import type { McpServer } from '@modelcontextprotocol/sdk/server/mcp.js';
export type AiAssistResult =
| { ok: true; text: string; model?: string }
| { ok: false; reason: 'sampling_not_supported' | 'non_text_response' | 'error'; message: string };
export function clientSupportsSampling(server: McpServer): boolean {
const caps = server.server.getClientCapabilities?.();
// ClientCapabilities.sampling is optional. If present, sampling is supported.
return Boolean((caps as any)?.sampling);
}
export async function sampleText(opts: {
server: McpServer;
systemPrompt: string;
userText: string;
maxTokens?: number;
temperature?: number;
}): Promise<AiAssistResult> {
const { server, systemPrompt, userText, maxTokens = 900, temperature = 0 } = opts;
if (!clientSupportsSampling(server)) {
return {
ok: false,
reason: 'sampling_not_supported',
message: '클라이언트가 LLM 샘플링(sampling/createMessage)을 지원하지 않습니다. (aiAssist=false로 사용하거나, sampling 지원 클라이언트를 사용하세요.)',
};
}
try {
const resp = await server.server.createMessage({
systemPrompt,
messages: [
{
role: 'user',
content: { type: 'text', text: userText },
},
],
temperature,
maxTokens,
includeContext: 'none',
});
if (resp.content.type !== 'text') {
return { ok: false, reason: 'non_text_response', message: 'LLM 응답이 텍스트가 아닙니다.' };
}
return { ok: true, text: resp.content.text, model: resp.model };
} catch (e: unknown) {
return {
ok: false,
reason: 'error',
message: `LLM 샘플링 실패: ${e instanceof Error ? e.message : String(e)}`,
};
}
}
export function tryParseJson<T>(text: string): { ok: true; value: T } | { ok: false } {
try {
const trimmed = text.trim();
const start = trimmed.indexOf('{');
const end = trimmed.lastIndexOf('}');
if (start >= 0 && end > start) {
const slice = trimmed.slice(start, end + 1);
return { ok: true, value: JSON.parse(slice) as T };
}
return { ok: false };
} catch {
return { ok: false };
}
}
