Falcon Shield
Pre-sign Solana tx guard for agents: ALLOW/WARN/BLOCK verdict, x402 USDC pay-per-call.
Should I use this
Quality & Safety
Based on automated analysis of tool definitions and protocol compliance.
Context Cost
This is the approximate number of tokens consumed each time the server's tools are loaded into a model's context. Higher counts reduce the attention available for other tasks.
Install
One-Click Install
Add this to your `claude_desktop_config.json` file:
{
"mcpServers": {
"falcon-shield": {
"url": "https://falcon-shield.falcon-sol.workers.dev/mcp"
}
}
}Remote endpoints
https://falcon-shield.falcon-sol.workers.dev/mcpstreamable-httpWhat it can do
Tool inventory
Tools (1)
🟢shield_guard_check(tx, wallet, known_addresses, quote, cap_base_units, ...)
Use this before an agent or wallet signs a Solana transaction. Decodes the unsigned or signed transaction and returns NO_MATCH (no known-bad pattern matched; not a safety guarantee), WARN, or BLOCK, with plain-language reasons and a signed receipt. Pass an x402 quote to also check a payment transaction against it (overpay, approve-instead-of-transfer, unchecked Transfer, wrong payee). Errors return ERROR and are never charged. Price $0.009 USDC (x402, Solana).
Input Schema
{
"type": "object",
"properties": {
"tx": {
"type": "string",
"description": "Base64 wire transaction (also accepts an RPC getTransaction result)."
},
"wallet": {
"type": "string",
"description": "Your own pubkey; only this key is treated as 'you'."
},
"known_addresses": {
"type": "array",
"items": {
"type": "string"
},
"maxItems": 200,
"description": "Optional: pubkeys you have recently paid or received from. A recipient that only looks like one of these (same first/last characters) is flagged as address poisoning."
},
"quote": {
"type": "object",
"description": "x402 quote the tx pays: {asset, amount, pay_to | pay_to_token_account, decimals?, token_program?}."
},
"cap_base_units": {
"type": "integer",
"description": "Hard per-payment cap enforced even if the quote asks for more."
},
"caps": {
"type": "object",
"description": "Optional spend caps you declare; any violation returns BLOCK. Keys: max_amount (int base units per outflow), max_amounts ({mint|'SOL': int}), max_total (int per asset), allowed_payees ([pubkey]; owners' ATAs match), allowed_assets ([mint|'SOL']), allow_approvals (bool, default false)."
},
"simulate": {
"type": "boolean",
"description": "Simulate against Solana mainnet (Helius RPC, sigVerify off, recent blockhash replaced, never submitted). Default true; false = static checks only. If simulation fails the verdict is at least WARN, except plain System/Token/ATA/ComputeBudget/Memo transactions with no unresolved lookup tables, which are fully decoded statically. Third-party unlimited approvals BLOCK by default. Response includes risk_score (0-100), basis (simulated|static) and top_reason."
},
"strict": {
"type": "boolean",
"description": "Escalate HIGH-risk token approvals (unlimited or third-party delegate) from WARN to BLOCK. Default false."
}
},
"required": [
"tx"
]
}Community
Evidence