57 lines
1.6 KiB
JavaScript
57 lines
1.6 KiB
JavaScript
const ACCEPT = "application/json, text/event-stream";
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function parseMcpResponse(text) {
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const trimmed = text.trim();
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if (!trimmed) throw new Error("Empty MCP response");
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if (trimmed.startsWith("{")) {
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return JSON.parse(trimmed);
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}
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if (trimmed.includes("event:") || trimmed.includes("data:")) {
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let payload = "";
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for (const line of trimmed.split(/\r?\n/)) {
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if (line.startsWith("data:")) payload += line.slice(5).trim();
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}
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if (payload.startsWith("{")) return JSON.parse(payload);
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}
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throw new Error(`Unrecognized MCP response format: ${trimmed.slice(0, 200)}`);
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}
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export class McpClient {
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constructor(url) {
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this.url = url;
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this.seq = 0;
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}
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async request(method, params = {}) {
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this.seq += 1;
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const res = await fetch(this.url, {
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method: "POST",
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headers: { "Content-Type": "application/json", Accept: ACCEPT },
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body: JSON.stringify({ jsonrpc: "2.0", id: this.seq, method, params }),
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});
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if (!res.ok) {
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throw new Error(`MCP HTTP ${res.status}: ${(await res.text()).slice(0, 300)}`);
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}
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const rpc = parseMcpResponse(await res.text());
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if (rpc.error) throw new Error(`MCP RPC error ${rpc.error.code}: ${rpc.error.message}`);
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return rpc;
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}
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async listTools() {
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const rpc = await this.request("tools/list");
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return rpc.result?.tools ?? [];
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}
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async callTool(name, args = {}) {
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const rpc = await this.request("tools/call", { name, arguments: args });
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return rpc.result;
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}
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}
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export function textContentFrom(result) {
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if (!result?.content) return "";
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return result.content
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.map((b) => (b.type === "text" ? b.text : JSON.stringify(b)))
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.join(" ");
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}
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