Here are the main themes from the Hacker News discussion, along with supporting quotes:
Initial Access and Usability Issues
Many users reported immediate difficulties accessing the new feature, citing errors, browser compatibility issues, and CAPTCHA loops. This suggests a rocky rollout and poor initial user experience.
ranger_danger: "First the page gave me an error message. I refreshed and then it said my browser was 'out of date' (read: fingerprint resistance is turned on). Turned that off and now I just get an endless captcha loop. I give up."knowaveragejoe: "Same."
Excitement and Potential for Advanced AI Agents
Despite the initial access issues, there's significant enthusiasm for ChatGPT's integration of MCPs, with many seeing it as a crucial step towards more powerful and autonomous AI agents. Users are envisioning complex workflows and broader applications for this capability.
dormento: "When you think about it, isn't it kind of a developer's experience?"CuriouslyC: "I've been waiting for ChatGPT to get MCPs, this is pretty sweet. Next step is a local system control plane MCP to give it sandbox access/permission requests so I can use it as an agent from the web."ObnoxiousProxy: "I'm actually working on an MCP control plane and looking for anyone who might have a use case for this / would be down to chat about it. We're gonna release it open source once we polish it in the next few weeks."CuriouslyC: "A MCP gateway is a useful tool, I have a prototype of something similar I built but I'm not super enthusiastic about working on it (bigger fish to fry). One thing I'd suggest is to have a meta-mcp that an agenct can query to search for the best tool for a given job, that it can then inject into its context."A4ET8a8uTh0_v2: "Interesting, for once 'Matrix's 'programs hacking programs' vision kinda starts to make some sense."moritonal: "Pretty neat honestly."CuriouslyC: "Basically, my philosophy with agents is that I want to orchestrate agents to do stuff on my computer rather than use a UI."yalogin: "Interestingly all the LLMs and the surrounding industry is doing is automate software engineering tasks."- `ripped_">>It's powerful but dangerous, and is intended for developers who understand how to safely configure and test connectors."
bdesimone: "Full MCP support was the only thing holding me back from using GPT5 as my daily driver as it has been my "go to" for hard problems and development since it was released."zoba: "This is OpenAI dipping their toe in the water of the integrations part of the future Sam and Jony are imagining."
Practical Use Cases and Examples
Users shared concrete examples of how they are using or envisioning the use of MCPs, demonstrating the practical application of the technology across various domains.
boredtofears: "At my work were replacing administrative interfaces/workflows with an MCP to hit specific endpoints of our REST API."theshrike79: "Playwright mcp lets the agent operate a browser to test the changes it made, it can click links, execute JavaScript and analyse the dom."baby_souffle: "I was looking at Ghidra MCP but - apparently - plugins to Ghidra must be compiled for that version of ghidra and I was not in the mood to set up a ghidra dev environment... but I was able to get fantastic results just pasting some pseudo code into GPT and asking 'what does this do given that iVar1 is ...' and I got back a summary that was correct."moritonal: "'Please find 3 fencing clubs in South London, find out which offer training sessions tomorrow, then add those sessions to my Calendar.' That kicked off a maps MCP, a web-research MCP and my calendar MCP."CuriouslyC: "I have an agent that analyzes my google analytics in depth and provides feedback on performance with actionable next steps that it can then complete (A/B tests, etc)."stingraycharles: "I use zen-mcp-server for workflow automation."mickael-kerjean: "It lets you connect to any kind of storage protocol that possible exist from S3, SFTP, FTS, SMB, NFS, Sharepoint, .... and layers its own fine grained permission control / chroots that integrate through SSO / RBAC."nullbyte: "Dominos Pizza MCP would be sick"lbeckman314: "TIL Domino's has an (unofficial/experimental) MCP Server + API"
Security Concerns and Prompt Injection Risks
A significant portion of the discussion revolves around the inherent security risks, particularly prompt injection, associated with empowering AI models with external tool access. Many users expressed concern about the potential for misuse and the lack of robust safeguards.
simonw: "Wow this is dangerous. I wonder how many people are going to turn this on without understanding the full scope of the risks it opens them up to. It comes with plenty of warnings, but we all know how much attention people pay to those."simonw: "I'm confident that the majority of people messing around with things like MCP still don't fully understand how prompt injection attacks work and why they are such a significant threat."darkamaul: "I’m not sure I fully understand what the specific risks are with this system, compared to the more generic concerns around MCP. Could you clarify what new threats it introduces?"Yeroc: "Imagine running an MCP server inside your network that grants you access to some internal databases. You might expect this to be safe but once you connect that internal MCP server to an AI agent all bets are off."withinboredom: "They weren’t kidding about hooking mcp servers to internal databases. You see people all the time connecting LLMs to production servers and losing everything — on reddit. Its honestly a bit terrifying."jonplackett: "The problem is known as the lethal trifecta. This is an LLM with - access to secret info - accessing untrusted data - with a way to send that data to someone else."simonw: "The lack of a 100% guarantee is entirely the problem. If you get to 99% that's still a security hole, because an adversarial attacker's entire job is to keep on working at it until they find the 1% attack that slips through."cedws: "IMO the way we need to be thinking about prompt injection is that any tool can call any other tool. When introducing a tool with untrusted output (that is to say, pretty much everything, given untrusted input) you’re exposing every other tool as an attack vector."NumPy-thagoras: "I have prompt-injected myself before by having a model accidentally read a stored library of prompts and get totally confused by it."NomDePlum: "How any mature company can allow this to be enabled for their employees to use is beyond me."
Technical Challenges and Implementation Details
Users discussed the nitty-gritty of MCP implementation, including issues with streaming protocols, OAuth configurations, and the general complexity of integrating these systems.
ayhanfuat: "What is the error you are getting? I get 'Error fetching OAuth configuration' with an MCP server that I can connect to via Claude."tosh: "'error creating connector' our MCP also works fine with Claude, Claude Code, Amp, lm studio and other but not all MCP clients MCP spec and client implementations are a bit tricky when you're not using FastMCP (which we are not)."dougbarrett: "I wonder if it's a difference between SSE and HTTP streaming support?"mickael-kerjean: "mine does support SSE (https://github.com/mickael-kerjean/filestash) but it fails before getting there..."quinncom: "I get this error trying to connect the Mapbox hosted MCP server: 'Something went wrong with setting up the connection'"lyu07282: "Lots of people reported issues in the forums weeks ago, seems like they haven't improved it much (what's the point of doing a beta if you ignore everyone reporting bugs?)"danjc: "I think you've nailed it there. OpenAI are at a point where the risk of continuing to hedge on mcp outweighs the risk of mcp calls doing damage."srcreigh: "Use codex CLI"ionwake: "this is an AI JSON format that anthropic invented, that the big companies have adopted"
Agent Architecture and Workflow Orchestration
There's a clear interest in more sophisticated agent architectures, with discussions on inversion of control, meta-MCPs for tool selection, and orchestrating multiple agents for complex tasks.
CuriouslyC: "My agent (Smith) has an inversion of control architecture where rather than running as a process on a system and directly calling tools on that system, it emits intents to a queue, and an executor service that watches that queue and analyzes those intents, validates them, schedules them and emits results back to an async queue the agent is watching."ObnoxiousProxy: "Our gateway lets team members bundle together configured MCPs into a unified MCP server with only two tools -- search and execute, basically a meta-mcp!"CuriouslyC: "Orchestrating current agent tools is clunky, they're low performance, they lack fine grained extensibility to really modify their behavior on a dynamic task based basis..."qarl: "There's no need to belittle dataflow graphs. They are quite a nice model in many settings. I daresay they might be the PERFECT model for networks of agents."lelandbatey: "The killer app of comfy UI and node based editors in general is that they allow 'normal people' to do programmer-like things, almost like script like things. In a word: you have better repeatability and appropriate flexibility/control."mnky9800n: "I feel like at least for data analysis it would be interesting to have the ability to build a data dashboard on the fly."
The "Developer Mode" Label and Target Audience
Users debated the naming of the feature as "Developer Mode," with some finding it an accurate descriptor of its power and danger, while others noted that even self-identified developers might not fully grasp the implications.
moralestapia: "> It's powerful but dangerous, and is intended for developers who understand how to safely configure and test connectors. Right in the opening paragraph. Some people can never be happy."islewis: "So... practically no one? My experience has been that almost everyone testing these cutting edge AI tools as they come out are more interested in new tool shinyness than safety or security."meow_mix: "I'm confused and I'm a developer."romanovcode: "Same. What exactly is 'developer' about: 'Schedule a 30‑minute meeting tomorrow at 3pm PT with alice@example.com and bob@example.com using "Calendar.create_event".'"giveita: "Only footgun operators may apply is what they mean."jumploops: "Calling it 'Developer Mode' is likely just to prevent non-technical users from doing dangerous things, given MCP's lack of security and the ease of prompt injection attacks."