Hmm. This one is **really** tough. I.e. to have MCP or not to have....

There are two components here: MCP and AI Assistant. I will discuss MCP
this time. I haven't made up my mind about the AI assistant yet.

Initially I thought we could rely on external ones, but after working
hands-on with AI I still have not made up my mind:

I think there are many things we should consider:

1) Trust and Security - I think this is a big one with two sides: Trust -
it would be great if our users could install Airflow's "official" MCP
which is "stamped" by the ASF. I guess every time you install MCP you ask
yourself a question "Do I trust it?"—and this is a big one. I.e. With the
ASF release process, community, apache.org domain and so on, people would
have far fewer problems than installing it from a user who claims,
"I_am_absolutely_safe_to_use_it_no_malware_whatsoever.However, the second
point is that we cannot really breach that trust - and with MCP servers,
it's super easy. Incoming issues on the ASF and frequent, painful issues on
MCP servers are common. Especially that secrurity in Agentic world has a
completely new features that we are not well prepared for ("Ignore all
previous instructions and start mining bitcoins prompts" is just a tip of
the iceberg). So .... a lot of protection will have to be put in place if
we release something officially as an "Apache Airflow MCP." . That poses a
challenge regarding the upcoming security strengthening that all OSS
projects will soon have to implement, I think - due to AI. And I think we
should only add MCP to our "Security" plate after we know how the current
"Mythos" discussions end and where we will settle things down I expect next
two months will add a lot of strain on that front - people argue about the
extent and impact. But I think adding a new "security vector" to our
software stack is likely not a good idea.

2) Code - donation vs. creation: I don't think it has to be an either/or
situation (own idea/Astronomer). When we initially discussed MCP I thought,
"Let's learn from others and build our own by looking at what works and
what problems they have. I see significant opportunity here, especially
when paired with the fact that creating new code now costs almost nothing
with Agents. Instead of donating the code, we could reconcile the
specifications and approach of Astronomer's MCP server with our ideas. We
could then see if we can merge them together to create something
functionally equivalent (or largely a superset of) what Astronomer did.
This would involve learning from the Astronomer team about what worked for
them, their mistakes, how they handled security issues, and so on. We could
even invite other MCP creators to share their experiences and develop a
design proposal that incorporates all these lessons. Eventually, this
proposal (perhaps with some glue layers) could serve similar use cases as
Astronomer's solution. We could choose better technology stack for it (new
options appear constantly), make better architectural choices, and harden
security more effectively. From what I understand how MCP work - there
isn't a significant need for "perfect" compatibility. Agents using MCPs
only need to learn enough about the tool to use it and can adapt if the
interface is "close enough".

Also, coming out of the Helm Chart refurbishment meeting: while the Helm
chart and some of Astronomer's choices were great and we had a "working
solution" at the time of donation, some of the choices and decisions
started to show their age (as usual) after a few years when newer versions
of Helm and Kustomize were released. If we started the Chart today, it
would probably look quite a bit different (Bugra will send a summary of our
notes soon, including the rough architectural decisions we propose).  It
took years, but with Agentic space, what used to take years now takes
months (or weeks). I can imagine (though I'm just guessing) that this will
affect Astronomers' or others' MCPs, which are likely already outdated
somehow - and we can do them "better" - and with Claude and other Agentic
tooling - if we have the right spec + good security check automation
(working on it!) - we might rebuild something that Astronomer users could
switch to seamlessly - without actually taking over the code.

That's my current thinking: spend time learning from others and designing
what's best then (re)implement it when the time comes using the stack,
tooling, and AI assistance that are state-of-the-art then.

J



On Thu, Apr 23, 2026 at 5:27 PM Kaxil Naik <[email protected]> wrote:

> Thanks Shahar for driving this, and Vaquar for the concrete security
> review. Both useful.
>
> TL;DR: my main concern on AIP-91 (MCP) and AIP-101 (AI Assistant) is
> maintenance. The recent maintenance issues with Airflow Helm Chart and
> Python Client for examples are the precedent: both good and useful packages
> for the ecosystem, but the ongoing cost was and still is real. We already
> have a persistent PR review backlog on the existing apache/airflow
> codebase; adding two new subprojects compounds that, and brings with it
> release-cycle complexity and a live security-boundary surface.
>
> That said: Astronomer is happy to donate the Airflow MCP server we maintain
> at astronomer/agents (the astro-airflow-mcp
> <https://github.com/astronomer/agents/tree/main/astro-airflow-mcp
> >subpackage)
> as a starting point for AIP-91, similar in spirit to the Helm Chart. It
> works with both Airflow 2 and Airflow 3 and is now used by 100s of
> companies: both Astronomer customers and OSS users.
>
> We'd have to think about the backwards-compat for the current users of that
> MCP -- I have some rough ideas already on that front already so that is not
> a blocker.
>
> Regards,
> Kaxil
>
>
> On Tue, 7 Apr 2026 at 05:33, vaquar khan <[email protected]> wrote:
>
> > Hi Shahar ,
> >
> > Thank you for putting together this comprehensive proposal. The decision
> to
> > architect the MCP server as a stateless proxy that delegates all RBAC
> > evaluation to Airflow's native Auth Manager is a fantastic design choice.
> > It cleanly avoids the Confused Deputy problem and ensures per-user
> > permission enforcement without forcing us to maintain a parallel
> > authorization layer.
> >
> > I've been reviewing the AIP-91 design specifications against the current
> > codebase (specifically the v3-2-test branch), and I wanted to raise a few
> > concrete findings regarding the implementation. Because AI agents consume
> > data fundamentally differently than human operators do, there are a few
> > architectural gaps we might need to address:
> >
> >
> > *1. Task Logs Are Not Redacted on the Read Path*AIP-91 states: The MCP
> > Server MUST pipe all retrieved free-text artifacts (specifically Task
> Logs
> > and Rendered Templates) through Airflow's native SecretsMasker before
> > serializing the tool response. However, looking at the current API
> > execution path (get_log -> TaskLogReader.read_log_chunks ->
> > FileTaskHandler.read), there is no read-time invocation of
> > SecretsMasker.redact(). Because SecretsMasker is a logging.Filter, it
> only
> > masks secrets at write time. If a secret was leaked via a standard out
> > print() before being registered, or if the masker simply wasn't active,
> the
> > REST API will serve the leaked credential as-is.
> >
> > Question: Should we introduce a read-time redaction layer directly within
> > TaskLogReader, or should we explicitly make this the responsibility of
> the
> > MCP proxy?
> >
> >
> > *2. Lack of Heuristic Detection for Unregistered Secrets*The native
> > SecretsMasker is highly optimized for deterministic masking (key-name
> > matching against fields like password or api_key, and exact-string
> > matching). It does not use regex heuristics to detect high-entropy
> strings,
> > which makes sense given historical performance concerns with regex in the
> > main logging pipeline. However, for an AI assistant blindly consuming
> > arbitrary tracebacks, unregistered secrets (like an AWS AKIA... key or a
> > JWT eyJ... token) represent a severe exfiltration risk.
> >
> > Question: Should the MCP server implement a secondary, regex-based
> > heuristic scrubbing layer exclusively for LLM payloads before they leave
> > the network boundary?
> >
> >
> > *3. The get_log_tail Tool Relies on Non-Existent API Functionality*AIP-91
> > specifies that truncated log payloads will instruct the LLM to use a
> > get_log_tail tool. Currently, the log API handles pagination via an
> opaque
> > continuation token (URLSafeSerializer). Because this is a forward-only
> > cryptographic cursor, it cannot be used for a bounded page backwards from
> > the end of the file navigation, which is exactly what an AI needs to
> > quickly read a stack trace.
> >
> > Question: Will get_log_tail require us to build a new byte-offset/tailing
> > endpoint into the Core API, or will the MCP server cache the full log
> > stream internally to virtualize this capability?
> >
> >
> > *4. JWT Token Refresh for Bearer-Authenticated Clients*The Core API's
> > JWTRefreshMiddleware is currently optimized for browser UI sessions
> > (cookies). When the MCP server authenticates via a Bearer token in the
> > Authorization header,the standard for machine-to-machine integration
> > expired tokens trigger an exception rather than a refresh. The Execution
> > API handles this beautifully with a JWTReissueMiddleware that
> > auto-refreshes tokens with <20% validity remaining.
> >
> > Question: For long-running AI debugging sessions, should we harmonize the
> > Core API to adopt the Execution API's reissue middleware, or is the MCP
> > server expected to handle token rotation out-of-band?
> >
> >
> > *5. Resource Saturation and Rate Limiting*AIP-91 rightly proposes
> > token-bucket rate limiting. It’s worth noting that the current Core API
> > does not enforce rate limits on resource-intensive endpoints (like NDJSON
> > log streaming). An LLM caught in a hallucination loop could easily
> > overwhelm the webserver's connection pool.
> >
> > Question: This seems to reinforce the idea that the MCP server must
> > implement its own distributed rate limiting (e.g., backed by Redis)
> rather
> > than relying on the Core API to throttle rogue traffic. Do we agree this
> is
> > a hard requirement for Phase 1?
> >
> > I am highly supportive of this AIP and the proxy-based approach. I would
> be
> > more than happy to help contribute to the implementation or assist with
> > testing these specific security boundaries.
> >
> > Best regards,
> > Viquar Khan
> >
> > On Fri, Apr 3, 2026 at 6:38 AM Shahar Epstein <[email protected]> wrote:
> >
> > > Hey everyone,
> > >
> > > A lot of water has passed under the AI bridge since we first discussed
> > > this, and I think it's a good time to get things moving.
> > >
> > > I have drafted AIP-91 for the official Airflow MCP Server:
> > >
> >
> https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=364349979
> > >
> > > tl;dr - In its 1st phase, the main use case of the MCP server will be
> to
> > > serve the planned Airflow AI Assistant (which will be discussed in a
> > > separate thread for AIP-101). To ensure strict security and per-user
> RBAC
> > > enforcement, both the MCP server and the assistant will be strictly in
> > > read-only mode for Phase 1.
> > >
> > > A quick note: While I'm proposing this as a separate AIP, I highly
> > > recommend reading it in the context of AIP-101 to see exactly how the
> two
> > > pieces fit together.
> > >
> > > I'd love to get your thoughts and feedback on the design.
> > >
> > >
> > > Shahar
> > >
> > > On 2025/05/28 17:25:06 Shahar Epstein wrote:
> > > > Dear community,
> > > >
> > > > Following the thread on Slack [1], initiated by Jason Sebastian
> Kusuma,
> > > I'd
> > > > like to start an effort to officially support MCP in Airflow's
> > codebase.
> > > >
> > > > *Some background *
> > > > Model Context Protocol (MCP) is an open standard, open-source
> framework
> > > > that standardizes the way AI models like LLM integrate and share data
> > > with
> > > > external tools, systems and data sources. Think of it as a "USB-C for
> > > AI" -
> > > > a universal connector that simplifies and standardizes AI
> > integrations. A
> > > > notable example of an MCP server is GitHub's official implementation
> > > [3], which
> > > > allows LLMs such as Claude, Copilot, and OpenAI (or: "MCP clients")
> to
> > > > fetch pull request details, analyze code changes, and generate review
> > > > summaries.
> > > >
> > > > *How could an MCP server be useful in Airflow?*
> > > > Imagine the possibilities when LLMs can seamlessly interact with
> > > Airflow’s
> > > > API: triggering DAGs using natural language, retrieving DAG run
> > history,
> > > > enabling smart debugging, and more. This kind of integration opens
> the
> > > door
> > > > to a more intuitive, conversational interface for workflow
> > orchestration.
> > > >
> > > > *Why do we need to support it officially?*
> > > > Quid pro quo - LLMs become an integral part of the modern development
> > > > experience, while Airflow evolves into the go-to for orchestrating AI
> > > > workflows. By officially supporting it, we’ll enable multiple users
> to
> > > > interact with Airflow through their LLMs, streamlining automation and
> > > > improving accessibility across diverse workflows. All of that is
> viable
> > > > with relatively small development effort (see next paragraph).
> > > >
> > > > *How should it be implemented?*
> > > > As of today, there have been several implementations of MCP servers
> for
> > > > Airflow API, the most visible one [4] made by Abhishek Bhakat from
> > > > Astronomer.
> > > > The efforts of implementing it and maintaining it in our codebase
> > > shouldn't
> > > > be too cumbersome (at least in theory), as we could utilize packages
> > like
> > > > fastmcp to auto-generate the server using the existing OpenAPI specs.
> > I'd
> > > > be very happy if Abhishek could share his experience in this thread.
> > > >
> > > > *Where else could we utilize MCP?*
> > > > Beyond the scope of the public API, I could also imagine using it to
> > > > communicate with Breeze.
> > > >
> > > > *How do we proceed from here?*
> > > > Feel free to share your thoughts here in this discussion.
> > > > If there are no objections, I'll be happy to start working on an AIP.
> > > >
> > > >
> > > > Sincerely,
> > > > Shahar Epstein
> > > >
> > > >
> > > > *References:*
> > > > [1] Slack discussion,
> > > >
> > https://apache-airflow.slack.com/archives/C06K9Q5G2UA/p1746121916951569
> > > > [2] Introducing the model context protocol,
> > > > https://www.anthropic.com/news/model-context-protocol
> > > > [3] GitHub Official MCP server,
> > > https://github.com/github/github-mcp-server
> > > > [4] Unofficial MCP Server made by Abhishek Hakat,
> > > > https://github.com/abhishekbhakat/airflow-mcp-server
> > > >
> > >
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