Docs · MCP

Connect over MCP

Add one server and your agent can search Strale’s tools and call them. Free tools need no key.

Add the server

Strale runs a hosted MCP server at https://api.strale.io/mcp (streamable HTTP, no install). You can also run the strale-mcp package on your machine over stdio.

{
  "mcpServers": {
    "strale": {
      "type": "streamableHttp",
      "url": "https://api.strale.io/mcp"
    }
  }
}

{
  "mcpServers": {
    "strale": {
      "type": "streamableHttp",
      "url": "https://api.strale.io/mcp",
      "headers": {
        "Authorization": "Bearer sk_live_your_key_here"
      }
    }
  }
}

{
  "mcpServers": {
    "strale": {
      "command": "npx",
      "args": [
        "-y",
        "strale-mcp"
      ],
      "env": {
        "STRALE_API_KEY": "sk_live_your_key_here"
      }
    }
  }
}

# Hosted, no key (free tools)
claude mcp add --transport http strale https://api.strale.io/mcp

# Hosted, with your key
claude mcp add --transport http strale https://api.strale.io/mcp --header "Authorization: Bearer $STRALE_API_KEY"

# Local
claude mcp add strale --env STRALE_API_KEY=$STRALE_API_KEY -- npx -y strale-mcp

Claude Desktop. For the hosted server, add https://api.strale.io/mcp as a custom connector under Settings → Connectors. For the local server, merge the Local (npx) JSON into claude_desktop_config.json and restart the app. On macOS the file is in ~/Library/Application Support/Claude/; on Windows it is in %APPDATA%\Claude\.
Cursor. Put the same JSON in .cursor/mcp.json.
Any other MCP client. Point it at https://api.strale.io/mcp over streamable HTTP. To use a key, send Authorization: Bearer with it.
Local. Needs Node.js 20 or later. The server reads STRALE_API_KEY from its environment. Leave it out to use free tools only.

Variable	Default	Meaning
`STRALE_API_KEY`	none	Your API key. Needed for paid tools and `strale_balance`.
`STRALE_BASE_URL`	`https://api.strale.io`	The API the server calls.
`STRALE_MAX_PRICE_CENTS`	`200`	The price ceiling, in euro cents, sent with every `strale_execute` call that does not set its own.

  Make your first call
   Restart your client
 Use the “Hosted, no key” config. The client lists Strale’s tools once it reconnects.
 
  Ask for a free tool
 Type this into the client.
   Prompt  
  Use Strale to run iban-validate on {"iban":"SE4550000000058398257466"}.
 
  
 
  Watch the call
 The agent calls strale_execute. This is what it sends.
   Tool call  
  {
  "tool": "strale_execute",
  "arguments": {
    "slug": "iban-validate",
    "inputs": {
      "iban": "SE4550000000058398257466"
    }
  }
}
 
  
 
  Read the result
 The result carries the tool’s output, the price charged (0 for a free tool), the latency and the provenance. The tool’s published example:
   Output  
  {
  "bban": "50000000058398257466",
  "valid": true,
  "bank_code": "500",
  "branch_code": null,
  "check_digits": "45",
  "country_code": "SE",
  "expected_length": 24
}
 
  
 Without a key, free tools allow 300 calls a month per IP address across all free tools.
 
 
 
  The tools it adds
 The server adds 9 tools that cover the whole catalogue. The agent finds a tool with strale_search and runs it with strale_execute, so your client’s tool list stays short.
   Tool What it does Key needed
  strale_search Finds tools by keyword or category. Returns slug, price and input fields. No
strale_execute Runs a tool by slug with its inputs. Takes an optional max_price_cents, default 200 (€2.00). Free tools: no. Paid tools: yes
strale_getting_started Lists the free tools with example inputs, and the ways to pay. No
strale_trust_profile Returns a tool’s last test, test history, limitations and source. No
strale_methodology Returns how Strale tests tools and keeps audit records. No
strale_transaction Returns a past call by transaction ID. Paid calls: yes
strale_balance Returns your wallet balance in euro cents. Yes
strale_ping Checks that the server is up and reports its version and tool counts. No
strale_web3_assurance Checks an on-chain counterparty (wallet, contract, token, protocol or bridge) in one call. See the tool’s page
 
 
 
 A tool that runs longer than 10 seconds returns a transaction_id and a poll_url. Call strale_transaction with the ID until the status is completed or failed.
 
  Use paid tools
   Get a key
 Sign up for an API key. New accounts start with a small trial balance.
 
  Add it to the config
 Use the “Hosted, with key” config, or set STRALE_API_KEY for the local server. Restart the client.
 
  Cap what the agent can spend
 Every strale_execute call carries a price ceiling, €2.00 unless you set max_price_cents or STRALE_MAX_PRICE_CENTS. A tool that costs more is refused before it runs. Account-wide limits are in Retry safely and cap spend.
 
 
 With no key, a paid tool answers with the ways to pay: an API key, or a pay-per-request x402 payment with no signup. See x402.
  Browse tools Back to Docs

Tool	What it does	Key needed
`strale_search`	Finds tools by keyword or category. Returns slug, price and input fields.	No
`strale_execute`	Runs a tool by slug with its inputs. Takes an optional max_price_cents, default 200 (€2.00).	Free tools: no. Paid tools: yes
`strale_getting_started`	Lists the free tools with example inputs, and the ways to pay.	No
`strale_trust_profile`	Returns a tool’s last test, test history, limitations and source.	No
`strale_methodology`	Returns how Strale tests tools and keeps audit records.	No
`strale_transaction`	Returns a past call by transaction ID.	Paid calls: yes
`strale_balance`	Returns your wallet balance in euro cents.	Yes
`strale_ping`	Checks that the server is up and reports its version and tool counts.	No
`strale_web3_assurance`	Checks an on-chain counterparty (wallet, contract, token, protocol or bridge) in one call.	See the tool’s page