# x0 Protocol > Autonomous agent payment infrastructure on Solana — policy enforcement, confidential transfers, escrow, reputation, and zero-knowledge proof verification. ## Docs - [x0 Protocol](https://docs.x0protocol.dev/index.md): Autonomous agent payment infrastructure on Solana — policy-enforced transfers, conditional escrow, on-chain reputation, and zero-knowledge proof verification. - [Resources](https://docs.x0protocol.dev/links/resources.md): External documentation, references, and academic papers relevant to the x0 protocol. - [Architecture](https://docs.x0protocol.dev/protocol/architecture.md): System architecture, program interactions, and design principles of the x0 protocol. - [Solana Actions (Blinks)](https://docs.x0protocol.dev/protocol/blinks.md): Human-in-the-loop approval workflows using Solana Actions (Blinks) for high-risk agent operations. - [Constants Reference](https://docs.x0protocol.dev/protocol/constants.md): Complete reference of all protocol constants used across x0 on-chain programs. - [Error Codes](https://docs.x0protocol.dev/protocol/errors.md): Complete reference of all error codes across the x0 protocol, organized by program and category. - [x0-escrow](https://docs.x0protocol.dev/protocol/escrow.md): Conditional escrow with 7-state machine, dispute resolution, arbiter support, and auto-release timeout. - [Events Reference](https://docs.x0protocol.dev/protocol/events.md): Complete reference of all protocol events emitted by x0 on-chain programs. - [x0-guard](https://docs.x0protocol.dev/protocol/guard.md): Policy enforcement layer — transfer hook validation, rolling window spend limits, whitelist verification, and privacy modes. - [Programs Overview](https://docs.x0protocol.dev/protocol/programs.md): Summary of all x0 on-chain programs, their purposes, and deployment addresses. - [x0-registry](https://docs.x0protocol.dev/protocol/registry.md): Agent discovery service with capability metadata, endpoint registration, and lifecycle management. - [x0-reputation](https://docs.x0protocol.dev/protocol/reputation.md): On-chain reputation oracle with weighted scoring, temporal decay, and cross-program integration. - [x0-token](https://docs.x0protocol.dev/protocol/token.md): Token-2022 mint management with TransferFee, TransferHook, and ConfidentialTransfer extensions. - [x0-wrapper](https://docs.x0protocol.dev/protocol/wrapper.md): 1:1 USDC-backed stablecoin wrapper with timelocked governance, reserve monitoring, and emergency controls. - [HTTP 402 Protocol](https://docs.x0protocol.dev/protocol/x402.md): Machine-to-machine payment flow using HTTP 402 Payment Required for autonomous agent commerce. - [x0-zk-proofs](https://docs.x0protocol.dev/protocol/zk-proofs.md): Off-chain WASM library for client-side zero-knowledge proof generation using solana-zk-token-sdk. - [x0-zk-verifier](https://docs.x0protocol.dev/protocol/zk-verifier.md): On-chain Groth16 zero-knowledge proof verification for confidential transfers over the Ristretto255 curve. - [X0Client](https://docs.x0protocol.dev/sdk/client.md): Complete API reference for the main X0Client class — the unified entry point for all protocol operations. - [Confidential Transfers](https://docs.x0protocol.dev/sdk/confidential.md): Privacy-preserving token transfers using ElGamal encryption and zero-knowledge proofs. - [Escrow](https://docs.x0protocol.dev/sdk/escrow.md): Build agent-to-agent payment escrows with the EscrowManager class. - [Installation](https://docs.x0protocol.dev/sdk/installation.md): Install and configure the x0 Protocol SDK for your TypeScript project. - [Policy Management](https://docs.x0protocol.dev/sdk/policy.md): Configure and manage agent spending policies using the PolicyManager class. - [Quick Start](https://docs.x0protocol.dev/sdk/quickstart.md): Get up and running with the x0 Protocol SDK in 5 minutes. - [Registry & Reputation](https://docs.x0protocol.dev/sdk/registry-reputation.md): Agent discovery with RegistryManager and trust scoring with ReputationManager. - [Token Operations](https://docs.x0protocol.dev/sdk/token.md): Manage the x0-USD token mint, transfer fees, and Token-2022 extensions using TokenClient. - [Types Reference](https://docs.x0protocol.dev/sdk/types.md): Complete reference of all TypeScript interfaces, enums, and type aliases exported by the SDK. - [Utilities](https://docs.x0protocol.dev/sdk/utilities.md): Fee calculation, PDA derivation, hashing, Merkle trees, Bloom filters, and timestamp helpers. - [Wrapper (x0-USD)](https://docs.x0protocol.dev/sdk/wrapper.md): Deposit USDC, mint x0-USD, redeem, and manage governance using the WrapperClient. - [x402 & Blinks](https://docs.x0protocol.dev/sdk/x402-blinks.md): HTTP 402 payment protocol and Solana Actions (Blinks) for human-in-the-loop approval. - [ZK Verifier](https://docs.x0protocol.dev/sdk/zk-verifier.md): Verify zero-knowledge proofs on-chain using the ZkVerifierClient. - [Attack Vectors](https://docs.x0protocol.dev/security/attack-vectors.md): Known attack vectors, mitigations, and residual risks for the x0 protocol. - [Audit Status](https://docs.x0protocol.dev/security/audit.md): Current audit status, known findings, and security checklist for the x0 protocol. - [Protocol Invariants](https://docs.x0protocol.dev/security/invariants.md): Formal invariants that must hold across all x0 protocol operations. - [Threat Model](https://docs.x0protocol.dev/security/threat-model.md): Adversary model, trust assumptions, and security boundaries of the x0 protocol. ## OpenAPI Specs - [openapi](https://docs.x0protocol.dev/api-reference/openapi.json) ## Optional - [GitHub](https://github.com/x0-project/x0-01) - [Whitepaper](https://raw.githubusercontent.com/0xTnxl/x0/main/whitepaper.pdf)