d63d6370c0
The generated /etc/nginx/overrides/server.d/mcp-locations.conf used a plain proxy_pass target (e.g. `proxy_pass http://penpot-mcp:4402;`) where $PENPOT_MCP_URI/$PENPOT_MCP_URI_WS are shell variables substituted once by envsubst in nginx-entrypoint.sh at container startup, not nginx variables. nginx resolves a literal proxy_pass hostname once when the config loads and never re-checks it, so the existing `resolver 127.0.0.11 valid=10s;` directive in overrides/http.d/resolvers.conf has no effect on these three locations - it only applies to nginx variables evaluated per-request. In multi-container deployments where the penpot-mcp container restarts or is recreated independently of penpot-frontend (image update, OOM, orchestrator reschedule), it gets a new IP from Docker's/the orchestrator's DNS, and the frontend's nginx keeps forwarding to the old, now-dead address until penpot-frontend itself is restarted. This surfaces to users as `wss://<host>/mcp/ws` failing to connect from the browser after enabling the MCP plugin, with `connect() failed (111: Connection refused)` in the frontend's nginx logs. Route each location through a `set $var ...; proxy_pass $var;` pair so proxy_pass evaluates a real nginx variable, letting the pre-existing resolver directive re-resolve penpot-mcp within its 10s TTL instead of caching the address for the container's lifetime. For /mcp/stream and /mcp/sse, the set value also appends $is_args$args explicitly: when proxy_pass targets a variable AND that variable's value includes a URI/path component, nginx does not automatically forward the original request's query string the way it does for a static proxy_pass target - it must be appended by hand, or the userToken query parameter used for multi-user authentication is silently dropped before reaching the MCP server. /mcp/ws has no path component in its target so it isn't affected by this and needed no such change. Verified locally: force-recreated the penpot-mcp container onto a different IP while leaving penpot-frontend untouched; the /mcp/ws WebSocket upgrade kept returning 101 Switching Protocols throughout, both immediately and after the resolver's TTL window. Separately verified /mcp/stream: a POST with ?userToken=... now shows up server-side as userTokenFp=<redacted first 8 chars> instead of <none>, and an actual MCP client (Claude Code) using this proxy can now call authenticated tools like execute_code successfully. Signed-off-by: Jules LaPrairie <jules@lucidbox.ca>
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Penpot is the open-source design platform for teams that build digital products at scale.
Penpot’s key strength lies in giving you full ownership of your design infrastructure. Built on open source and designed for self-hosting, it puts teams in complete control of their design environment supporting strict compliance and governance requirements. Whether used in the browser or deployed on your own servers, Penpot works with open standards like SVG, CSS, HTML, and JSON.
Real-time collaboration strengthens this foundation, helping teams scale and bring design closer to the product through top-tier capabilities. Additionally, developers feel at home using Penpot, because design is expressed as code, enabling a direct translation and shipping products faster.
Best-in-class native Design Tokens provide a single source of truth between design and development. They ensure consistency, improve collaboration, and make it easier to manage complex design systems.
The MCP server takes it further by enabling multi-directional workflows between design and code. A powerful open API and plugin system makes the workspace programmable, enabling automation, AI-driven workflows, and integrations with the tools and systems you already use.
With CSS Grid and Flex Layout, teams can design responsive interfaces that behave like real code from the start.
Combined, these features turn Penpot into a full-stack design platform for building scalable design systems and fully integrated product development processes.
If your organization is scaling and needs extra support, we’re here to help. Talk to us
Table of contents
Why Penpot
Penpot connects design, code, and AI workflows through a code-based approach, making designs readable by developers and AI via the MCP server. This approach helps teams ship what’s actually designed and manage design systems at scale with powerful design tokens. As a self-hosted, open-source and real-time collaboration platform, Penpot offers full flexibility, security, and ownership without vendor lock-in. Learn more about why Penpot is the platform for your team.
Plugin system
Penpot plugins let you expand the platform's capabilities, give you the flexibility to integrate it with other apps, and design custom solutions.
Designed for developers
Penpot was built to serve both designers and developers and create a fluid design-code process. You have the choice to enjoy real-time collaboration or play "solo".
Inspect mode
Work with ready-to-use code and make your workflow easy and fast. The inspect tab gives instant access to SVG, CSS and HTML code.
Integrations
Penpot offers integration into the development toolchain, thanks to its support for webhooks and an API accessible through access tokens.
Building Design Systems: design tokens, components and variants
Penpot brings design systems to code-minded teams: a single source of truth with native Design Tokens, Components, and Variants for scalable, reusable, and consistent UI across projects and platforms.
Getting started
Penpot is the only design & prototype platform that is deployment agnostic. You can use it in our SAAS or deploy it anywhere.
Learn how to install it with Docker, Kubernetes, Elestio or other options on our website.
Community
We love the Open Source software community. Contributing is our passion and if it’s yours too, participate and improve Penpot. All your designs, code and ideas are welcome!
Want to go a step further? Become a Penpot Ambassador and help grow the Penpot community in your region while contributing to a global, open design ecosystem.
If you need help or have any questions; if you’d like to share your experience using Penpot or get inspired; if you’d rather meet our community of developers and designers, join our Community!
Categories include:
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Code of Conduct
Anyone who contributes to Penpot, whether through code, in the community, or at an event, must adhere to the code of conduct and foster a positive and safe environment.
Contributing
Any contribution will make a difference to improve Penpot. How can you get involved?
Choose your way:
- Create and share Libraries & Templates that will be helpful for the community.
- Invite your team to join.
- Give this repo a star and follow us on Social Media: Mastodon, Youtube, Instagram, Linkedin, Peertube, X and BlueSky.
- Participate in the Community space by asking and answering questions; reacting to others’ articles; opening your own conversations and following along on decisions affecting the project.
- Report bugs with our easy guide for bugs hunting or GitHub issues.
- Become a translator.
- Give feedback: Email us.
- Contribute to Penpot's code: Watch this video by Alejandro Alonso, CIO and developer at Penpot, where he gives us a hands-on demo of how to use Penpot’s repository and make changes in both front and back end.
To find (almost) everything you need to know on how to contribute to Penpot, refer to the contributing guide.
Resources
You can ask and answer questions, have open-ended conversations, and follow along on decisions affecting the project.
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License
This Source Code Form is subject to the terms of the Mozilla Public
License, v. 2.0. If a copy of the MPL was not distributed with this
file, You can obtain one at http://mozilla.org/MPL/2.0/.
Copyright (c) KALEIDOS INC Sucursal en España SL
Penpot is a Kaleidos’ open source project