What is CryoMCP?

CryoMCP enables users to query blockchain data using simple, natural language prompts directed to Claude. With direct access to real-time Ethereum data, Claude, through CryoMCP, can autonomously initiate queries, and perform complex data analyses.

CryoMCP empowers users to extract complex actionable insights from the blockchain without writing a single line of code.

On-chain micropayments

CryoMCP adopts the emerging x402 standard for agent-first commerce. This enables your AI-agent to make micropayments for individual data requests, offering a flexible, pay-per-query model. The payments are settled on Base and are paid in USDC.

With CryoMCP, your AI-agent gains full access to Ethereum state data, and only pays for the specific queries it executes.

Setup Required: Set your PRIVATE_KEY in the payflow configuration below. This wallet will be used to pay for cryo queries (0.05 USDC per query). It should be a wallet on Base with some USDC.

Claude Desktop Configuration

Add this to your claude_desktop_config.json:
{
  "mcpServers": {
    "cryo": {
      "command": "npx",
      "args": [
        "mcp-remote",
        "https://cryo-mcp.fly.dev/v1/mcp",
        "--header",
        "Authorization: none",
        "--transport",
        "http-only"
      ]
    },
    "payflow": {
      "command": "npx",
      "args": [
        "@chainbound/payflow-mcp"
      ],
      "env": {
        "PRIVATE_KEY": "",
        "MAX_PAYMENT_AMOUNT_USDC": "10"
      }
    }
  }
}
🔒 Security: The Payflow server runs entirely on your local machine. Your private key never leaves your computer and is only used locally for payment signing.

Available Tools

query_dataset
Query blockchain data and export to Parquet files, max 10,000 blocks at a time
help
Get help and usage instructions for all available tools
list_datasets
List all available cryo datasets (blocks, transactions, logs, etc.)
get_latest_block_number
Get the latest block number for recent data queries
describe_dataset
Get detailed schema information for any dataset
fetch_abi
Fetch the ABI for a contract to understand its interface
query_sql
Run DuckDB SQL queries against your exported data
describe_table
Describe the schema of a Parquet file
translate_event_signature
Decode hexadecimal event signatures to human-readable names

Examples

Example Prompt
Decode the logs of the following transaction: 0x899b8dcbb9c43dbbf20934cf6d620e72316e3a05a8cccd39a2e53759d6df0081

Please extract:
    • Swap metadata (e.g., tokens involved, amounts, path, DEX or router used)
    • Net token transfers between the user and the pool (clearly separating inflows and outflows)
[Local] Step 1: Claude reads your request, understands that it has to use the Cryo MCP server, and checks out the available tools and datasets. It then decides that it has to use the paid query_dataset tool to get the data.
[Local] Step 2: Claude asks the local Payflow MCP server to generate the signed micropayment payload, using the details it got from the query_dataset tool description.
[Local] Step 3: Claude calls the remote query_dataset tool with the signed transaction payload.
[Remote] Step 4: Cryo MCP verifies the payment validity via the Coinbase x402 facilitator, and if valid, executes the query and generates the Parquet results.
[Remote] Step 5: After the results have been generated successfully, the payment is settled and the resulting files are made available to Claude.
✅ Payment processed — paid 0.05 USDC
[Local] Step 6: Claude parses the dataset, executes some SQL queries, and compiles the final answer for you.
Answer
Transaction Analysis Summary
    Transaction Hash: 0x899b8dcbb9c43dbbf20934cf6d620e72316e3a05a8cccd39a2e53759d6df0081

Swap Details
    This transaction represents a SKY → WETH swap on Uniswap V3 where:

    User: 0xfbd4cdb413e45a52e2c8312f670e9ce67e794c37
    Pool: 0x764510ab1d39cf300e7abe8f5b8977d18f290628 (SKY/WETH Uniswap V3 Pool)
    Block: 22,639,515

Token Movements
    SKY Transfer (Log 769): User sent 95,067.95 SKY to the pool
    WETH Transfer (Log 768): Pool sent 2.772260 WETH to the user
    Swap Event (Log 770): Recorded the exchange with detailed metadata

Exchange Rate
    Rate: ~34,299 SKY per 1 WETH

Technical Metadata
    SqrtPriceX96: 428,287,079,139,934,610,832,547,040
    Liquidity: 565,170,137,150,867,722,820,494
    Tick: -17,536
Other Examples
Using Cryo, decode the following Ethereum transaction: 0x421..12cba Then, generate a Mermaid graph that illustrates the asset flow, including all participants (EOAs, contracts), asset types (ETH, tokens), and value amounts where applicable.

View the full response here.

flowchart TD A[User
0x053516...b07c6] -->|249.954 USDC| B[Router Contract
0x6088d9...c61d0
📋 Log 259: OrderRecord
Order Completed
USDC→ETH] B -->|249.954 USDC| C[Uniswap V3 Pool
0xe0554a...32939f
🔄 Log 256: Swap Event
Liquidity Updated
Tick: 0x3041f] C -->|0.0959 WETH| B B -->|0.0959 WETH| D[WETH Unwrapper
0x5703b6...9d4757] D -->|0.0959 WETH| E[WETH Contract
0xc02aaa...756cc2
📤 Log 254: Transfer Pool→Router
📤 Log 257: Transfer Router→Unwrapper
💸 Log 258: Withdrawal
WETH → ETH] E -->|0.0959 ETH| D D -->|0.0959 ETH| B B -->|0.0959 ETH| A F[USDC Contract
0xa0b869...6eb48
📤 Log 255: Transfer
From: User
To: Pool
Amount: 249.954 USDC] -.->|Transfer Log| C G[Log Details:
Log 253: Router State Update
Log 254: WETH Transfer Pool→Router
95,945,406,736,825,197 wei
Log 255: USDC Transfer User→Pool
249,954,047 units
Log 256: Uniswap V3 Swap
SqrtPrice: 0x4c848676a313cb7a0b8d33ab50e6
Liquidity: 0x9f690c99a7cbc4
Log 257: WETH Transfer Router→Unwrapper
95,945,406,736,825,197 wei
Log 258: WETH Withdrawal
Unwrapper: 0x5703b6...
Log 259: OrderRecord Complete
TokenIn: USDC TokenOut: ETH] style A fill:#e1f5fe style B fill:#f3e5f5 style C fill:#e8f5e8 style D fill:#fff3e0 style E fill:#fce4ec style F fill:#e3f2fd style G fill:#f1f8e9 classDef tokenflow stroke:#2196f3,stroke-width:3px classDef ethflow stroke:#ff9800,stroke-width:3px classDef loginfo stroke:#4caf50,stroke-width:2px class A,B,C,D,E,F tokenflow class G loginfo
Using Cryo, analyze the last 100 Ethereum blocks and detect any suspicious transactions.

View the full response here.

The analysis of the last 100 blocks has revealed several highly suspicious transaction patterns that warrant immediate attention. 
Here are the key findings:

Most Critical Concerns:
1. Massive ETH Transfer (2,654 ETH)
    A single transaction moved $6.6M worth of ETH, which is extremely unusual
    The sender address has been highly active with 110 transactions moving 2,745 ETH total

2. Failed Exploit Attempts
    One address made 6+ repeated failed attempts against the same contract
    Each attempt burned ~416K gas, suggesting automated exploitation attempts

3. MEV Bot Manipulation
    Detected extreme gas price manipulation (578 Gwei vs normal 15 Gwei)
    Clear evidence of front-running and sandwich attack attempts

4. Coordinated Transfer Chain
    Suspicious sequence of large transfers (1,071→1,161→1,161 ETH) that could indicate money laundering

The analysis processed 20,158 transactions and identified multiple high-risk addresses and contracts that should be monitored closely. 
The report above contains specific transaction hashes, addresses, and detailed patterns for further investigation.
Would you like me to dive deeper into any specific suspicious pattern or analyze additional data like contract interactions or token transfers?
Using Cryo, return all storage slots that were read from or written to by the following transaction: 0x3..fde. Include both the slot addresses and whether they were read or modified.

View the full response here.