Send audio/voice messages to a WhatsApp chat. Supports URL or base64 data.
AI agents use waha_send_audio to create or update resources in WAHA MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your WAHA MCP Server environment.
Sending messages is a write operation—it creates data in WhatsApp chats that can be modified or deleted later. While the blast radius is significant (an AI could spam messages, impersonate users, or disrupt conversations at scale), it is not destructive (irreversible deletion), financial, or execute-class (arbitrary code/command).
From the tool's definition Tool enables sending audio messages to WhatsApp chats. The description explicitly states 'Send audio/voice messages' which creates new message content in a chat, a reversible write operation.
Documented attack patterns abuse exactly the kind of access waha_send_audio gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and WAHA MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for waha_send_audio:
{
"version": "1",
"default": "deny",
"tools": {
"waha_send_audio": {
"limits": [
{
"counter": "waha_send_audio_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} waha_send_audio 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.
Send audio/voice messages to a WhatsApp chat. Supports URL or base64 data. It is categorised as a Write tool in the WAHA MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the WAHA MCP Server MCP server in PolicyLayer and add a rule for waha_send_audio: 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 WAHA MCP Server. Nothing to install.
waha_send_audio 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 waha_send_audio 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 waha_send_audio. 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.
waha_send_audio is provided by the WAHA MCP Server MCP server (seejux/waha-whatsapp-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from WAHA MCP Server, 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.
52 WAHA MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.