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FastMCP 4.1.4 adds rotating Redis credentials for tasks

Updated FastMCP

Summary

FastMCP 4.1.4 (October 26, 2026) supports rotating Redis credentials for tasks, excludes Redis 8.1.0 and fixes generated CLIs and mounted servers.

Tool
FastMCP
Category
MCP servers
Date
Open source
Yes
License
Apache-2.0
MCP
Yes
Pricing
Not stated in the sources we cited.
Sources

Prefect released FastMCP 4.1.4 on October 26, 2026, six days after 4.1.3. The fastmcp package reached PyPI the same morning. It is a fix release with one feature that matters to anyone running background tasks on managed Redis, plus one dependency change that can break an install.

Release facts

FactDetail
ProductFastMCP (Python)
Version4.1.4
Release dateOctober 26, 2026 (GitHub release and PyPI)
Previous release4.1.3, October 20, 2026
LicenseApache-2.0
Installpip install fastmcp==4.1.4 (Python 3.10 or later)

Check before upgrading

  • Keyring is no longer pulled in. The unused keyring dependency was removed. If you use a custom KeyringStore, install py-key-value-aio[keyring] yourself.
  • Redis 8.1.0 is excluded to keep task reconnection working.
  • Streaming credential providers (such as redis-entraid's) are rejected by TasksExtension until the Docket task backend can refresh them safely.

What changed

  • Rotating Redis credentials for tasks: tasks accept a redis-py credential provider that returns current credentials for each new connection. Providers survive cloning of task extensions.
  • Generated CLIs (fastmcp generate-cli) keep HTTP and SSE transports, empty arrays and parameters whose names collide with helper names, including tools with a json parameter.
  • Mounted servers honor session visibility and mounted_components_raise_on_load_error.
  • Client: a stale client context no longer closes a newer session, and StreamableHttpTransport forwards max_sse_event_size.
  • Auth and proxies: OAuth provider wrappers expose identity assertions, configured proxy headers replace forwarded ones regardless of case, and certifi is bumped to 2026.10.19.
  • Smaller fixes: audio paths map common extensions, OpenAPI operations with an empty success body get no output schema, and fastmcp install creates a missing or empty MCP config file.

Questions

Should I upgrade? Yes if you run FastMCP tasks on Redis with short-lived credentials, or if you ship generated CLIs. Check the keyring and Redis 8.1.0 notes first.

Is the certifi bump enough after the October CA incident? No. The 4.1.3 notes say FastMCP 4 uses system trust by default and that you also need to update operating-system, container and installer trust stores. Upgrading FastMCP alone is not enough.

What about 4.2? GitHub has a v4.2.0a1 prerelease from October 27. Agent Radar covers stable releases only.

More: the FastMCP hub, the MCP servers category, and this week's Playwright MCP v0.0.84.

Alternatives

FastMCP compared with its alternatives
ToolLicensePricing note
FastMCPThis launchPrefect's Apache-2.0 Python framework for building MCP servers, clients and apps; version 4 targets the 2026-07-28 MCP protocol revision.
Apache-2.0Apache-2.0 and free to install from PyPI.
Model Context Protocol ServersGitHub repository of Model Context Protocol servers, shipped as npm and PyPI packages such as filesystem and git.
—Not stated

Questions

What is FastMCP?

A Python framework from Prefect for MCP servers, clients and interactive apps. You declare a tool as a decorated Python function, and FastMCP generates the schema, validation and docs and handles transports and auth.

Is FastMCP the same as the MCP Python SDK?

No. The README says FastMCP 1.0 was folded into the official MCP Python SDK in 2024, and the standalone project kept going. FastMCP 4, stable since August 31, 2026, is built on MCP Python SDK v2 and the 2026-07-28 protocol revision.

How do I install FastMCP?

pip install fastmcp. PyPI lists version 4.1.4 (October 26, 2026), Apache-2.0, requiring Python 3.10 or later.

Filed on Agent Radar. Claims in this note are limited to the sources above.