/**
 * Ed25519 Signature Verification for HTTP Message Signatures
 * Implements proper cryptographic verification for ChatGPT and other agents
 *
 * Based on RFC 9421 (HTTP Message Signatures) and ChatGPT's implementation
 * Reference: https://help.openai.com/en/articles/9785974-chatgpt-user-allowlisting
 */
/**
 * Signature verification result
 */
interface SignatureVerificationResult {
    isValid: boolean;
    agent?: string;
    keyid?: string;
    confidence: number;
    reason?: string;
    verificationMethod: 'signature' | 'none';
}
/**
 * Verify HTTP Message Signature for AI agents
 */
declare function verifyAgentSignature(method: string, path: string, headers: Record<string, string>): Promise<SignatureVerificationResult>;
/**
 * Quick check if signature headers are present (for performance)
 */
declare function hasSignatureHeaders(headers: Record<string, string>): boolean;
/**
 * Check if this is a ChatGPT signature based on headers
 */
declare function isChatGPTSignature(headers: Record<string, string>): boolean;

export { type SignatureVerificationResult, hasSignatureHeaders, isChatGPTSignature, verifyAgentSignature };