Sardis MCP Server

The Sardis MCP (Model Context Protocol) server enables AI agents running in Claude Desktop, Cursor, and other MCP-compatible clients to execute secure payments with built-in policy validation.

What is MCP?

MCP (Model Context Protocol) is an open protocol that standardizes how AI assistants communicate with external tools and data sources. The Sardis MCP server exposes payment capabilities as tools that can be safely used by AI agents.

Installation

npm install -g @sardis/mcp-server

Or use npx without installation:

npx @sardis/mcp-server

Claude Desktop Configuration

Add Sardis to your Claude Desktop configuration:

macOS

Edit ~/Library/Application Support/Claude/claude_desktop_config.json:

{
  "mcpServers": {
    "sardis": {
      "command": "npx",
      "args": ["-y", "@sardis/mcp-server"],
      "env": {
        "SARDIS_API_KEY": "sk_live_...",
        "SARDIS_WALLET_ID": "wallet_...",
        "SARDIS_MODE": "live"
      }
    }
  }
}

Windows

Edit %APPDATA%\Claude\claude_desktop_config.json:

{
  "mcpServers": {
    "sardis": {
      "command": "npx",
      "args": ["-y", "@sardis/mcp-server"],
      "env": {
        "SARDIS_API_KEY": "sk_live_...",
        "SARDIS_WALLET_ID": "wallet_...",
        "SARDIS_MODE": "live"
      }
    }
  }
}

Simulation Mode (No API Key Required)

For testing without real transactions:

{
  "mcpServers": {
    "sardis": {
      "command": "npx",
      "args": ["-y", "@sardis/mcp-server"],
      "env": {
        "SARDIS_MODE": "simulated"
      }
    }
  }
}

Cursor Configuration

Add Sardis to Cursor’s MCP settings:

Open Cursor Settings (Cmd+, on Mac, Ctrl+, on Windows)
Navigate to Features → MCP
Add new MCP server:

{
  "sardis": {
    "command": "npx",
    "args": ["-y", "@sardis/mcp-server"],
    "env": {
      "SARDIS_API_KEY": "sk_live_...",
      "SARDIS_WALLET_ID": "wallet_...",
      "SARDIS_MODE": "live"
    }
  }
}

Environment Variables

Variable	Required	Description	Default
`SARDIS_API_KEY`	Yes (live mode)	Your Sardis API key	-
`SARDIS_WALLET_ID`	Recommended	Default wallet ID	-
`SARDIS_AGENT_ID`	Optional	Agent ID for attribution	-
`SARDIS_MODE`	Optional	`live` or `simulated`	`simulated`
`SARDIS_API_URL`	Optional	API base URL	`https://api.sardis.sh`
`SARDIS_CHAIN`	Optional	Default blockchain	`base_sepolia`
`SARDIS_POLICY_BLOCKED_VENDORS`	Optional	Comma-separated blocked vendors	-
`SARDIS_POLICY_ALLOWED_VENDORS`	Optional	Comma-separated allowed vendors	-
`SARDIS_REQUIRE_EXPLICIT_APPROVAL`	Optional	Require vendor approval	`false`

Available Tools

The MCP server exposes 50+ tools across multiple categories:

Wallet Operations

sardis_get_wallet - Get wallet information
sardis_get_balance - Check wallet balance and limits
sardis_create_wallet - Create a new wallet
sardis_list_wallets - List all wallets

Payment Operations

sardis_pay - Execute a payment
sardis_get_transaction - Get transaction details
sardis_list_transactions - List transaction history

Hold Operations (Pre-Authorization)

sardis_create_hold - Create a payment hold
sardis_capture_hold - Capture (settle) a hold
sardis_void_hold - Cancel a hold
sardis_release_hold - Release hold funds
sardis_get_hold - Get hold details
sardis_list_holds - List all holds
sardis_extend_hold - Extend hold expiration

Policy & Guardrails

sardis_check_policy - Validate payment against policy
sardis_validate_limits - Check spending limits
sardis_check_compliance - Run compliance checks
sardis_get_policies - List active policies

Agent Management

sardis_create_agent - Create a new agent
sardis_get_agent - Get agent details
sardis_list_agents - List all agents
sardis_update_agent - Update agent information

Group Management

sardis_create_group - Create agent group
sardis_get_group - Get group details
sardis_list_groups - List all groups
sardis_add_agent_to_group - Add agent to group
sardis_remove_agent_from_group - Remove agent from group
sardis_get_group_spending - Get group spending summary

Virtual Cards

sardis_issue_card - Issue a virtual card
sardis_create_card - Create a card
sardis_get_card - Get card details
sardis_list_cards - List all cards
sardis_freeze_card - Freeze a card
sardis_unfreeze_card - Unfreeze a card
sardis_cancel_card - Cancel a card

Fiat Operations

sardis_fund_wallet - Add funds via ACH
sardis_withdraw_to_bank - Withdraw to bank account
sardis_withdraw - Withdraw funds
sardis_get_funding_status - Check funding status
sardis_get_withdrawal_status - Check withdrawal status
sardis_list_funding_transactions - List funding history

Approval Workflows

sardis_request_approval - Request payment approval
sardis_get_approval_status - Check approval status
sardis_check_approval - Verify approval
sardis_list_pending_approvals - List pending approvals
sardis_cancel_approval - Cancel approval request

Spending Analytics

sardis_get_spending_summary - Get spending overview
sardis_get_spending - Get detailed spending
sardis_get_spending_by_vendor - Spending by vendor
sardis_get_spending_by_category - Spending by category
sardis_get_spending_trends - Analyze spending trends

Sandbox & Testing

sardis_sandbox_demo - Interactive sandbox demo

Usage Examples

In Claude Desktop

Once configured, you can ask Claude to make payments:

You: Pay $50 to OpenAI for API usage

Claude: I'll help you make that payment. Let me first check the policy 
and balance.

[Uses sardis_check_policy and sardis_get_balance]

The payment is within your limits. I'll proceed with the payment.

[Uses sardis_pay]

Payment successful! Transaction hash: 0x123...

Policy Validation Example

You: Can I spend $500 on AWS?

Claude: Let me check your spending limits.

[Uses sardis_validate_limits]

Yes, you have $750 remaining in your daily limit. The $500 payment 
to AWS would be approved.

Hold Example (Hotel Booking)

You: Create a $200 hold for my hotel booking

Claude: I'll create a pre-authorization hold.

[Uses sardis_create_hold]

Hold created successfully:
- Hold ID: hold_abc123
- Amount: $200 USDC
- Expires: In 24 hours
- Status: Active

When you check out, I can capture the final amount or void the hold 
if you cancel.

Group Spending Example

You: How much has my AI research team spent today?

Claude: Let me check the group spending.

[Uses sardis_get_group_spending]

AI Research Team spending today:
- Total spent: $2,450 / $5,000 daily limit
- Remaining: $2,550
- Transactions: 18
- Active agents: 5

Prompt Templates

The MCP server provides built-in prompts:

`pay-vendor`

Make a payment with policy validation:

Arguments:
- vendor: Vendor name (e.g., openai, anthropic)
- amount: Amount in USD
- purpose: Payment purpose (optional)

`check-balance`

Check wallet balance and spending limits:

No arguments required

`sandbox-tour`

Guided tour of Sardis capabilities:

Arguments:
- category: Focus area (quickstart, payments, cards, policy, holds, fiat, or all)

Resources

The MCP server exposes resources for context:

sardis://wallet/balance - Current wallet balance and limits
sardis://wallet/info - Wallet configuration
sardis://config - Server configuration status
sardis://tools - List of available tools

Security Features

Rate Limiting

Per-tool rate limits prevent abuse:

Payment operations: 5 calls/minute
Wallet mutations: 3 calls/minute
Hold operations: 10 calls/minute
Read operations: 60 calls/minute

Policy Enforcement

All payment operations go through policy validation:

Check spending limits
Validate vendor/recipient
Run compliance checks
Verify wallet balance

Audit Trail

All operations are logged with:

Timestamp
Tool name
Arguments
Result
Request ID

Troubleshooting

Server Not Appearing in Claude

Check config file location
Verify JSON syntax
Restart Claude Desktop
Check Claude logs: ~/Library/Logs/Claude/mcp*.log

”API Key Not Configured” Error

Verify SARDIS_API_KEY in config
Check API key format (starts with sk_)
Ensure no extra spaces or quotes

”Wallet Not Found” Error

Set SARDIS_WALLET_ID environment variable
Create a wallet first using sardis_create_wallet
Use simulation mode for testing

Rate Limit Exceeded

Check rate limit window (1 minute)
Reduce request frequency
Contact support for higher limits

Development

Run the MCP server locally:

git clone https://github.com/sardis-pay/sardis.git
cd sardis/packages/sardis-mcp-server
pnpm install
pnpm dev

Support

Documentation: https://sardis.sh/docs
GitHub Issues: https://github.com/sardis-pay/sardis/issues
Email: [email protected]

Official SDKs

SDK Reference

​Sardis MCP Server

​What is MCP?

​Installation

​Claude Desktop Configuration

​macOS

​Windows

​Simulation Mode (No API Key Required)

​Cursor Configuration

​Environment Variables

​Available Tools

​Wallet Operations

​Payment Operations

​Hold Operations (Pre-Authorization)

​Policy & Guardrails

​Agent Management

​Group Management

​Virtual Cards

​Fiat Operations

​Approval Workflows

​Spending Analytics

​Sandbox & Testing

​Usage Examples

​In Claude Desktop

​Policy Validation Example

​Hold Example (Hotel Booking)

​Group Spending Example

​Prompt Templates

​pay-vendor

​check-balance

​sandbox-tour

​Resources

​Security Features

​Rate Limiting

​Policy Enforcement

​Audit Trail

​Troubleshooting

​Server Not Appearing in Claude

​”API Key Not Configured” Error

​”Wallet Not Found” Error

​Rate Limit Exceeded

​Development

​Support

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