File size: 5,694 Bytes
4e23b01 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 | import { ErrorCodes, Error2 } from '#/errors';
import type { McpServerHttpConfig } from './config-schema';
import { Client } from '@modelcontextprotocol/sdk/client/index.js';
import type { OAuthClientProvider } from '@modelcontextprotocol/sdk/client/auth.js';
import { StreamableHTTPClientTransport } from '@modelcontextprotocol/sdk/client/streamableHttp.js';
import {
buildRequestOptions,
KIMI_MCP_CLIENT_NAME,
KIMI_MCP_CLIENT_VERSION,
MCP_LIVENESS_PROBE_TIMEOUT_MS,
toMcpToolDefinition,
toMcpToolResult,
type UnexpectedCloseListener,
type UnexpectedCloseReason,
} from './client-shared';
import { buildMcpRemoteHeaders } from './client-remote';
import { createMcpOAuthFetch } from './oauth/provider';
import type { MCPClient, MCPToolDefinition, MCPToolResult } from './types';
export interface HttpMcpClientOptions {
readonly clientName?: string;
readonly clientVersion?: string;
readonly startupTimeoutMs?: number;
readonly toolCallTimeoutMs?: number;
readonly envLookup?: (name: string) => string | undefined;
readonly fetch?: typeof fetch;
readonly oauthProvider?: OAuthClientProvider;
}
export class HttpMcpClient implements MCPClient {
private readonly client: Client;
private readonly transport: StreamableHTTPClientTransport;
private readonly startupTimeoutMs?: number;
private readonly toolCallTimeoutMs?: number;
private started = false;
private closed = false;
private ready = false;
private hooksInstalled = false;
private unexpectedCloseListener: UnexpectedCloseListener | undefined;
private lastTransportError: Error | undefined;
private pendingUnexpectedClose: UnexpectedCloseReason | undefined;
private unexpectedCloseFired = false;
constructor(config: McpServerHttpConfig, options: HttpMcpClientOptions = {}) {
const envLookup = options.envLookup ?? ((name) => process.env[name]);
const headers = buildMcpHttpHeaders(config, envLookup);
this.transport = new StreamableHTTPClientTransport(new URL(config.url), {
requestInit: headers !== undefined ? { headers } : undefined,
fetch: createMcpOAuthFetch(options.oauthProvider, options.fetch),
authProvider: options.oauthProvider,
});
this.client = new Client({
name: options.clientName ?? KIMI_MCP_CLIENT_NAME,
version: options.clientVersion ?? KIMI_MCP_CLIENT_VERSION,
});
this.startupTimeoutMs = options.startupTimeoutMs;
this.toolCallTimeoutMs = options.toolCallTimeoutMs;
}
async connect(): Promise<void> {
if (this.closed) {
throw new Error2(ErrorCodes.MCP_STARTUP_FAILED, 'MCP HTTP client is closed');
}
if (this.started) return;
this.started = true;
this.installTransportHooks();
try {
await this.client.connect(
this.transport,
buildRequestOptions(this.startupTimeoutMs, undefined),
);
} catch (error) {
await this.closeStartedClient();
throw error;
}
if (this.closed) {
await this.closeStartedClient();
throw new Error2(ErrorCodes.MCP_STARTUP_FAILED, 'MCP HTTP client was closed during startup');
}
this.ready = true;
}
async close(): Promise<void> {
if (this.closed) return;
this.closed = true;
await this.closeStartedClient();
}
onUnexpectedClose(listener: UnexpectedCloseListener): void {
this.unexpectedCloseListener = listener;
const pending = this.pendingUnexpectedClose;
if (pending !== undefined) {
this.pendingUnexpectedClose = undefined;
listener(pending);
}
}
async listTools(): Promise<MCPToolDefinition[]> {
const result = await this.client.listTools(
undefined,
buildRequestOptions(this.startupTimeoutMs, undefined),
);
return result.tools.map(toMcpToolDefinition);
}
async callTool(
name: string,
args: Record<string, unknown>,
signal?: AbortSignal,
): Promise<MCPToolResult> {
const requestOptions = buildRequestOptions(this.toolCallTimeoutMs, signal);
const result = await this.client.callTool({ name, arguments: args }, undefined, requestOptions);
return toMcpToolResult(result);
}
async ping(signal?: AbortSignal): Promise<void> {
await this.client.ping(buildRequestOptions(MCP_LIVENESS_PROBE_TIMEOUT_MS, signal));
}
private async closeStartedClient(): Promise<void> {
if (!this.started) return;
this.started = false;
await this.client.close();
}
private installTransportHooks(): void {
if (this.hooksInstalled) return;
this.hooksInstalled = true;
this.client.onclose = () => {
if (this.closed) return;
if (!this.ready) return;
this.fireUnexpectedClose({ error: this.lastTransportError });
};
this.client.onerror = (error) => {
this.lastTransportError = error;
if (this.closed) return;
if (!this.ready) return;
if (isTerminalTransportError(error)) {
this.fireUnexpectedClose({ error });
}
};
}
private fireUnexpectedClose(reason: UnexpectedCloseReason): void {
if (this.unexpectedCloseFired) return;
this.unexpectedCloseFired = true;
const listener = this.unexpectedCloseListener;
if (listener !== undefined) {
listener(reason);
} else {
this.pendingUnexpectedClose = reason;
}
}
}
export function isTerminalTransportError(error: Error): boolean {
if (error.name === 'UnauthorizedError') return true;
if (/Maximum reconnection attempts/i.test(error.message)) return true;
return false;
}
export function buildMcpHttpHeaders(
config: McpServerHttpConfig,
envLookup: (name: string) => string | undefined,
): Record<string, string> | undefined {
return buildMcpRemoteHeaders(config, envLookup);
}
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