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 { globalMetrics } from './lib/observability.js';
import type { ResourceStore } from './lib/resource-store.js';
import { buildToolCatalog } from './resources/tool-catalog.js';
import { buildWorkflowGuide } from './resources/workflows.js';
import { type IconInfo, withDefaultIcons } from './tools/shared.js';
const RESULT_TEMPLATE = new ResourceTemplate('filesystem-mcp://result/{id}', {
list: undefined,
});
const INSTRUCTIONS_RESOURCE_NAME = 'filesystem-mcp-instructions';
const INSTRUCTIONS_RESOURCE_URI = 'internal://instructions';
const INSTRUCTIONS_RESOURCE_DESCRIPTION =
'Guidance for using the filesystem-mcp MCP tools effectively.';
const RESULT_RESOURCE_NAME = 'filesystem-mcp-result';
const RESULT_RESOURCE_DESCRIPTION =
'Ephemeral cached tool output exposed as an MCP resource. Not guaranteed to be listed via resources/list.';
const METRICS_RESOURCE_NAME = 'filesystem-mcp-metrics';
const METRICS_RESOURCE_URI = 'filesystem-mcp://metrics';
const METRICS_RESOURCE_DESCRIPTION =
'Live per-tool call/error/avgDurationMs metrics snapshot.';
const CATALOG_RESOURCE_NAME = 'filesystem-mcp-catalog';
const CATALOG_RESOURCE_URI = 'internal://tool-catalog';
const CATALOG_RESOURCE_DESCRIPTION =
'Detailed catalog of tools and their inter-dependencies.';
const WORKFLOW_RESOURCE_NAME = 'filesystem-mcp-workflows';
const WORKFLOW_RESOURCE_URI = 'internal://workflows';
const WORKFLOW_RESOURCE_DESCRIPTION = 'Recommended workflows for common tasks.';
export function registerInstructionResource(
server: McpServer,
instructions: string,
iconInfo?: IconInfo
): void {
server.registerResource(
INSTRUCTIONS_RESOURCE_NAME,
INSTRUCTIONS_RESOURCE_URI,
withDefaultIcons(
{
title: 'Server Instructions',
description: INSTRUCTIONS_RESOURCE_DESCRIPTION,
mimeType: 'text/markdown',
annotations: {
audience: ['assistant'],
priority: 0.8,
},
},
iconInfo
),
(uri): ReadResourceResult => ({
contents: [
{
uri: uri.href,
mimeType: 'text/markdown',
text: instructions,
},
],
})
);
}
export function registerToolCatalogResource(
server: McpServer,
iconInfo?: IconInfo
): void {
server.registerResource(
CATALOG_RESOURCE_NAME,
CATALOG_RESOURCE_URI,
withDefaultIcons(
{
title: 'Tool Catalog',
description: CATALOG_RESOURCE_DESCRIPTION,
mimeType: 'text/markdown',
annotations: {
audience: ['assistant'],
priority: 0.7,
},
},
iconInfo
),
(uri): ReadResourceResult => ({
contents: [
{
uri: uri.href,
mimeType: 'text/markdown',
text: buildToolCatalog(),
},
],
})
);
}
export function registerWorkflowGuideResource(
server: McpServer,
iconInfo?: IconInfo
): void {
server.registerResource(
WORKFLOW_RESOURCE_NAME,
WORKFLOW_RESOURCE_URI,
withDefaultIcons(
{
title: 'Workflow Guide',
description: WORKFLOW_RESOURCE_DESCRIPTION,
mimeType: 'text/markdown',
annotations: {
audience: ['assistant'],
priority: 0.6,
},
},
iconInfo
),
(uri): ReadResourceResult => ({
contents: [
{
uri: uri.href,
mimeType: 'text/markdown',
text: buildWorkflowGuide(),
},
],
})
);
}
export function registerResultResources(
server: McpServer,
store: ResourceStore,
iconInfo?: IconInfo
): void {
server.registerResource(
RESULT_RESOURCE_NAME,
RESULT_TEMPLATE,
withDefaultIcons(
{
title: 'Cached Tool Result',
description: RESULT_RESOURCE_DESCRIPTION,
mimeType: 'text/plain',
annotations: {
audience: ['assistant'],
priority: 0.3,
},
},
iconInfo
),
(uri, variables): ReadResourceResult => {
const { id } = variables;
if (typeof id !== 'string' || id.length === 0) {
throw new McpError(
ErrorCode.E_NOT_FOUND,
'Cached result has expired — re-run the tool to regenerate.'
);
}
const entry = store.getText(uri.toString());
return {
contents: [
{
uri: entry.uri,
mimeType: entry.mimeType,
text: entry.text,
},
],
};
}
);
}
export function registerMetricsResource(
server: McpServer,
iconInfo?: IconInfo
): void {
server.registerResource(
METRICS_RESOURCE_NAME,
METRICS_RESOURCE_URI,
withDefaultIcons(
{
title: 'Tool Metrics',
description: METRICS_RESOURCE_DESCRIPTION,
mimeType: 'application/json',
annotations: {
audience: ['assistant'],
priority: 0.5,
},
},
iconInfo
),
(uri): ReadResourceResult => {
const snapshot: Record<
string,
{ calls: number; errors: number; avgDurationMs: number }
> = {};
for (const [tool, m] of globalMetrics) {
snapshot[tool] = {
calls: m.calls,
errors: m.errors,
avgDurationMs:
m.calls > 0
? parseFloat((m.totalDurationMs / m.calls).toFixed(2))
: 0,
};
}
return {
contents: [
{
uri: uri.href,
mimeType: 'application/json',
text: JSON.stringify({ ok: true, metrics: snapshot }, null, 2),
},
],
};
}
);
}
