FastMCP 3.0

The fast, Pythonic way to build MCP servers and clients

Open Source

Developer Tools

Artificial Intelligence

Context drift is what kills most agents. It is a clean way to control what agents see instead of flooding them.

Hi,

I came across FastMCP and spent some time with your getting-started page.

You’ve built a very solid technical foundation, the Pythonic examples and documentation structure clearly speak to devs who want to ship MCP servers. But as it stands, the landing reads like documentation rather than a product pitch. There’s no concise value proposition up front or outcome-driven benefits that immediately answer: why should I care right now and what will I be able to do after 5 minutes? This makes it easy for first-time visitors to bounce before they even see the value.

For a dev-centric tool like this, a stronger hero message focused on concrete outcomes (speed to production, save hours of boilerplate, works with top AI stacks) and a couple of action-oriented CTAs would significantly improve clarity and conversion, especially on Product Hunt where attention is short and competition is high.

Happy to run a brief landing audit and suggest precise copy improvements that keep your technical voice but boost engagement and conversion. If you’re interested in a short paid audit, just let me know.

Best,

Paul

Sounds interesting. We’re actually building an AI app in Python, I’ll show your product to the team…

Built-in version control is solid—iterating on apps feels like having a time machine. But we suggest adding automatic prompts for change impacts, like telling me "which existing workflows will be affected by this modification," to prevent accidental mistakes.

The permission control is nicely detailed—managing tool access feels like handing out different keys to colleagues. But we hope a "temporary permission" feature can be added to avoid repeated configurations during short-term cross-department collaboration.

Real-time hot reloading and status tracking are super thoughtful! You don’t have to restart the service when modifying code—it’s like having an assistant refreshing things in sync. That said, troubleshooting would be much more intuitive if the task log interface was visualized on a timeline.

The integrated tool experience is so seamless—it’s like a universal adapter that lets you plug in all kinds of data sources and use them right away. But it’d be even easier for newbies to build apps if there were pre-built templates for common use cases, like an automatic weekly report generator.

We've been adopters of FastMCP since the early days at Noodle Seed! - Super excited to see the launch of version 3.0!

@jlowin jlowin — “context applications” (state + ACL + long tasks + observability) is exactly where MCP gets painful at scale: multi-source fan-out + stale context + non-idempotent tool runs.

Best-practice: treat every tool call as a versioned contract (Pydantic schemas + semver), persist state as an event log (so you can replay/debug), and add distributed tracing with correlation IDs across sources/steps.

Q: is state storage pluggable (Redis/Postgres) with resumable long-jobs, and do you support per-user ACL down to field-level redaction in composed contexts? 🔥

love the shift to stateful context apps over just dumb tool servers. does this replace the need for LangGraph in simpler agents?

Can you tell a little bit more about what you do in version 3, please? How does it differ from 2?

Hey Chris, that line about the real challenge being delivering the right info at the right time, not implementing the protocol, is a good reframe. Was there a specific project where you had MCP working technically but the agent still wasn’t getting what it needed when it needed it?

Love the "context applications" framing - MCP isn’t hard, relevance is.
Curious what you’ve seen as the biggest source of pain in practice: state across sessions, access control, or debugging/observability once you have multiple sources in the loop?
Also - do you have an opinionated default for tracing tool calls end-to-end (so people don’t live in logs)?

Congrats on the launch — love how FastMCP is pushing MCP beyond “tool servers” into real context apps with state, access control, and observability built in.