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Eleidon

Eleidon is an email identity layer for AI agents that verifies inbound messages before action and lets recipients verify outbound messages. It provides signing and verification tools for developers through SDKs, an MCP server, and a CLI.

Eleidon

Overview

Eleidon is an email identity layer for AI agents. It is designed to help agents verify whether an inbound email is authentic before taking action, and to let humans or other systems confirm that an outbound email was actually signed by the agent that sent it.

The product centers on a simple cryptographic workflow: register an agent, sign outgoing messages, and allow anyone to verify them. The site positions this as a way to reduce spoofing risk, add message integrity checks, and provide clearer evidence when email-driven automation is disputed.

Core capabilities

Agent registration

Register an agent by generating a keypair and associating the public key with a claimed inbox.

Outbound signing

Attach a cryptographic signature to outbound email so recipients can verify the message really came from the agent.

Inbound verification

Check inbound emails through a verification endpoint that returns a result and confidence score.

Verification for recipients

Use the service without requiring an API key for verification requests, according to the product flow shown on the home page.

Multiple developer interfaces

Work from the provided SDKs and command-line tools, including TypeScript, Python, MCP, and CLI options.

Structured verification response

Inspect verification output that includes identity and integrity fields such as agent ID, claimed inbox, inbox verification, and signature ID.

Practical use cases

  • Inbound instruction checks

    Use Eleidon when an agent receives an instruction email and needs a way to check whether the sender is actually authorized before acting on it.

  • Outbound authenticity

    Use the signing flow for agent-generated confirmations, status updates, or support replies so recipients can verify the message origin.

  • Automated verification

    Use the verification endpoint in services that need a machine-readable answer with identity and confidence fields instead of a manual review step.

  • Developer integration

    Use the SDKs or CLI when you want to add signing and verification to application code, a model-using workflow, or terminal-based operations.

Pros and Cons

Pros

  • Covers both inbound verification and outbound signing in one workflow.
  • Offers a verification endpoint that recipients can use without an API key, based on the site’s flow description.
  • Provides multiple implementation paths with SDKs, an MCP server, and a CLI.
  • Shows structured verification results rather than a vague pass/fail outcome.
  • Signing is described as free and unlimited on the home page.

Cons

  • The pricing page itself is unavailable, so plan details beyond the home page pricing section are limited.
  • The site does not publish integrations, compliance certifications, or an enterprise security page in the provided sources.
  • Verification is metered by plan, so heavy inbound checking may require a paid tier.

FAQ

What does Eleidon do?

Eleidon verifies inbound emails before an agent acts on them and lets recipients verify outbound messages signed by the agent. The site describes a workflow where anyone can verify a message through the verification endpoint without needing an API key.

How does setup work?

The site presents three steps: generate a keypair and register the agent, sign outgoing email with the private key, and let recipients verify the signature through the verification endpoint.

What ways can teams use Eleidon?

The home page lists SDKs for TypeScript and Python, plus an MCP server and a CLI. It also shows a direct API flow for verification.

Is signing and verification priced the same way?

No. The pricing section says signing is free and unlimited, while verification is metered by plan. It also shows a free tier, paid plans, and a contact-us option for enterprise.

What does Eleidon return when a message is checked?

The source shows message verification returning a confidence score and fields such as agent ID, claimed inbox, inbox verification, and signature ID. It does not describe formal compliance certifications or guarantees.

Quick Facts

Category
Developer Tool
Primary use
Trusted email for AI agents
Main workflow
Register agent, sign emails, verify messages
Developer interfaces
TypeScript SDK, Python SDK, MCP server, CLI
Source domain
eleidon.com
Pricing note
Signing is free and unlimited; verification is metered by plan