called by other parts of the application
• Enables features like document mention/insertion in CLI prompts
• Allows Claude to receive document contents directly in prompts without needing to call tools

Takeaways

• MCP client uses a single read_resource() function to fetch any resource from the server by URI
• Response parsing depends on MIME type: application/json requires json. loads() parsing, other types return raw text
• The function extracts content from result. contents list and validates it's a ResourceTextContents type
• Resource reading enables Claude to receive document contents directly in prompts without tool calls