resend

name

resend

description

Resend is a platform for building, testing, and sending transactional emails programmatically. It helps developers integrate and monitor email delivery at scale with ease. Read and write Resend data through One: emails, templates, contacts, broadcasts, domains, contactproperties and more, 67 actions with real parameter documentation. Use whenever the user asks to look something up in Resend, create or update a record there, or build code against the Resend API.

Resend through One

Resend is a platform for building, testing, and sending transactional emails programmatically. It helps developers integrate and monitor email delivery at scale with ease.

One exposes Resend through four MCP tools. The table below carries real action ids from One's knowledge base, so for a common operation you can skip search and go straight to reading the action's parameters.

How to run an action

1. Find the action in the table below, or call search_one_platform_actions with platform resend if it is not listed.
2. Call get_one_action_knowledge with the action id. Do this every time, including for actions in this table. The table gives you the id, not the parameters.
3. Call execute_one_action with parameters copied from that knowledge.

Never guess a parameter name, a body field, or an enum value. The knowledge has the real schema, and a guessed field is either a 400 or a silent write of the wrong thing.

Before you start

Call list_one_integrations once and confirm Resend is connected. If it is missing, the user has not connected it: say so and point them at https://app.withone.ai rather than reaching for raw HTTP.

Each connection carries an access field. If it reports {"policy": "methods", "methods": ["GET"]} the agent is read-only here, so plan a read-only answer instead of attempting a write that will be refused.

Before a write

Creates, updates, deletes and sends land on a real Resend account and cannot be recalled. State the action and the specific target in one line before the first write in a task, and let the user stop you. Reads need no confirmation.

Actions

Emails

Action	Method	Path	Action id
List a Sent Email’s Attachments	GET	/emails/{{emailId}}/attachments	conn_mod_def::GJ6SReEHPcE::f1Q9958PTai145ogEOJ0Wg
List Emails	GET	/emails	conn_mod_def::GJ6SRf8FQWg::MmeqceRoTmSeLYCxbaAmUA
Retrieve a Single Email	GET	/emails/{{emailId}}	conn_mod_def::GJ6SRcerbx4::hFG382R8SteemlQRBdYvtQ
Cancel a Scheduled Email	POST	/emails/{{emailId}}/cancel	conn_mod_def::GJ6SRU_IODQ::uZ-yJz-jSPKdMSPWhlI2KA
Send an Email	POST	/emails	conn_mod_def::GJ6SRgloL9U::ffk4sD2zRU-J_jTGGdBk5w
Send Batch Emails	POST	/emails/batch	conn_mod_def::GJ6SRoHZm8Q::cVupy9ZORNmCasMiTRsJlg
Update an Email	PATCH	/emails/{{emailId}}	conn_mod_def::GJ6SRnxxnKo::vyJ_Tm94Q1Gjcv44rP0Cig

Templates

Action	Method	Path	Action id
List Templates	GET	/templates	conn_mod_def::GJ6SR9sumbc::BuAgBQSNTGGPrWPVu3JtNQ
Retrieve a Template	GET	/templates/{{id}}	conn_mod_def::GJ6SSKFbhCI::vMg7ZSpRQkysU38sf3uzIQ
Create a Template	POST	/templates	conn_mod_def::GJ6SR9X5u0w::KBsye0N7QgybB-u4xrpSTA
Delete a Template	DELETE	/templates/{{id}}	conn_mod_def::GJ6SR9I1k6Y::23njFYTfRjabj6776PqFeA
Duplicate a Template	POST	/templates/{{id}}/duplicate	conn_mod_def::GJ6SSAX30Io::KxA0MGP8QWSCNRORgmlvvQ
Publish a Template	POST	/templates/{{id}}/publish	conn_mod_def::GJ6SSC-PjSw::7OsF06T0QIarFuUXRgUSWA
Update a Template	PATCH	/templates/{{id}}	conn_mod_def::GJ6SSKovHx4::FT0F0lo_SZ6RGQTZ2kWZUQ

Contacts

Action	Method	Path	Action id
List Contacts	GET	/contacts	conn_mod_def::GJ6SQ7DFu44::Ndbs37cHSEKvas_wTgG2mw
Retrieve a Contact by ID or Email	GET	/contacts/{{id}}	conn_mod_def::GJ6SQ5s1QZo::faJisv9DTHGzq_A19Zs8vA
Create a Contact	POST	/contacts	conn_mod_def::GJ6SQt3jhlI::10Leh5p5RR2V7V673_r8oA
Delete a Contact	DELETE	/contacts/{{id}}	conn_mod_def::GJ6SQ6V8mMg::loR3evzrR-mCP4w9ybLO6A
Update a Contact by ID or Email	PATCH	/contacts/{{id}}	conn_mod_def::GJ6SRDQbg5k::hBgqy1SUTkGdj_S9aWBi8A
Update a Contact’s Topics	PATCH	/contacts/{{contactId}}/topics	conn_mod_def::GJ6SRJ1ZBCk::NmI04M2QQmiDdUMeGw7A2w

Broadcasts

Action	Method	Path	Action id
List Broadcasts	GET	/broadcasts	conn_mod_def::GJ6SQX9Jyh0::U-CTSzAvSzKuD25Q3TIK4Q
Retrieve a Broadcast	GET	/broadcasts/{{id}}	conn_mod_def::GJ6SQgVHZXg::izwXC941TfS_CNMqtrvpIA
Create a Broadcast	POST	/broadcasts	conn_mod_def::GJ6SQU-Yehs::sMxrd3AZSQOkWwwaHLU46g
Delete a Broadcast Draft	DELETE	/broadcasts/{{id}}	conn_mod_def::GJ6SQTtCmwc::SCII7IsVS5Wio4qQdPZ0oQ
Send or Schedule a Broadcast	POST	/broadcasts/{{id}}/send	conn_mod_def::GJ6SQf1CnvU::qYu8Ko0jRviqSVgIrsR9Wg
Update a Broadcast	PATCH	/broadcasts/{{id}}	conn_mod_def::GJ6SQmzVh5g::0CmkH8JwR4ip11kQL-2fEw

Domains

Action	Method	Path	Action id
List Domains	GET	/domains	conn_mod_def::GJ6SRTe7Fh8::tB_m8RIIRnSHLTTKV_-E2w
Retrieve a Domain	GET	/domains/{{domainId}}	conn_mod_def::GJ6SRSBtDLM::uOwpomkXQ9qZX1M7nlJ01g
Create a Domain	POST	/domains	conn_mod_def::GJ6SRDxtYJs::ooMtDHuoRUGsXRRmENF3IQ
Remove a Domain	DELETE	/domains/{{domainId}}	conn_mod_def::GJ6SRCly_Dg::WDYeJu9RT3ilFQja73FVxA
Update a Domain	PATCH	/domains/{{domainId}}	conn_mod_def::GJ6SRRrKowA::2ARJbS8PQdOXDgjG10dGyg
Verify a Domain	POST	/domains/{{domainId}}/verify	conn_mod_def::GJ6SRUbooAM::NCip1IyKRfiKuJQzwE2B4A

ContactProperties

Action	Method	Path	Action id
List Contact Properties	GET	/contact-properties	conn_mod_def::GJ6SQvvhIhQ::BPzfBHSiQQGcpjLz-m5UtA
Retrieve a Contact Property	GET	/contact-properties/{{id}}	conn_mod_def::GJ6SQvW0Qps::sSgFPHr1Qgq-HRp_I6I46Q
Create a Contact Property	POST	/contact-properties	conn_mod_def::GJ6SQlTaP64::Ua2wW9ShQhy8f94Af_XdkA
Delete a Contact Property	DELETE	/contact-properties/{{id}}	conn_mod_def::GJ6SQfeZeys::Q5dycmGTT8W0kdZjc9hx-A
Update a Contact Property	PATCH	/contact-properties/{{id}}	conn_mod_def::GJ6SQyOMWBc::L2m7Yfo7TSSYXC4rfgLjZA

Topics

Action	Method	Path	Action id
List Topics	GET	/topics	conn_mod_def::GJ6SSKwhyis::qPHbHCC3TNO0DsmvIXWegA
Retrieve a Topic	GET	/topics/{{id}}	conn_mod_def::GJ6SSSdIGc8::Ax9LaEQ8SJe4QCPNyq9OBg
Create a Topic	POST	/topics	conn_mod_def::GJ6SSKnUG08::vSVjmpJlQRymCrQEcNiLHg
Delete a Topic	DELETE	/topics/{{id}}	conn_mod_def::GJ6SSJ7V0pU::05L95JI6RIaex4XJdxq5jQ
Update a Topic	PATCH	/topics/{{id}}	conn_mod_def::GJ6SSWg8Z8Q::-BqCdu1USTuSmaDeMN8T1g

Webhooks

Action	Method	Path	Action id
List Webhooks	GET	/webhooks	conn_mod_def::GJ6SSTwQGjk::Lb29VMQaSHqKbU6ZZjdINw
Retrieve a Webhook	GET	/webhooks/{{webhookId}}	conn_mod_def::GJ6SSfoVFJg::CbYmUEs4RXe87u3fXcI-0g
Create a Webhook	POST	/webhooks	conn_mod_def::GJ6SSSj-VGk::18at33nmRQiQhaT7OxoPXQ
Delete a Webhook	DELETE	/webhooks/{{webhookId}}	conn_mod_def::GJ6SSXL1wH8::Q-IpinknT7CiKabqtHTG9A
Update a Webhook	PATCH	/webhooks/{{webhookId}}	conn_mod_def::GJ6SSjJ3Tbg::ivzeVeNyRyuD6MQv6vFsGw

Audiences

Action	Method	Path	Action id
List Audiences	GET	/audiences	conn_mod_def::GJ6SQUIMvzY::0051QQElRzC6L2BC79U8jw
Retrieve a Single Audience	GET	/audiences/{{id}}	conn_mod_def::GJ6SQT8WK3Q::1ItNW3inSjq0VAobYCXVGg
Create an Audience (Contact List)	POST	/audiences	conn_mod_def::GJ6SQMMS_l0::paFbnLH8Rp6ThJHA8KQf2A
Remove an Audience	DELETE	/audiences/{{id}}	conn_mod_def::GJ6SQJ9h_2w::j7nUO2i9SlKc8u0MGZLnkQ

Segments

Action	Method	Path	Action id
List Segments	GET	/segments	conn_mod_def::GJ6SR1Wx3bs::mVb7qoy0Tdexa4ecFQpXGQ
Retrieve a Segment	GET	/segments/{{id}}	conn_mod_def::GJ6SR1dOqTc::HETT_IzIT8-Ctc1PbUVDaw
Create a Segment	POST	/segments	conn_mod_def::GJ6SR0vqLuY::iUGMTEnKS7-7exuUV-JB6Q
Delete a Segment	DELETE	/segments/{{id}}	conn_mod_def::GJ6SR0y9eV4::eKxoccOqQoKJztiSwc25oA

ApiKeys

Action	Method	Path	Action id
List API Keys	GET	/api-keys	conn_mod_def::GJ6SQK6lvm8::trDTdSJeTeK1WKxhOkrLGQ
Create an API Key	POST	/api-keys	conn_mod_def::GJ6SQIayOl8::dwrNtslSTduCzlsGg_3bKg
Remove an API Key	DELETE	/api-keys/{{apiKeyId}}	conn_mod_def::GJ6SQIU-98U::Uu_tg_ERRTqQl_gK_jivsw

ContactSegments

Action	Method	Path	Action id
Add a Contact to a Segment	POST	/contacts/{{contactId}}/segments/{{segmentId}}	conn_mod_def::GJ6SQuYl700::04X1vCBfR8WTQ15gP2ssXQ
Remove a Contact from a Segment	DELETE	/contacts/{{contactId}}/segments/{{segmentId}}	conn_mod_def::GJ6SQ6Mv3Po::80Sh4zV6QEe1pMSRRsjyvQ

ReceivedEmailAttachments

Action	Method	Path	Action id
List Attachments for a Received Email	GET	/emails/receiving/{{emailId}}/attachments	conn_mod_def::GJ6SRqyQ5II::0whWu-NjTRaNHVzSa0tJNw
Retrieve a Received Email Attachment	GET	/emails/receiving/{{emailId}}/attachments/{{attachmentId}}	conn_mod_def::GJ6SRohm7Kw::C1UB6v8MTtudwvCblNHswQ

ReceivedEmails

Action	Method	Path	Action id
List Received Emails	GET	/emails/receiving	conn_mod_def::GJ6SRt19kWs::cnNGF5y-QeOFXG-WqAZnQg
Retrieve a Received Email	GET	/emails/receiving/{{emailId}}	conn_mod_def::GJ6SR1smyYk::jcWNj6MARdmjFJbPM10Biw

ContactsTopics

Action	Method	Path	Action id
List a Contact’s Topics	GET	/contacts/{{contactId}}/topics	conn_mod_def::GJ6SRFeDA2g::tNICtRvLRpGnjZJShCAYAw

EmailsAttachments

Action	Method	Path	Action id
Retrieve an Email’s Attachment	GET	/emails/{{emailId}}/attachments/{{attachmentId}}	conn_mod_def::GJ6SRfcBtYo::5N4OabrmSuqPqDqOmneDSw

ContactsSegments

Action	Method	Path	Action id
List a Contact’s Segments	GET	/contacts/{{contactId}}/segments	conn_mod_def::GJ6SQ6eEMoc::ENFPxMD9R-2cK93bcc7rDA

When a call fails

The error comes from Resend, not from One. A 400 or 422 means your parameters do not match the schema, so re-read the knowledge and fix the field. A 401 or 403 means the connection needs re-authorizing, which no retry will fix. A 404 means the id is not on this account. A 429 means slow down. Never retry a write more than once: the first attempt may have landed.

Full catalog: https://www.withone.ai/knowledge/resend

Integration knowledge by One (withone.ai), licensed under One-Knowledge-1.0. Attribution must be preserved in derivative works.