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readResource

Reads a resource from the MCP server.

Will throw an error if:

  • The server did not declare 'resources' in the capabilities section.
  • The server did not list this resource URI in the resources list.
  • The resource read fails.

Syntax​

app.readResource(uri: string): Promise<MCPReadResourceResult>

Parameters​

  • uri: The URI of the resource to read

Returns​

A Promise that resolves to an object containing:

  • contents: An array of resource contents (text or blob)

Each content item has:

  • uri: The URI of the resource
  • mimeType: Optional MIME type of the content
  • text: The text content (for text resources)
  • blob: The base64-encoded blob content (for binary resources)

Example​

import { mcpShell } from 'expect-mcp';
import { test, expect } from 'vitest';

test('read a resource from the server', async () => {
  const app = mcpShell('node resource-server.js');
  await app.initialize();

  // Read a text resource
  const result = await app.readResource('file:///example.txt');

  expect(result.contents).toBeDefined();
  expect(result.contents[0].text).toBeDefined();
  expect(result.contents[0].mimeType).toBe('text/plain');

  app.close();
});

Error Handling​

If the resource read fails, an error will be thrown:

try {
  await app.readResource('file:///nonexistent.txt');
} catch (error) {
  expect(error.name).toBe('ResourceCallError');
}

Timeout Configuration​

You can configure the timeout for resource reads using the requestTimeout option:

const app = mcpShell('node slow-resource-server.js', {
  requestTimeout: 30000, // 30 seconds
});

const result = await app.readResource('file:///large-file.txt');

See Also​