6 ms·

Show HN: A MCP server and client implementing the latest spec

72 points by init0 1y ago

baalimago 1y ago
The fact that this is an achievement is a testament to how bloated the MCP protocol/spec already is. Will be interesting to see how many days it'll take before the implementation no longer is the latest
- tomashubelbauer 1y ago
  I don't disagree, but the first sentence of your post happens to be true for very many specs/protocols I know of and have implemented in the past. And it is not just communication protocols. Take PDF for example. The world practically runs on it, yet the file format is horrid. The real standard seems to be that standards are bloated by default.
  - Spivak 1y ago
    Right but MCP is a brand new protocol which is at its core JSON-RPC formatted messages and a few verbs. It doesn't actually do much. The main things are tool definitions which is just a JSON schema describing a function call and resources which a is a wisp of a filesystem.
    - tomashubelbauer 1y ago
      Fair, thought I have a feeling MCP will actually grow to do much more. I wouldn't disagree with the sentiment that it is too bloated too soon, but I also feel like it is destined to be bloated, because the technology it is targeting is sort of a moving target itself. Of course with proper versioning, this is easeable, deprecate stuff that turned out to be the wrong turn and cut major versions or introduce extensions to the protocol when new stuff is on the scene, but then you're liable to find yourself in an XMPP-style situation where no one implements the standard and extensions wholly, because it is so complex.
manojlds 1y ago
Almost no client, including Claude Dekstop, implements Sampling. I was so excited to see if I can create a server that used sampling and quickly figured out I can't use it anywhere. Funnily Windsurf hangs forever if you use sampling.
- auggierose 1y ago
  Yes, no sampling, last time I tried a few weeks ago. Have you tried with the latest Claude Desktop (0.10.14)?
- ericol 1y ago
  I've been thinking about this ever since I heard that is defined in the protocol. I think the biggest issue is that it can create loops in the flow of programs that would burn through usage quotas pretty fast. It could also allow for "impersonating" the client what opens up a lot of possibilities. But yeah, the fact that Claude doesn't even implement this is... telling.
  - auggierose 1y ago
    Yeah, that is the reason it is not there, I guess, you could then really implement anything just with a flat rate.
- disintegrator 1y ago
  VS Code seems to be working on it https://www.epicai.pro/using-mcp-sampling-in-vs-code-insiders-dd12d https://www.epicai.pro/using-mcp-sampling-in-vs-code-insider...
- esafak 1y ago
  For those unfamiliar with the term: "Sampling is a powerful MCP feature that allows servers to request LLM completions through the client, enabling sophisticated agentic behaviors while maintaining security and privacy." https://modelcontextprotocol.io/docs/concepts/sampling https://modelcontextprotocol.io/docs/concepts/sampling
jamesblonde 1y ago
Protocol version in the readme is Full MCP 2025-03-26 specification support in the code it is "protocolVersion": "2024-11-05" https://github.com/hemanth/paws-on-mcp/blob/main/src/mcp_cli_client.py#L46 https://github.com/hemanth/paws-on-mcp/blob/main/src/mcp_cli...
- cfors 1y ago
  The README is 100% just autogenerated by Claude. It looks like every README generated from these tools. Can’t speak for the code since I haven’t peaked into it
  - jamesblonde 1y ago
    I thought it was a bit verbose - lots of repetition. I didn't realize how extensive claude/cursor generated READMEs were.
  - owebmaster 1y ago
    The README is a great overview of the MCP features. This is terribly derisive.
jhosft 1y ago
That README.md is so vibed with all the emojis and self-proofed comments. One day we’re going to look back on code written in June 2025 and laugh. The code works, but man does Claude 4 pump itself up.
- deleted 1y ago
  [deleted]
- esafak 1y ago
  The median code base it is trained on must be like that.
  - hammyhavoc 1y ago
    University student work y'say?
- hammyhavoc 1y ago
  > The code works Need a phat asterisk after it.
LeonidBugaev 1y ago
It does not implement the Auth :) (mcp auth is terrible btw)
- seanobannon 1y ago
  I couldn’t find any great examples of MCP auth, so made this demonstrate an oauth flow recently - https://github.com/OBannon37/chatgpt-deep-research-connector-example https://github.com/OBannon37/chatgpt-deep-research-connector...
- WXLCKNO 1y ago
  For my app I'm bypassing MCP auth and doing the regular oauth2 flow to connect users to external apps. Then I pass the stored oauth token directly to my (private) MCP servers alongside a bearer token.
cranberryturkey 1y ago
also checkout @profullstack/mcp-server on npm
pcwelder 1y ago
Tool annotations are missing. (Are they of any use though?)
welanes 1y ago
This guide may be useful for anyone interested in building their own spec-compliant MCP server: https://simplescraper.io/blog/how-to-mcp https://simplescraper.io/blog/how-to-mcp. Albeit, it's a few weeks old so already in need of an update!
josephg 1y ago
What is MCP? I’ve never heard of it.
- esafak 1y ago
  Model Context Protocol. The standard for interfacing LLMs with tools. https://modelcontextprotocol.io/ https://modelcontextprotocol.io/
- buonu 1y ago
  Aka controller or middleware Bit of software between client and backend model to model client requests to It can look like Anthropics model or it can be your own. It’s verbose semantics to describe a little bit of source code. Obfuscation of simple loops and scripts is software industries main product

72 points by init0 1y ago

The fact that this is an achievement is a testament to how bloated the MCP protocol/spec already is. Will be interesting to see how many days it'll take before the implementation no longer is the latest

tomashubelbauer 1y ago
I don't disagree, but the first sentence of your post happens to be true for very many specs/protocols I know of and have implemented in the past. And it is not just communication protocols. Take PDF for example. The world practically runs on it, yet the file format is horrid. The real standard seems to be that standards are bloated by default.
- Spivak 1y ago
  Right but MCP is a brand new protocol which is at its core JSON-RPC formatted messages and a few verbs. It doesn't actually do much. The main things are tool definitions which is just a JSON schema describing a function call and resources which a is a wisp of a filesystem.
  - tomashubelbauer 1y ago
    Fair, thought I have a feeling MCP will actually grow to do much more. I wouldn't disagree with the sentiment that it is too bloated too soon, but I also feel like it is destined to be bloated, because the technology it is targeting is sort of a moving target itself. Of course with proper versioning, this is easeable, deprecate stuff that turned out to be the wrong turn and cut major versions or introduce extensions to the protocol when new stuff is on the scene, but then you're liable to find yourself in an XMPP-style situation where no one implements the standard and extensions wholly, because it is so complex.

manojlds 1y ago

Almost no client, including Claude Dekstop, implements Sampling. I was so excited to see if I can create a server that used sampling and quickly figured out I can't use it anywhere. Funnily Windsurf hangs forever if you use sampling.

auggierose 1y ago
Yes, no sampling, last time I tried a few weeks ago. Have you tried with the latest Claude Desktop (0.10.14)?
ericol 1y ago
I've been thinking about this ever since I heard that is defined in the protocol. I think the biggest issue is that it can create loops in the flow of programs that would burn through usage quotas pretty fast. It could also allow for "impersonating" the client what opens up a lot of possibilities. But yeah, the fact that Claude doesn't even implement this is... telling.
- auggierose 1y ago
  Yeah, that is the reason it is not there, I guess, you could then really implement anything just with a flat rate.
disintegrator 1y ago
VS Code seems to be working on it https://www.epicai.pro/using-mcp-sampling-in-vs-code-insiders-dd12d https://www.epicai.pro/using-mcp-sampling-in-vs-code-insider...
esafak 1y ago
For those unfamiliar with the term: "Sampling is a powerful MCP feature that allows servers to request LLM completions through the client, enabling sophisticated agentic behaviors while maintaining security and privacy." https://modelcontextprotocol.io/docs/concepts/sampling https://modelcontextprotocol.io/docs/concepts/sampling

jamesblonde 1y ago

Protocol version in the readme is Full MCP 2025-03-26 specification support in the code it is "protocolVersion": "2024-11-05" https://github.com/hemanth/paws-on-mcp/blob/main/src/mcp_cli_client.py#L46 https://github.com/hemanth/paws-on-mcp/blob/main/src/mcp_cli...

cfors 1y ago
The README is 100% just autogenerated by Claude. It looks like every README generated from these tools. Can’t speak for the code since I haven’t peaked into it
- jamesblonde 1y ago
  I thought it was a bit verbose - lots of repetition. I didn't realize how extensive claude/cursor generated READMEs were.
- owebmaster 1y ago
  The README is a great overview of the MCP features. This is terribly derisive.

jhosft 1y ago

That README.md is so vibed with all the emojis and self-proofed comments. One day we’re going to look back on code written in June 2025 and laugh. The code works, but man does Claude 4 pump itself up.

deleted 1y ago
[deleted]
esafak 1y ago
The median code base it is trained on must be like that.
- hammyhavoc 1y ago
  University student work y'say?
hammyhavoc 1y ago
> The code works Need a phat asterisk after it.

LeonidBugaev 1y ago

It does not implement the Auth :) (mcp auth is terrible btw)

seanobannon 1y ago
I couldn’t find any great examples of MCP auth, so made this demonstrate an oauth flow recently - https://github.com/OBannon37/chatgpt-deep-research-connector-example https://github.com/OBannon37/chatgpt-deep-research-connector...
WXLCKNO 1y ago
For my app I'm bypassing MCP auth and doing the regular oauth2 flow to connect users to external apps. Then I pass the stored oauth token directly to my (private) MCP servers alongside a bearer token.

cranberryturkey 1y ago

also checkout @profullstack/mcp-server on npm

pcwelder 1y ago

Tool annotations are missing. (Are they of any use though?)

welanes 1y ago

This guide may be useful for anyone interested in building their own spec-compliant MCP server: https://simplescraper.io/blog/how-to-mcp https://simplescraper.io/blog/how-to-mcp. Albeit, it's a few weeks old so already in need of an update!

josephg 1y ago

What is MCP? I’ve never heard of it.

esafak 1y ago
Model Context Protocol. The standard for interfacing LLMs with tools. https://modelcontextprotocol.io/ https://modelcontextprotocol.io/
buonu 1y ago
Aka controller or middleware Bit of software between client and backend model to model client requests to It can look like Anthropics model or it can be your own. It’s verbose semantics to describe a little bit of source code. Obfuscation of simple loops and scripts is software industries main product