Spec Driven Development
MCP Server that facilitates spec-driven development workflows, not just Vibe Coding.
Runs on your computer
PennyRail Transaction Router
Overview
Description from the maker (original English)
Find and quote agent capabilities, then pay only the selected x402 execution URL.
PopNx MCP’s three pillars
These three are never merged into one score: opinions, measurements and popularity are different things.
- User voiceiNo reviews yetReviews open together with accounts in a later step
- Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
- UsageiVery new★ –
What you can do with it
We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.
- Connection: Runs in the cloud
- Transport: Streamable HTTP
- Category: Other
Install
Pick the AI app you use, then copy the settings.
Before you install
- Basic checks: 1 of 1 passed
- Runs on the maker’s server: what you ask it goes through their server.
- The registry lists no key to fill in.
You need
- Runs in the cloudNothing to install; it connects over the internet
Which app do you use?
Pick your app above. We remember it, so next time the button says “Install in …”.
Works in Claude on the web, desktop and mobile:
- Open Settings → Connectors
- Press Add custom connector
- Paste the address below and press Add
- If it asks you to sign in, sign in with the maker
https://pennyrail.vercel.app/api/mcpRun this in your terminal
claude mcp add --transport http pennyrail https://pennyrail.vercel.app/api/mcpOr copy the settings yourself
Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json
{
"mcpServers": {
"pennyrail": {
"url": "https://pennyrail.vercel.app/api/mcp"
}
}
}Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.
Or copy the settings yourself
Paste into .vscode/mcp.json in your project
{
"servers": {
"pennyrail": {
"type": "http",
"url": "https://pennyrail.vercel.app/api/mcp"
}
}
}Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.
ChatGPT connects only to servers on the internet:
- Open ChatGPT on the web → Settings → Connectors (Apps)
- Press Create or Add (some plans need Developer mode under Advanced first)
- Paste the address below, give it a name and save
- If it asks you to sign in, sign in with the maker
https://pennyrail.vercel.app/api/mcpMenu names can differ slightly by plan and over time.
Your choice stays on this device in a cookie; no account needed.
These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.
What it can do
We have not read this server’s tool list yet; we check endpoints in rotation.
Basic checksi
We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 9, 2026
- ✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account clay-swartz, which owns the repo
- … Not checked yet
Still maintained
We have not read this repo from GitHub yet
- … Not checked yet
Has a licence
We have not read this repo from GitHub yet
- … Not checked yet
Endpoint responds
Not checked yet; we check endpoints in rotation
- … Not checked yet
Sign-in with OAuth
Not checked yet; we check endpoints in rotation
- … Not checked yet
No hidden instructions in tool descriptions
Not checked yet; we read the tool list when we check the endpoint
Compared with others in Otheri
- More stars than 0% of the other 18871 servers in this category
- Published to the registry more recently than 30% of the other 18871 servers in this category
- Basic checks equal to or better than 100% of the other 18871 servers in this category
Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.
Common questions
Is PennyRail Transaction Router safe?
It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.
What keys or codes does it need?
The registry does not list a required key, though some servers ask you to sign in on first use.
Does it run on my computer or in the cloud?
It runs in the maker’s cloud. Connect over the internet with nothing to install, but what you send passes through the maker’s servers.
Is it still maintained?
The GitHub repo last changed –, and the latest version (0.9.0) reached the registry 2 months ago.
Which apps can use it?
Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. It connects by URL, so apps that accept remote MCP servers work too, such as ChatGPT in developer mode.
What can I use instead?
In the same category: Spec Driven Development, Remote Desktop Commander, NotebookLM MCP
Alternatives
Servers in the same category from other makers, sorted by stars.
Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi
Remote Desktop Commander
Remote Desktop Commander: use files, terminal and processes on your own computers from any AI app.
Runs in the cloud✓ desktopcommander.app
NotebookLM MCP
Google Gemini Notebook (ex NotebookLM) over MCP + a local REST API — cited answers, Studio, history
Runs on your computer
README from the maker
Open the README
Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.
PennyRail
PennyRail is an autonomous machine-commerce yield engine: observe paid agent demand, identify monetizable capability gaps, publish the smallest reliable solution, charge per machine call, distribute it across agent-buying surfaces, and keep expanding the portfolio around proven demand.
Current build — v36 Revenue Broker
Current revenue loop:
PAID DEMAND → MAP/GAP → BUILD REUSABLE PRIMITIVE → PRICE → PUBLISH → SELL/BID → MEASURE → MULTIPLY
The production stack includes:
- Base USDC x402 settlement with the proven Coinbase facilitator integration
- 47 original factory capabilities plus proven-demand templates
- dynamic revenue-product routes and machine-readable OpenAPI/x402 discovery
- paid Agent402 Bestsellers intelligence every six hours (Demand Radar disabled while its upstream itemized feed is empty)
- x402scan registration and x402 List review submission
- the402 provider/catalog/request-bidding integration
- optional OpenAI upstream broker capabilities, including live web search
- private Radar dashboard with on-chain outside-revenue tracking, remembered admin access and one-click JSON copying
See README_REVENUE_BROKER_V36.md for the current revenue build. Historical version notes are intentionally preserved in the versioned README files.
Production secrets
Secrets belong in Vercel Production environment variables only. Never commit admin tokens, wallet credentials, provider API keys, webhook secrets or OpenAI keys to the repository.
Operating objective
Maximize aggregate machine-commerce gross profit across many tiny transactions. Current internal target: at least $1,000/day / $30,000/month, with no architecture ceiling. This is a target, not a guarantee.