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SingIt x402

by SingItAiversion 0.1.4i★ –iRuns in the cloud
Registry nameapp.singitai/singit

Install

Overview

Description from the maker (original English)

Web search, page reading, prices and market data for agents, billed to your SingIt API key in USDC.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

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: Search & AI memory
  • You need to fill in: Authorization

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.
  • You fill in yourself: Authorization

Values marked secret are keys to your account. Never share them or paste them into a chat.

You need

Which app do you use?

Pick your app above. We remember it, so next time the button says “Install in …”.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Run this in your terminal

claude mcp add --transport http singit https://app.singitai.app/mcp --header 'Authorization: your-value'

Fill in the empty values before running it.

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "singit": {
      "url": "https://app.singitai.app/mcp",
      "headers": {
        "Authorization": "your-value"
      }
    }
  }
}

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.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "singit": {
      "type": "http",
      "url": "https://app.singitai.app/mcp",
      "headers": {
        "Authorization": "your-value"
      }
    }
  }
}

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.

This address needs a key in a request header, which the add-connector menu cannot set. Use Claude Code, Cursor or VS Code instead.

Your choice stays on this device in a cookie; no account needed.

Values you fill in

  • Authorization secret HTTP header
    Bearer followed by your SingIt API key, from https://app.singitai.app/app/. Needed only for paid tools.

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 6, 2026

  • ✓ Pass

    Maker matches the repo

    The registry name was verified against the domain singitai.app (the registry checks domain ownership)

  • … 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 Search & AI memoryi

  • More stars than 0% of the other 7241 servers in this category
  • Published to the registry more recently than 85% of the other 7241 servers in this category
  • Basic checks equal to or better than 100% of the other 7241 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 SingIt x402 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?

You need to fill in: Authorization

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 (0.1.4) reached the registry 6 days 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: Context7, Codebase Memory, Exa

Alternatives

Servers in the same category from other makers, sorted by stars.

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

Context7

by upstash

Feeds AI the latest docs for libraries and frameworks before it answers, so code it writes does not use outdated, removed functions.

Computer or cloud★ 64,224MITUpdated 3 days ago
Install

Codebase Memory

by DeusData

Codebase knowledge graph for AI agents — 162 languages, sub-ms queries, 99% fewer tokens.

Runs on your computer★ 48,148MITUpdated 20 days ago
Install

Exa

by exa-labs

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

Runs in the cloud★ 5,213MITUpdated 44 days ago
Install

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.

SingIt MCP

Give an agent SingIt tools with an MCP key with limits your owner sets: a daily limit, a per-request limit and an expiry, signed by the owner's wallet.

Docs · Tools reference · Developers · Main repository

SingIt runs a remote MCP server. There is nothing to install and no local process: your client connects to one URL.

https://app.singitai.app/mcp

Streamable HTTP, JSON responses only (no SSE, no sessions). MCP Registry name: app.singitai/singit. Server singit "SingIt x402", version 0.1.5 once deployed (the live server reports 0.1.3 until then); protocol 2025-06-18.

Claude Code in 60 seconds

Configuration examples, not run live. The chat tools require the gateway deployment of 0.1.5.

  1. Add the server without a key:
   claude mcp add --transport http --scope user singit https://app.singitai.app/mcp

claude mcp list

The list should show singit: https://app.singitai.app/mcp (HTTP) - ✔ Connected.

  1. Ask: "Use the SingIt chat_free tool to explain x402 in two sentences."

Free, no key, short answers (up to 400 tokens), using free/deepseek-v4.1-flash by default. The result includes billing.remainingToday and billing.resetsAt. A small daily allowance is counted per network, and a shared daily budget can run out. The result also hints to drop the free/ prefix to pay with chat.

  1. For paid answers, create an MCP key with limits, then export it before starting Claude Code and replace the keyless configuration:
   export SINGIT_API_KEY=sk_singit_...

claude mcp remove singit --scope user claude mcp add --transport http --scope user singit https://app.singitai.app/mcp --header 'Authorization: Bearer ${SINGIT_API_KEY}'

Ask: "Use the SingIt chat tool to explain x402 in detail." Then use get_limits to check the remaining budget and get_receipts to check the charge.

See the Claude Code guide.

Plugins for Claude Code and Codex

Claude Code (adds the MCP server plus /singit:limits, /singit:receipts and a "price before a paid call" skill):

/plugin marketplace add SingItAi/singit-mcp

/plugin install singit@singit

Codex (adds the MCP server with your key, plus the singit-limits, singit-receipts and price-before-paid-call skills). It needs an MCP key with limits in SINGIT_API_KEY before Codex starts: Codex does not start the server when the variable is unset (we checked), so for the free tools without a key use codex mcp add singit --url https://app.singitai.app/mcp instead.

export SINGIT_API_KEY=...   # your MCP key

codex plugin marketplace add SingItAi/singit-mcp codex plugin add singit@singit

The Claude Code plugin works without a key (free tools, chat_free; it only warns about the unset variable). For paid tools and your limits, create an MCP key with limits and export SINGIT_API_KEY in the environment that starts the client; the plugins read it from there and never store it. /singit:limits and /singit:receipts call the free, read-only get_limits and get_receipts. The limits they show are the ones SingIt's server checks for calls made with that key to SingIt's MCP and /v1; they do not limit anything an agent spends elsewhere. The plugin files live in plugins/claude and plugins/codex; the marketplace manifests are .claude-plugin/marketplace.json and .agents/plugins/marketplace.json.

MCP key with limits

Suggested terms: $1 a day, $0.05 a request, 7 days. In the SingIt app, the “Agent via MCP” preset fills these in. The server's own defaults when you do not change anything are $5 a day, $0.25 a request, 90 days. The minimum daily cap is $0.01 and the maximum is $1000.

  1. Open the SingIt app and set up a SingIt allowance from your wallet: a Base limiter or Solana delegation. Paid MCP search and data tools need it. Without it, the tool says “Set up your allowance first.”
  2. Open Settings → API keys. Your wallet signs the name, daily limit, per-request limit and duration. The key is shown once.
  3. Export SINGIT_API_KEY securely in the environment that launches your client. Never put the key in chat, logs or a file.

Quick start

Configuration examples, not run live.

The free tools and tools/list work without a key, so you can add the server and look around first.

Claude Code

claude mcp add --transport http singit https://app.singitai.app/mcp --header 'Authorization: Bearer ${SINGIT_API_KEY}'

Single quotes keep ${SINGIT_API_KEY} as a reference so the key is not written into Claude Code's configuration.

Codex

codex mcp add singit --url https://app.singitai.app/mcp --bearer-token-env-var SINGIT_API_KEY

Cursor and other clients with a `url` and `headers` JSON config (see .mcp.json; Windsurf uses serverUrl, see docs/clients.md):

{

"mcpServers": { "singit": { "url": "https://app.singitai.app/mcp", "headers": { "Authorization": "Bearer ${env:SINGIT_API_KEY}" } } } }

More clients and per-client notes: docs/clients.md.

What the limits do and do not do

The key's daily and per-request caps are enforced by SingIt's server for calls made with that key to SingIt's MCP and the same key's /v1 endpoint. They do not limit what an agent spends anywhere else. SingIt's contracts do not protect other people's agents' own wallets.

On Base the owner's allowance limiter is an on-chain contract the owner can pause. On Solana key caps are checked by SingIt's server; the owner can revoke the delegation. There is no on-chain emergency stop. A paused Solana account is unpaused only by a new grant signed after the pause.

For a $0.01 daily cap, the refusal from web_api_keys.py is:

This key's daily limit of 0.01 USDC is used up, counting requests still running. It starts again at 00:00 UTC, or raise it with a new key.

This quote comes from the code, not run live. The server counts today's spend, held amounts for running calls and the most the next call may cost before allowing it. A refused call returns isError true; nothing is bought or charged for it. Stop when a limit refuses; do not try to bypass it.

Revoke immediately in Settings → API keys; no wallet signature is needed. A wrong or revoked key returns HTTP 401. A missing, empty or unexpanded key is keyless: free tools only. MCP allows 60 requests a minute per key. A key cannot move funds or change limits.

See the MCP key guide and SingIt skill.

Tools

18 tools. The full reference with every parameter, allowed value, key scope and network is on the website, https://singitai.app/docs/mcp-tools/; docs/tools.md is the generated offline copy checked against the live server.

GroupToolsKey
Free lookupsget_price, list_price_symbols, list_modelsnone
Free answerschat_freenone
Chat (paid per call)chatyes, no extra scope
Your account (free, read-only)get_balance, get_limits, get_receiptsyes
Web (paid per call)web_search, read_pageyes, search scope
Market and data (paid per call)get_weather, get_singit_risk_check, get_x_profile, get_crypto_news, get_hyperliquid_market, get_funding_rates, resolve_ens, get_token_priceyes, tools scope

Paid calls are charged to the key's own limits, in USDC, including chat. Chat and web tools work on Base or Solana accounts; the market and data tools need a Base account for now. Read-only tools can still cost money, and repeating a paid call charges again. get_limits shows what the key has spent and what is left today.

Chat needs any valid key, with no extra scope. Send exactly one of prompt or messages; optional model is an ID from list_models without the free/ prefix. With prompt, you can also send system. max_tokens defaults to 1024 and can be up to 8192; reasoning models think inside that budget. SingIt's server enforces the key's daily and per-request caps for calls with that key to SingIt's MCP and /v1 only; a call over a cap is refused before anything is charged.

Check that it works

Configuration examples, not run live. Neither request needs a key and neither spends anything:

curl -sS https://app.singitai.app/mcp \

-H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' \ -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"check","version":"1.0"}}}'

curl -sS https://app.singitai.app/mcp \ -H 'Content-Type: application/json' -H 'Accept: application/json, text/event-stream' \ -d '{"jsonrpc":"2.0","id":2,"method":"tools/list"}'

Then ask the agent to call get_limits: it is free, read-only, and requires a key. It shows spent today, held amounts for running calls, remaining daily budget and expiry.

Or run the bundled check, which compares the live server with tools.json (Node 20+, no dependencies):

npm run check:live

What is in this repository

PathWhat
server.jsonThe MCP Registry manifest for app.singitai/singit
.mcp.json, llms-install.mdReady-made client config and an install guide meant for LLM clients
tools.jsonGateway-source snapshot pending deployment; refresh from live after deployment
docs/tools.mdOffline copy of the website's tools reference, generated from tools.json
scripts/check-live.mjsFree check of the live server against the snapshot

The server itself runs inside the SingIt gateway and shares code with the rest of the payment stack, so its source lives in the main repository (sign402-gateway). This repository is where you find out how to connect and what the server offers.

Contributing and security

See CONTRIBUTING.md. Security problems: email contact@singitai.app, not a public issue (SECURITY.md). MIT licensed.

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