After the on-chain approveHash tx has been mined (broadcast via send_transaction from the receipt of prepare_safe_tx_propose or prepare_safe_tx_approve), post the signature to Safe Transaction Service. Verifies on-chain that approvedHashes(signer, safeTxHash) != 0 first — refuses to post when the...
AI agents use submit_safe_tx_signature to create or update resources in VaultPilot MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your VaultPilot MCP environment.
| Parameter | Type | Required | Description |
|---|---|---|---|
chain | string | — | |
signer | string | Yes | |
safeTxHash | string | Yes | |
safeAddress | string | Yes |
Parameters from the server's own tool schema.
An AI agent can call submit_safe_tx_signature faster than any human can review — one bad instruction and it creates or modifies resources in VaultPilot MCP by the hundred, each call as confident as the last.
Attacks that exploit this kind of access
After the on-chain approveHash tx has been mined (broadcast via send_transaction from the receipt of prepare_safe_tx_propose or prepare_safe_tx_approve), post the signature to Safe Transaction Service. Verifies on-chain that approvedHashes(signer, safeTxHash) != 0 first — refuses to post when the underlying approval doesn't exist yet. Auto-detects whether to call proposeTransaction (creates a new queue entry — when this server proposed the tx) or confirmTransaction (adds a signature to an existing entry — when another client proposed it). Returns the Safe Web UI deep-link so the user / co-signers can see the queue state. It is categorised as a Write tool in the VaultPilot MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
submit_safe_tx_signature accepts 4 parameters: chain, signer, safeTxHash, safeAddress. Required: signer, safeTxHash, safeAddress. The full parameter table on this page comes from the server's own tool schema.
Register the VaultPilot MCP server in PolicyLayer and add a rule for submit_safe_tx_signature: 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 VaultPilot MCP. Nothing to install.
submit_safe_tx_signature is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the submit_safe_tx_signature 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 submit_safe_tx_signature. 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.
submit_safe_tx_signature is provided by the VaultPilot MCP server (vaultpilot-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.