Agent orchestration and execution layers connect autonomous AI agents to the DeFi and Web3 stack, letting them observe markets, call protocol actions, and coordinate off‑chain tooling. This topic covers the middleware and runtime changes—both off‑chain (MCP servers, kernels, integrations) and on‑chain (agent‑focused runtimes and VM upgrades)—that make practical, secure agentic workflows possible. As of 2026, two converging trends make this especially timely: richer on‑chain execution primitives (e.g., Sui VM upgrades that improve deterministic, performant smart‑contract execution) and emerging agent runtimes (e.g., Orbs Agentic) that codify multi‑step, policy‑driven behavior. Together these reduce friction for deploying agent logic that must combine on‑chain transactions with external data and tools. Key components and tools: MCP servers (Model Context Protocol) act as the orchestration fabric—examples include the Solana Agent Kit (LangChain‑ready connectors exposing 60+ Solana actions), Kiln’s MCP integrations for task tooling, n8n’s MCP server for natural‑language workflow control, and Playwright and Browser MCP servers for automated web interactions. Integration platforms like Pipedream provide broad API connectivity, while the MCP Toolbox for Databases handles secure, scalable DB access. Agent kernels such as Agent TARS demonstrate mounting MCP servers to create multimodal agent runtimes. Practical relevance: these layers enable automated DeFi use cases—position rebalancing, liquidation protection, cross‑protocol routing, and compliance checks—while centralizing observability, access control, and cost considerations. The dominant design is hybrid: lightweight on‑chain agents using upgraded VMs for settlement and state, orchestrated by off‑chain MCP servers that manage external APIs, browser automation, and databases. Developers should evaluate security, latency, and composability when assembling orchestration and execution stacks for production DeFi agents.