AI Agent Infrastructure

The Email API for Autonomous Agents

Equip your LLMs, autonomous workflows, and agent swarms with secure, reliable, and compliant email delivery. Safety guardrails and prompt safety filters included.

Structured JSON Outputs

Ensure your agents always generate structurally sound emails. Validate body templates, target list JSON arrays, and attachments dynamically against schemas before hitting the wire.

Prompt Safety Guardrails

Protect your sender reputation. Automatically filter out prompt injections, spam patterns, and unverified links generated in real-time by LLM pipelines.

Agent-to-Human Feedback

Bidirectional communications. Receive, parse, and feed incoming human email replies directly back to your agents via clean webhooks and callback systems.

Built for Agent SDKs

Integrate using standard HTTP clients and tool-use patterns. Any agent framework that can call REST endpoints can send mail through Piisend.

Secure Sandbox Execution

Test your agents in complete safety. Our live developer sandbox lets you simulate sending and inspect payloads without spending quota or routing actual outbound mail to active test mailboxes.

Integrate via HTTP

Register Piisend as a tool in your agent runtime. Function-calling, custom tools, or plain fetch—if it speaks HTTP, it can send email.

LangChainCrewAILangGraphAutoGenFunction Calling
Read the quickstart
await fetch('https://api.piisend.com/api/v1/emails', {
  method: 'POST',
  headers: { Authorization: 'Bearer …' },
  body: JSON.stringify({ to, subject, html }),
});

Ready to build

Ship your first email today

Create an API key, send a test message, and wire webhooks in under ten minutes.