MCP vs webhooks
MCP (Model Context Protocol) and webhooks solve opposite halves of the same problem. MCP lets an AI agent reach out: call tools, query APIs, fetch context on demand. Webhooks let the outside world reach in: push an event to you the moment it happens. One is pull, the other is push, and agent systems increasingly need both.
What MCP does
MCP is an open protocol, introduced by Anthropic, that standardizes how AI applications connect to external tools and data. An MCP server exposes tools, resources, and prompts; a client like Claude, Cursor, or an agent framework connects to it and calls those tools during a conversation or task. The interaction model is request/response: the agent decides it needs something, makes a call, and gets an answer back.
That model covers a lot, but everything starts with the agent asking. An MCP server can't tap the agent on the shoulder because a payment failed or a build broke.
What webhooks do
A webhook is an HTTP POST that a service sends to a URL you registered, triggered by an event: a payment succeeded, a PR merged, an incident opened. The receiver doesn't ask; the sender pushes. That's what makes webhooks the standard for real-time notification between services, and why they beat API polling on both latency and wasted requests.
The cost is operational: receivers need a public endpoint, senders need retries and signatures, and both sides need observability when deliveries go missing.
The actual difference
Comparing "MCP vs webhooks" is really comparing interaction models, not competing standards:
| MCP | Webhooks | |
|---|---|---|
| Direction | Agent initiates (pull) | Event source initiates (push) |
| Shape | Request/response tool calls | One-way HTTP POST per event |
| Answers | "What do I need to know right now?" | "Something just happened" |
| Typical use | Agent queries a database, runs a search, files a ticket | Service notifies on payment, push, alert |
A stock-analysis agent uses MCP to fetch prices when you ask; a webhook is how it finds out a price alert fired at 3am. Neither replaces the other, the same way REST APIs never replaced webhooks.
Where they meet
The two combine in three ways, in increasing order of maturity.
Webhooks into agents. External events reach an agent through an MCP server that exposes them as tools. Since MCP servers usually run locally with no public URL, the standard pattern is a gateway that receives and verifies the events, with the MCP server polling it. How to build a webhook MCP server is a working walkthrough, and Claude Code Channels show the push variant for Claude Code specifically.
Agents firing webhooks. An MCP tool that POSTs a payload outward lets an agent notify Slack, trigger automations, or call back into your systems when it finishes something.
Webhooks inside the MCP spec. MCP became stateless in the 2026-07-28 release and gained a tasks extension for asynchronous work. The planned follow-up is webhook delivery for task results: an agent kicks off a long-running task, hands over a URL, and gets the result pushed hours later instead of holding a connection or polling. Our post on MCP going stateless explains why statelessness had to come first. Once that lands, MCP implementers inherit the classic webhook sender problems, retries, signing, and delivery observability among them, which is exactly the infrastructure Svix provides.
Frequently asked questions
Does MCP replace webhooks?
No. MCP standardizes how agents call tools and fetch context on demand; webhooks deliver events the moment they happen. They are complementary, and the MCP spec is itself adopting webhooks for asynchronous task results.
Can MCP push events to an agent?
Not in the core tool model, where the agent always initiates. Push exists at the edges: Claude Code Channels push notifications into a running session, and protocol-level webhook delivery for async tasks is on the MCP roadmap.
How does an AI agent receive webhooks today?
Through a gateway. Providers deliver to the gateway's public URL, it verifies signatures and stores events, and an MCP server exposes them to the agent as tools via polling. This avoids tunnels and signing-secret code on the agent side.