Modify the URI of a dynamic NFT (dNFT) on the XRP Ledger. The NFT must have been minted with the tfMutable flag enabled. Only the issuer or their authorized minter can modify the URI.
AI agents use nft-modify to create or update resources in Xrpl mcp — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Xrpl mcp environment.
This tool modifies NFT metadata (the URI field) on the XRP Ledger. While it changes state, the modification is reversible (the URI can be changed again), distinguishing it from destructive operations. It does not delete data, execute arbitrary code, or involve financial transactions. The authorization requirement and XRP Ledger integration suggest it's scoped to NFT ownership.
From the tool's definition Tool description states it "Modify[s] the URI of a dynamic NFT" - a reversible modification of data on the ledger. The operation requires authorization (issuer or authorized minter only) and affects NFT metadata.
Documented attack patterns abuse exactly the kind of access nft-modify gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Xrpl mcp, and nothing reaches the server without passing your rules. This is the rule we recommend for nft-modify:
{
"version": "1",
"default": "deny",
"tools": {
"nft-modify": {
"limits": [
{
"counter": "nft-modify_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}nft-modify 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.
Free to start. No card required.
Modify the URI of a dynamic NFT (dNFT) on the XRP Ledger. The NFT must have been minted with the tfMutable flag enabled. Only the issuer or their authorized minter can modify the URI. It is categorised as a Write tool in the Xrpl mcp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Xrpl MCP server in PolicyLayer and add a rule for nft-modify: 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 Xrpl mcp. Nothing to install.
nft-modify 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 nft-modify 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 nft-modify. 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.
nft-modify is provided by the Xrpl MCP server (romthpt/mcp-xrpl). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Xrpl mcp, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
71 Xrpl mcp tools catalogued and risk-classified — across an index of 43,000+ MCP servers.