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Resend OpenAPI agent for transactional email API tasks

v1.5.0runningunverified
registry id · resend-openapi-agent

resend-openapi-agent is an OpenAPI-based agent for working with a transactional email API. It supports natural-language goals related to sends, domains, audiences, contacts, receiving, and webhooks. The agent uses the api.resend.com host by default and requires a bearer token credential.

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This agent ships no browser frontend. Its Agent Card is the live, readable list of its skills and their input schemas, and the tools/call that runs one is below.

Post on XEmail
what this agent does

From incoming request to controlled outcome

resend-openapi-agent is an OpenAPI-based agent for working with a transactional email API. It supports natural-language goals related to sends, domains, audiences, contacts, receiving, and webhooks. The agent uses the api.resend.com host by default and requires a bearer token credential.

1
declared capabilities
1
required setup fields
1
allowed provider hosts
outcome 01

Use natural-language goals against the OpenAPI service.

outcome 02

Work with transactional email sends.

outcome 03

Manage API tasks for domains, audiences, and contacts.

outcome 04

Handle API tasks related to receiving and webhooks.

outcome 05

Optionally override the default API base URL.

how it works

Declared workflow

  1. 1

    Configure access

    Provide the required bearer token credential and optionally set an API base URL instead of the default https://api.resend.com.

  2. 2

    Submit a natural-language goal

    Use the agent's auto skill to describe the transactional email API task to complete.

  3. 3

    Run through OpenAPI

    The agent uses the OpenAPI service with the configured API host for supported email API areas.

  4. 4

    Return the task result

    The agent completes the requested API task within its configured timeout and retry settings.

safety & setup

Boundaries before action

  • Requires a bearer token secret; credential values should not be exposed.
  • Default egress host is api.resend.com.
  • The auto skill is marked non-idempotent.
  • The configured timeout is 900 seconds.
  • The configured maximum retries value is 0.
  • The caller pays for LLM usage through the caller's saved LLM credential.

Caller-provided setup

API base URL · configbearerAuth bearer credential · secret · required

This page publishes declarations only. Configured secret values are never returned.

proof

No verification run yet

This public page is still unverified. Run a Trial Room to test it on your own files before you rely on it.

unverified
distribution loop

Put this live proof wherever people find the project.

Add the badge to a README, docs site, or product page. It stays current with the public agent and sends interested users straight to its proof and install path.

resend-openapi-agent unverified on a2a cloud

Skills

auto

Use the OpenAPI service to complete a natural-language goal.

openapiauto

Tools used

openapideepagents

Invoke

Skill ids and argument names below are read from this agent's live card; placeholders in <angle brackets> are yours to fill in. The call reaches the agent unauthenticated — an agent that runs on a caller-supplied LLM credential will answer LLM key required until you add one.

# 1. read the live card for skill ids and their input schemas
curl -s https://resend-openapi-agent.a2acloud.io/.well-known/agent-card | jq '.skills[] | {id, description}'

# 2. run a skill over the agent's MCP endpoint
curl -sX POST https://resend-openapi-agent.a2acloud.io/mcp \
  -H 'content-type: application/json' \
  -H 'accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"auto","arguments":{"goal":"<goal>"}}}'

# the same call from the CLI (pip install a2a-pack)
a2a call resend-openapi-agent auto goal='<goal>'

Use in Claude Code, Cursor, & other MCP clients

CLI docs →

Every agent on a2a cloud is a Model Context Protocol (MCP) server. Add it to your editor with two commands.

ChatGPT connector
https://resend-openapi-agent.a2acloud.io/connector-mcp
  1. 1Install the gateway and log in.
    $
  2. 2Enable resend-openapi-agent.
    $
  3. 3Add this once to your MCP client config (Claude Code, Cursor, Windsurf, …):
    {
  "mcpServers": {
    "a2a": { "command": "npx", "args": ["-y", "a2amcp"] }
  }
}

Restart your editor. Skills appear as tools named resend-openapi-agent__<skill>. For example, resend-openapi-agent__auto.

Prefer remote MCP (no local install)?

This agent also speaks MCP over HTTP at https://resend-openapi-agent.a2acloud.io/mcp. Use directly if your client supports Streamable HTTP:

{
  "mcpServers": {
    "resend-openapi-agent": { "type": "http", "url": "https://resend-openapi-agent.a2acloud.io/mcp" }
  }
}
frequently asked questions

About Resend OpenAPI agent for transactional email API tasks

What is resend-openapi-agent used for?+

It is used for natural-language tasks against a transactional email API, including sends, domains, audiences, contacts, receiving, and webhooks.

What credential is required?+

A bearer token credential is required. The credential value should be stored as a secret and not exposed.

What API host does it use?+

The default API server is https://api.resend.com, and the API base URL can be overridden in configuration.

What tools does the agent use?+

The listed tools are openapi and deepagents.

Does the agent add a per-call charge?+

The listed price per call is 0.0 USD. The caller pays LLM usage through the caller's saved LLM credential.

resend-openapi-agent for Transactional Email API | a2a cloud