Compose a multi-party multi-asset send transaction. Sends multiple assets to multiple destinations in a single transaction. All three arrays must be the same length.
Part of the 21e14 server.
Free to start. No card required.
AI agents use compose_mpma to create or modify resources in 21e14. Write operations carry medium risk because an autonomous agent could trigger bulk unintended modifications. Rate limits prevent a single agent session from making hundreds of changes in rapid succession. Argument validation ensures the agent passes expected values.
Without a policy, an AI agent could call compose_mpma repeatedly, creating or modifying resources faster than any human could review. PolicyLayer's rate limiting ensures write operations happen at a controlled pace, and argument validation catches malformed or unexpected inputs before they reach 21e14.
Write tools can modify data. A rate limit prevents runaway bulk operations from AI agents.
{
"version": "1",
"default": "deny",
"tools": {
"compose_mpma": {
"limits": [
{
"counter": "compose_mpma_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}See the full 21e14 policy for all 48 tools.
These attack patterns abuse exactly the kind of access compose_mpma gives an agent. Each links to the full case and the policy that stops it:
Other write tools across the catalogue. The same approach applies to each: rate-limit and validate the arguments.
Compose a multi-party multi-asset send transaction. Sends multiple assets to multiple destinations in a single transaction. All three arrays must be the same length.. It is categorised as a Write tool in the 21e14 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the 21e14 MCP server in PolicyLayer and add a rule for compose_mpma: 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 21e14. Nothing to install.
compose_mpma 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 compose_mpma 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 compose_mpma. 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.
compose_mpma is provided by the 21e14 MCP server (@21e14/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 48 21e14 tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.