AI agents invoke forge_script to trigger actions in Foundry MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
This is classified as Execute (not Destructive) because the actual impact depends on what the script contains—it could read data, modify state, or destroy data. However, given the onchain blockchain context and that Forge scripts typically have broad capabilities to interact with smart contracts and the blockchain, the severity is critical due to potential for irreversible financial and state-altering consequences…
From the tool's definition Tool allows running arbitrary Forge scripts via 'Run a Forge script from the workspace'. Forge scripts can execute arbitrary code, deploy contracts, modify blockchain state, and interact with smart contracts in unpredictable ways depending on script contents.
Documented attack patterns abuse exactly the kind of access forge_script gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Foundry MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for forge_script:
{
"version": "1",
"default": "deny",
"tools": {
"forge_script": {
"limits": [
{
"counter": "forge_script_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}forge_script stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Run a Forge script from the workspace. It is categorised as a Execute tool in the Foundry MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Foundry MCP Server MCP server in PolicyLayer and add a rule for forge_script: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Foundry MCP Server. Nothing to install.
forge_script is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the forge_script rule in your PolicyLayer 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.
Set action: deny in the PolicyLayer policy for forge_script. 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.
forge_script is provided by the Foundry MCP Server MCP server (praneshasp/foundry-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 16 Foundry MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
16 Foundry MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.