import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
import { ResourceTemplate } from '@modelcontextprotocol/sdk/server/mcp.js';
import type { ReadResourceResult } from '@modelcontextprotocol/sdk/types.js';
import { ErrorCode, McpError } from './lib/errors.js';
import type { ResourceStore } from './lib/resource-store.js';
const RESULT_TEMPLATE = new ResourceTemplate('filesystem-mcp://result/{id}', {
list: undefined,
});
interface IconInfo {
src: string;
mimeType: string;
}
export function registerInstructionResource(
server: McpServer,
instructions: string,
iconInfo?: IconInfo
): void {
server.registerResource(
'filesystem-mcp-instructions',
'internal://instructions',
{
title: 'Server Instructions',
description:
'Guidance for using the filesystem-mcp MCP tools effectively.',
mimeType: 'text/markdown',
annotations: {
audience: ['assistant'],
priority: 0.8,
},
...(iconInfo
? {
icons: [
{
src: iconInfo.src,
mimeType: iconInfo.mimeType,
},
],
}
: {}),
},
(uri): ReadResourceResult => ({
contents: [
{
uri: uri.href,
mimeType: 'text/markdown',
text: instructions,
},
],
})
);
}
export function registerResultResources(
server: McpServer,
store: ResourceStore,
iconInfo?: IconInfo
): void {
server.registerResource(
'filesystem-mcp-result',
RESULT_TEMPLATE,
{
title: 'Cached Tool Result',
description:
'Ephemeral cached tool output exposed as an MCP resource. Not guaranteed to be listed via resources/list.',
mimeType: 'text/plain',
annotations: {
audience: ['assistant'],
priority: 0.3,
},
...(iconInfo
? {
icons: [
{
src: iconInfo.src,
mimeType: iconInfo.mimeType,
},
],
}
: {}),
},
(uri, variables): ReadResourceResult => {
const { id } = variables;
if (typeof id !== 'string' || id.length === 0) {
throw new McpError(ErrorCode.E_INVALID_INPUT, 'Missing resource id');
}
const entry = store.getText(uri.toString());
return {
contents: [
{
uri: entry.uri,
mimeType: entry.mimeType,
text: entry.text,
},
],
};
}
);
}
