AISchemaGate and DataContractGate

Name: AISchemaGate and DataContractGate
Author: nightmoose

by nightmooseversion 0.4.1i★ 4 (Stars for the whole repo)iRuns on your computer

Registry nameio.github.nightmoose/contractgate

How to install

What it does

AISchemaGate validates and repairs structured LLM output against a contract, plus DataContractGate.

Connects Runs on your computer
Account or key Needs CONTRACTGATE_API_KEY
Category Search & AI memory

Install

Pick the AI app you use, then copy the settings.

Passed 3/3 checks · Runs on your computer · ✓ Commands checked Nov 14, 2026

First: which AI do you use?

ClaudeWeb · app · phoneChatGPTWebClaude CodeTerminalCursorCode editorVS CodeCode editorOtherOther apps

Pick your app and the steps appear below.

Works with Claude, with some setup first

You need a AISchemaGate and DataContractGate key (create it on the maker’s site) · Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone

Let AI install it

Copy this message into a Claude chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server AISchemaGate and DataContractGate for Claude on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "mcpServers": { "contractgate": { "command": "npx", "args": [ "-y", "@nightmoose/contractgate-mcp-server" ], "env": { "CONTRACTGATE_API_KEY": "your-value" } } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) For CONTRACTGATE_API_KEY, leave "your-value" in place and tell me to paste the real value myself into the file or the app’s field. Never ask me to type a key in chat. 5) Do what we agreed, then check that the AISchemaGate and DataContractGate tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Sign up and create a AISchemaGate and DataContractGate key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the AISchemaGate and DataContractGate site ↗
Done
Open the Claude desktop app’s settings file
SettingsDeveloperEdit Config
Done

Paste these settings and save the file

{
  "mcpServers": {
    "contractgate": {
      "command": "npx",
      "args": [
        "-y",
        "@nightmoose/contractgate-mcp-server"
      ],
      "env": {
        "CONTRACTGATE_API_KEY": "your-value"
      }
    }
  }
}

Paste the key only into the app’s field, never into a chat or to anyone

Done

Quit Claude and open it again
Done
Try it
Use AISchemaGate and DataContractGate and tell me what you can do for me, then show me one thing
✓ If Claude says it is using AISchemaGate and DataContractGate or shows a AISchemaGate and DataContractGate tool in the answer, you are connected

1 optional setting(s) (works without them)

The command above works without these. Add them only if you want to change something, following the maker’s description.

CONTRACTGATE_BASE_URL Gateway base URL. Defaults to https://api.datacontractgate.com

Descriptions are as written by the maker.

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

ChatGPT cannot connect AISchemaGate and DataContractGate yet

AISchemaGate and DataContractGate runs on your computer, but ChatGPT can only connect servers that run on the web

What you can do instead

A · Use an app that can connect AISchemaGate and DataContractGate

Steps for Claude →You need a AISchemaGate and DataContractGate key (create it on the maker’s site) · Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone
Steps for Claude Code →You need a AISchemaGate and DataContractGate key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Steps for Cursor →You need a AISchemaGate and DataContractGate key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Steps for VS Code →You need a AISchemaGate and DataContractGate key (create it on the maker’s site) · Install Node.js on your computer first (one time)

B · Others in Search & AI memory that work with ChatGPT

Picked from the most used in the same category, only ones that connect by address with no key

Context7✓ ChatGPT
OpenSEO✓ ChatGPT
AIHOT✓ ChatGPT

Works with Claude Code, with some setup first

You need a AISchemaGate and DataContractGate key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a Claude Code chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server AISchemaGate and DataContractGate for Claude Code on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): claude mcp add --scope user contractgate --env CONTRACTGATE_API_KEY=your-value -- npx -y @nightmoose/contractgate-mcp-server 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) For CONTRACTGATE_API_KEY, leave "your-value" in place and tell me to paste the real value myself into the file or the app’s field. Never ask me to type a key in chat. 5) Do what we agreed, then check that the AISchemaGate and DataContractGate tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Sign up and create a AISchemaGate and DataContractGate key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the AISchemaGate and DataContractGate site ↗
Done
Open Terminal
Mac: press Command+Space and type Terminal · Windows: open PowerShell
Done
4
Paste this command and press Enter
```
claude mcp add --scope user contractgate --env CONTRACTGATE_API_KEY=your-value -- npx -y @nightmoose/contractgate-mcp-server
```
Replace “your-value” with your key before pressing Enter
Paste the key only into the app’s field, never into a chat or to anyone
Done
Type /mcp in Claude Code
You should see AISchemaGate and DataContractGate listed as connected
Done
Try it
Use AISchemaGate and DataContractGate and tell me what you can do for me, then show me one thing
✓ If Claude Code says it is using AISchemaGate and DataContractGate or shows a AISchemaGate and DataContractGate tool in the answer, you are connected

1 optional setting(s) (works without them)

The command above works without these. Add them only if you want to change something, following the maker’s description.

CONTRACTGATE_BASE_URL Gateway base URL. Defaults to https://api.datacontractgate.com

Descriptions are as written by the maker.

Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with Cursor, with some setup first

You need a AISchemaGate and DataContractGate key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a Cursor chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server AISchemaGate and DataContractGate for Cursor on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "mcpServers": { "contractgate": { "command": "npx", "args": [ "-y", "@nightmoose/contractgate-mcp-server" ], "env": { "CONTRACTGATE_API_KEY": "your-value" } } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) For CONTRACTGATE_API_KEY, leave "your-value" in place and tell me to paste the real value myself into the file or the app’s field. Never ask me to type a key in chat. 5) Do what we agreed, then check that the AISchemaGate and DataContractGate tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Sign up and create a AISchemaGate and DataContractGate key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the AISchemaGate and DataContractGate site ↗
Done
Click this button to open Cursor
Open in Cursor
Cursor asks you to confirm; click Install
Done
Fill in your key
In the AISchemaGate and DataContractGate settings, CONTRACTGATE_API_KEY is empty; add your key and save
Paste the key only into the app’s field, never into a chat or to anyone
Done
Open the AI chat in Cursor in Agent mode
Done
Try it
Use AISchemaGate and DataContractGate and tell me what you can do for me, then show me one thing
✓ If Cursor says it is using AISchemaGate and DataContractGate or shows a AISchemaGate and DataContractGate tool in the answer, you are connected

1 optional setting(s) (works without them)

The command above works without these. Add them only if you want to change something, following the maker’s description.

CONTRACTGATE_BASE_URL Gateway base URL. Defaults to https://api.datacontractgate.com

Descriptions are as written by the maker.

Menu names checked against Cursor’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Works with VS Code, with some setup first

You need a AISchemaGate and DataContractGate key (create it on the maker’s site) · Install Node.js on your computer first (one time)

Let AI install it

Copy this message into a VS Code chat. The AI checks your computer, tells you which file it will change, and waits for your OK every time.

Please install the MCP server AISchemaGate and DataContractGate for VS Code on this computer, in this order: 1) Check Node.js with node -v. If it is missing, tell me to install it from https://nodejs.org/en/download; do not install it yourself. 2) Use only this config (already checked by PopNx MCP): { "servers": { "contractgate": { "type": "stdio", "command": "npx", "args": [ "-y", "@nightmoose/contractgate-mcp-server" ], "env": { "CONTRACTGATE_API_KEY": "your-value" } } } } 3) Tell me the full path of the file you will change, or the command you will run, and wait for my OK. 4) For CONTRACTGATE_API_KEY, leave "your-value" in place and tell me to paste the real value myself into the file or the app’s field. Never ask me to type a key in chat. 5) Do what we agreed, then check that the AISchemaGate and DataContractGate tools really show up.

This message has no key in it. If a key is needed, the AI will ask you to paste it yourself into the file or the app’s field.

1
Install Node.js (if you don’t have it)
Already installed? Check first · Open Terminal, type this command and press Enter
node -v
- A version number such as v26.13.1 = installed, skip this step
- "command not found" (on Windows: "is not recognized") = not installed yet, or installed but Terminal needs to be closed and reopened
How to open Terminal
Mac: press ⌘ + Space, type Terminal, press Enter
Windows: open Start, type Windows PowerShell, then Open
Not installed: Open the official download page, pick the LTS version and the click-through installer: .pkg on Mac · .msi on Windows. Double-click and follow it to the end. No curl command needed
Open the Node.js download page ↗
When it’s done, close Terminal, open it again and run the same command. You should see a version number: node -v
Install once; it works for everything that needs Node.js
Done
Sign up and create a AISchemaGate and DataContractGate key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the AISchemaGate and DataContractGate site ↗
Done
Click this button to open VS Code
Open in VS Code
VS Code asks you to confirm; click Install
Done
Fill in your key
In the AISchemaGate and DataContractGate settings, CONTRACTGATE_API_KEY is empty; add your key and save
Paste the key only into the app’s field, never into a chat or to anyone
Done
Open the AI chat in VS Code in Agent mode
Done
Try it
Use AISchemaGate and DataContractGate and tell me what you can do for me, then show me one thing
✓ If VS Code says it is using AISchemaGate and DataContractGate or shows a AISchemaGate and DataContractGate tool in the answer, you are connected

1 optional setting(s) (works without them)

The command above works without these. Add them only if you want to change something, following the maker’s description.

CONTRACTGATE_BASE_URL Gateway base URL. Defaults to https://api.datacontractgate.com

Descriptions are as written by the maker.

Menu names checked against VS Code’s help page on Nov 11, 2026 · your screen may differ slightly by app version

Other apps that use MCP, such as Windsurf, Zed or Gemini CLI, each add servers differently. See how in the app list.

See every app that uses MCP →

JSON settings are under “For developers” below

Stuck? Ask people who use AISchemaGate and DataContractGate💬 Discussion →

For developers: Terminal commands and JSON settings

Installed on your computer

Claude Code

claude mcp add --scope user contractgate --env CONTRACTGATE_API_KEY=your-value -- npx -y @nightmoose/contractgate-mcp-server

Claude Desktop (claude_desktop_config.json)

{
  "mcpServers": {
    "contractgate": {
      "command": "npx",
      "args": [
        "-y",
        "@nightmoose/contractgate-mcp-server"
      ],
      "env": {
        "CONTRACTGATE_API_KEY": "your-value"
      }
    }
  }
}

Cursor (~/.cursor/mcp.json)

{
  "mcpServers": {
    "contractgate": {
      "command": "npx",
      "args": [
        "-y",
        "@nightmoose/contractgate-mcp-server"
      ],
      "env": {
        "CONTRACTGATE_API_KEY": "your-value"
      }
    }
  }
}

VS Code (mcp.json)

{
  "servers": {
    "contractgate": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@nightmoose/contractgate-mcp-server"
      ],
      "env": {
        "CONTRACTGATE_API_KEY": "your-value"
      }
    }
  }
}

Values you fill in

CONTRACTGATE_API_KEY secret required env
DataContractGate API key (cg_live_...). Create one at https://app.datacontractgate.com/account
CONTRACTGATE_BASE_URL env
Gateway base URL. Defaults to https://api.datacontractgate.com

Descriptions are as written by the maker.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

At a glance

GitHub stars i: 4 (Stars for the whole repo)
This repo holds several MCP listings; its stars count once in rankings
Downloads per weeki: 123/wk
Licence i: MIT
Connection: Runs on your computer
Transport: stdio
Latest versioni: 0.4.1
Categoryi: Search & AI memory
Published to registryi: Oct 29, 2026
Code last changedi: Nov 14, 2026
Maker: nightmoose
Packages: npm: @nightmoose/contractgate-mcp-server
Repo: nightmoose/contractgate
Website: app.datacontractgate.com
Registry status: Active

Which apps can use it

Based on how this server connects and on each app’s own docs, checked Nov 10, 2026.

Run on your computer in

Claude Goose LM Studio Msty Studio Cherry Studio Cursor VS Code + GitHub Copilot Visual Studio Windsurf (Devin Desktop)Zed Kiro Cline Continue JetBrains AI Assistant Claude Code Codex CLI Gemini CLI OpenCode nodecode Warp LibreChat Raycast

All apps, with pros and cons →

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

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 15, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account nightmoose, which owns the repo
✓ Pass
Still maintained
Code last changed yesterday
✓ Pass
Has a licence
Uses MIT
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Published vulnerabilities (OSV.dev)

Not checked yet

What we check → · JSON

Makers: ask for a re-check or report wrong info

Discussion

Ask, share a tip or report that it does not work. Sorted by what people marked helpful.

No posts yet. Be the first to ask or share.

Posts here are written by users, not the PopNx team.

User reviews

No reviews yet

Compared with others in Search & AI memoryi

More stars than 76% of the other 6154 servers in this category
Published to the registry more recently than 69% of the other 6154 servers in this category
Basic checks equal to or better than 100% of the other 6154 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 AISchemaGate and DataContractGate safe?

It passed 3 of 3 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?

You need to fill in: CONTRACTGATE_API_KEY

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed yesterday, and the latest version (0.4.1) reached the registry 17 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: OpenSEO, Exa, Mockserver, Microsoft Learn MCP, Docs

Similar alternatives

Same category, other makers, commands already checked. Official ones first, then by stars.

Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

OpenSEO

Keyword research, site audits, rank tracking and AI visibility for your AI agent.

by every-appWidely used★ 27.7KUpdated yesterday

Runs in the cloud✓ everyapp.com

How to connect

Exa

Connect AI agents to Exa for web search, content fetching, and multi-step research.

by exa-labsWidely used★ 5.2KUpdated 2 months ago

Runs in the cloud✓ service owner · exa.aiTried by the PopNx team

How to connect

Mockserver

Mock, record/replay, verify and chaos-test any HTTP, REST, gRPC or LLM dependency over MCP.

by mock-serverGrowing★ 5KUpdated 19 days ago

Runs on your computer✓ service owner · mock-server.com

Install

Microsoft Learn MCP

Official Microsoft Learn MCP Server – real-time, trusted docs & code samples for AI and LLMs.

by MicrosoftDocsWidely used★ 2KUpdated 12 months ago

Runs in the cloud✓ service owner · microsoft.comTried by the PopNx team

How to connect

Docs

Search and read Empryo's documentation. Read-only, no auth, no local access.

by proxysoulGrowing★ 1.6KUpdated 2 months ago

Runs in the cloud✓ empryo.com

How to connect

OpenSEO — Runs in the cloud, nothing to install · No key needed
Exa — Runs in the cloud, nothing to install · No key needed · In Claude’s directory
Mockserver — Installs on your computer · No key needed
Microsoft Learn MCP — Runs in the cloud, nothing to install · No key needed · In Claude’s directory
Docs — Runs in the cloud, nothing to install · No key needed

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.

@nightmoose/contractgate-mcp-server

AISchemaGate validates and repairs structured LLM output against a contract, plus DataContractGate data contracts. Repair uses the violation fields from that check. The contract checks values a JSON Schema or Pydantic validation can leave open.

Official Model Context Protocol server. Thin stdio wrapper over the HTTP API at https://api.datacontractgate.com (override with CONTRACTGATE_BASE_URL). The dashboard host https://app.datacontractgate.com is not the gateway.

One server, two products, same API key:

AISchemaGate — validates structured LLM output (egress_validate → POST /egress/{id}). Repair uses the violation fields from that check (min, max, pattern, enum, compliance_mode). Forward payload from the tool result, not the original body.
DataContractGate — infer and deploy data contracts, validate ingest (validate_events → POST /v1/ingest/{id}), including ODCS v3.1.0 and v3.2.0 contracts, and inspect quarantine (get_quarantine). Replay stays on the HTTP API (POST /contracts/{id}/quarantine/replay).

Registry metadata for the Official MCP Registry is server.json. The title and description lead with AISchemaGate (description is the 100-character registry field). The server name stays io.github.nightmoose/contractgate. Keywords and the longer summary are under _meta. Smithery config is smithery.yaml; its default contractgateBaseUrl is the API gateway. npm keywords, this README, and DIRECTORY_LISTINGS.md are the directory listing.

See docs/mcp-reference.md for tools and auth. AISchemaGate app integrations: docs/integrations/.

"mcpServers": { "contractgate": { "command": "npx", "args": ["-y", "@nightmoose/contractgate-mcp-server"], "env": { "CONTRACTGATE_API_KEY": "${CONTRACTGATE_API_KEY}" } } } }

cd mcp

npm install npm test npm run build

AISchemaGate and DataContractGate

What it does

Install

Install Node.js (if you don’t have it)

Sign up and create a AISchemaGate and DataContractGate key

Open the Claude desktop app’s settings file

Paste these settings and save the file

Quit Claude and open it again

Try it

What you can do instead

Install Node.js (if you don’t have it)

Sign up and create a AISchemaGate and DataContractGate key

Open Terminal

Paste this command and press Enter

Type /mcp in Claude Code

Try it

Install Node.js (if you don’t have it)

Sign up and create a AISchemaGate and DataContractGate key

Click this button to open Cursor

Fill in your key

Open the AI chat in Cursor in Agent mode

Try it

Install Node.js (if you don’t have it)

Sign up and create a AISchemaGate and DataContractGate key

Click this button to open VS Code

Fill in your key

Open the AI chat in VS Code in Agent mode

Try it

Installed on your computer

Values you fill in

At a glance

Which apps can use it

Related guides

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Published vulnerabilities (OSV.dev)

Discussion

User reviews

Compared with others in Search & AI memoryi

Common questions

Similar alternatives

OpenSEO

Exa

Mockserver

Microsoft Learn MCP

Docs

README from the maker

@nightmoose/contractgate-mcp-server