High Risk →

cast_nonce

Query the transaction nonce of an address (cast nonce). Note: on zkSync this returns the TX nonce only, not the deploy nonce.

Part of the Foundry Zksync MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

foundry-zksync-mcp Execute Risk 3/5

AI agents invoke cast_nonce to trigger processes or run actions in Foundry Zksync. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.

cast_nonce can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. Intercept enforces rate limits and validates arguments to keep execution within safe bounds.

Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.

io-github-jrigada-foundry-zksync.yaml
tools:
  cast_nonce:
    rules:
      - action: allow
        rate_limit:
          max: 10
          window: 60
        validate:
          required_args: true

See the full Foundry Zksync policy for all 21 tools.

Tool Name cast_nonce
Category Execute
Risk Level High

View all 21 tools →

Agents calling execute-class tools like cast_nonce have been implicated in these attack patterns. Read the full case and prevention policy for each:

Browse the full MCP Attack Database →

Other tools in the Execute risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.

cast_nonce is one of the high-risk operations in Foundry Zksync. For the full severity-focused view — only the high-risk tools with their recommended policies — see the breakdown for this server, or browse all high-risk tools across every MCP server.

What does the cast_nonce tool do? +

Query the transaction nonce of an address (cast nonce). Note: on zkSync this returns the TX nonce only, not the deploy nonce.. It is categorised as a Execute tool in the Foundry Zksync MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cast_nonce? +

Add a rule in your Intercept YAML policy under the tools section for cast_nonce. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Foundry Zksync MCP server.

What risk level is cast_nonce? +

cast_nonce is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit cast_nonce? +

Yes. Add a rate_limit block to the cast_nonce rule in your Intercept policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block cast_nonce completely? +

Set action: deny in the Intercept policy for cast_nonce. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides cast_nonce? +

cast_nonce is provided by the Foundry Zksync MCP server (foundry-zksync-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policies on Foundry Zksync

Open source. One binary. Zero dependencies.

npx -y @policylayer/intercept
github.com/policylayer/intercept →
// GET IN TOUCH

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