Build an unsigned MarginFi REPAY tx against outstanding debt in the named bank. Pass repayAll: true to repay the full outstanding debt (also clears the balance slot). DURABLE NONCE + prepare_marginfi_init prerequisites identical to prepare_marginfi_supply. BLIND-SIGN on Ledger.
AI agents invoke prepare_marginfi_repay to trigger actions in VaultPilot MCP. 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.
| Parameter | Type | Required | Description |
|---|---|---|---|
mint | object | — | Base58 SPL mint address. Used as an override or when the token isn't in the canonical SOLANA_TOKENS table. Exactly one of `symbol` or `mint` must be passed. |
amount | string | Yes | Human-readable decimal amount to repay against outstanding debt in this bank. |
symbol | string | — | Canonical token symbol (USDC, SOL, USDT, JUP, BONK, JTO, mSOL, jitoSOL). The builder resolves this to the underlying mint; MarginFi treats SOL as wSOL internall |
wallet | string | Yes | Base58 Solana mainnet address (ed25519 pubkey, 43 or 44 chars). |
repayAll | boolean | — | Set true to repay the full outstanding debt in this bank (SDK also clears the balance slot — cheaper for the user if they're closing out). Omit for partial. |
accountIndex | integer | — | MarginfiAccount slot (0 = first, 1 = second, ...). Most users stay on 0. Use a different index to segregate positions across multiple MarginfiAccounts owned by |
Parameters from the server's own tool schema.
prepare_marginfi_repay triggers real processes with real consequences. An agent gone sideways doesn't fire it once — it starts dozens of builds, sends mass notifications, or burns through compute before anyone looks up.
Attacks that exploit this kind of access
Build an unsigned MarginFi REPAY tx against outstanding debt in the named bank. Pass repayAll: true to repay the full outstanding debt (also clears the balance slot). DURABLE NONCE + prepare_marginfi_init prerequisites identical to prepare_marginfi_supply. BLIND-SIGN on Ledger. It is categorised as a Execute tool in the VaultPilot MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
prepare_marginfi_repay accepts 6 parameters: mint, amount, symbol, wallet, repayAll, accountIndex. Required: amount, wallet. 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 prepare_marginfi_repay: 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.
prepare_marginfi_repay 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 prepare_marginfi_repay 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 prepare_marginfi_repay. 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.
prepare_marginfi_repay 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.