prepare_tron_trc20_approve

SERVERVaultPilot MCP SOURCEvaultpilot-mcp

Medium RISK CLASS

Category Write

Parameters 64 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-szhygulin-vaultpilot-mcp/prepare-tron-trc20-approve.md

WHAT IT DOES

What prepare_tron_trc20_approve does on VaultPilot MCP

AI agents use prepare_tron_trc20_approve 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
`from`	string	Yes	Base58 TRON owner address — the wallet that holds the tokens.
`token`	string	Yes	Base58 TRC-20 contract address. Any TRC-20 is accepted; non-canonical tokens require `decimals`.
`amount`	string	Yes	Allowance amount as a human-readable decimal string. Pass exactly the amount you intend to swap, NOT "max" / unbounded — TRC-20 unbounded approvals are a known
`spender`	string	Yes	Base58 TRON address authorized to pull tokens via transferFrom. Typical use: the LiFi Diamond on TRON (TU3ymitEKCWQFtASkEeHaPb8NfZcJtCHLt) for `prepare_tron_lif
`decimals`	integer	—	Token decimals. OPTIONAL when `token` is in the canonical TRC-20 set (USDT/USDC=6, USDD/TUSD=18 — auto-resolved). REQUIRED for any other TRC-20 contract; we ref
`feeLimitTrx`	string	—	Optional fee-limit override in TRX. Defaults to 100 TRX (TronLink/Ledger Live standard).

Parameters from the server's own tool schema.

RISK

Why prepare_tron_trc20_approve is rated Medium

This tool creates a transaction that modifies token allowance state on-chain, enabling a third party (spender) to transfer tokens on behalf of the user. While the transaction is unsigned (requiring additional authorization), it constructs an irreversible financial commitment once signed and broadcast.

From the tool's definition Build an unsigned TRC-20 approve(spender, amount) tx — sets allowance so a third party can pull tokens via transferFrom. Authorize the LiFi Diamond on TRON to pull tokens.

Risk signalsHandles credentials or secrets (token)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs prepare_tron_trc20_approve safely

PolicyLayer is an MCP gateway: it sits between your AI agents and VaultPilot MCP, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For prepare_tron_trc20_approve, this is the rule to start with:

prepare_tron_trc20_approve Rate-limited

prepare_tron_trc20_approve stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "prepare_tron_trc20_approve": {
      "limits": [
        {
          "counter": "prepare_tron_trc20_approve_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect VaultPilot MCP, apply this rule, and every prepare_tron_trc20_approve call is checked against it from then on.

FAQ

Questions about prepare_tron_trc20_approve

What does the prepare_tron_trc20_approve tool do? +

Build an unsigned TRC-20 approve(spender, amount) tx — sets allowance so a third party can pull tokens via transferFrom. Primary use: authorize the LiFi Diamond on TRON (TU3ymitEKCWQFtASkEeHaPb8NfZcJtCHLt) before running prepare_tron_lifi_swap with a TRC-20 source token (LiFi's quote response assumes the approve already exists; insufficient allowance reverts the swap on-chain). Accepts ANY TRC-20 contract — not just the canonical set. Decimals are auto-resolved for canonical USDT/USDC/USDD/TUSD; for any other TRC-20 you MUST pass decimals explicitly. We REFUSE to default decimals on approve because an off-by-power-of-ten allowance silently authorizes a 10^12-fold larger spend than intended, with no UX recovery on a Ledger blind-sign flow. amount is a human decimal string ("100" = 100 tokens at the resolved decimals). "max" / unbounded approvals are NOT supported — pass exactly the amount you intend to swap. Returns a preview + opaque handle for send_transaction. 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.

What parameters does prepare_tron_trc20_approve accept? +

prepare_tron_trc20_approve accepts 6 parameters: from, token, amount, spender, decimals, feeLimitTrx. Required: from, token, amount, spender. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on prepare_tron_trc20_approve? +

Register the VaultPilot MCP server in PolicyLayer and add a rule for prepare_tron_trc20_approve: 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.

What risk level is prepare_tron_trc20_approve? +

prepare_tron_trc20_approve is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit prepare_tron_trc20_approve? +

Yes. Add a rate_limit block to the prepare_tron_trc20_approve 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.

How do I block prepare_tron_trc20_approve completely? +

Set action: deny in the PolicyLayer policy for prepare_tron_trc20_approve. 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 prepare_tron_trc20_approve? +

prepare_tron_trc20_approve 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.

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