Polymarket MCP Server

import { OAuthClientProvider, UnauthorizedError, } from "@modelcontextprotocol/sdk/client/auth.js"; import { OAuthClientInformation, OAuthClientInformationFull, OAuthClientMetadata, OAuthTokens, } from "@modelcontextprotocol/sdk/shared/auth.js"; import fs from "fs/promises"; import path from "path"; /** * Simple file-based OAuth provider for server-side authentication * Stores tokens in a JSON file so they persist across restarts */ export class SimpleOAuthProvider implements OAuthClientProvider { private _clientInformation?: OAuthClientInformationFull; private _tokens?: OAuthTokens; private _codeVerifier?: string; private _pendingAuthUrl?: string; private readonly _tokensFile: string; constructor( private readonly _redirectUrl: string, private readonly _clientMetadata: OAuthClientMetadata ) { this._tokensFile = path.join(process.cwd(), ".oauth-tokens.json"); } async loadSavedTokens(): Promise<void> { try { const data = await fs.readFile(this._tokensFile, "utf-8"); const saved = JSON.parse(data); this._tokens = saved.tokens; this._clientInformation = saved.clientInformation; console.log("✅ Loaded saved OAuth tokens"); } catch (error) { // No saved tokens, will need to authenticate console.log("ℹ️ No saved tokens found, will need to authenticate"); } } async saveTokensToFile(): Promise<void> { if (this._tokens && this._clientInformation) { await fs.writeFile( this._tokensFile, JSON.stringify( { tokens: this._tokens, clientInformation: this._clientInformation, }, null, 2 ) ); console.log("✅ Saved OAuth tokens to file"); } } get redirectUrl(): string { return this._redirectUrl; } get clientMetadata(): OAuthClientMetadata { return this._clientMetadata; } clientInformation(): OAuthClientInformation | undefined { return this._clientInformation; } async saveClientInformation( clientInformation: OAuthClientInformationFull ): Promise<void> { this._clientInformation = clientInformation; await this.saveTokensToFile(); } tokens(): OAuthTokens | undefined { return this._tokens; } async saveTokens(tokens: OAuthTokens): Promise<void> { this._tokens = tokens; await this.saveTokensToFile(); } redirectToAuthorization(authorizationUrl: URL): void { this._pendingAuthUrl = authorizationUrl.toString(); console.log("\n" + "=".repeat(80)); console.log("🔐 OAUTH AUTHENTICATION REQUIRED"); console.log("=".repeat(80)); console.log("\nPlease complete authentication by visiting:"); console.log("\n 👉 " + this._pendingAuthUrl); console.log("\nAfter authorizing, you'll be redirected to:"); console.log(" " + this._redirectUrl); console.log("\nThe server will automatically continue once authenticated."); console.log("=".repeat(80) + "\n"); } getPendingAuthUrl(): string | undefined { return this._pendingAuthUrl; } clearPendingAuth(): void { this._pendingAuthUrl = undefined; } async saveCodeVerifier(codeVerifier: string): Promise<void> { this._codeVerifier = codeVerifier; } async codeVerifier(): Promise<string> { if (!this._codeVerifier) { throw new Error("No code verifier saved"); } return this._codeVerifier; } }