Official vendor OpenAPI document · agent-readyCommunicationsEmail Deliverybearer69 EndpointsREST
For Agents
Programmatically send an email, retrieve a list of emails. Covers 69 operations with bearer authentication.
Use for: I need to send an email, I want to a list of emails, Search for a single email, Find all a single email
Not supported: Does not handle payments, crm, or developer tools - use for communications only.
Resend is the email platform for developers. The API exposes 69 endpoints secured with bearer authentication.
Install Jentic One Beta
Connect the Resend to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Resend, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fresend.com%2Fresend" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fresend.com%2Fresend" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Resend API.
Send an email
Retrieve a list of emails
Update a single email
Cancel the schedule of the e-mail.
Trigger up to 100 batch emails at once.
Use Cases
Patterns agents use Resend API for, with concrete tasks.
★ Communications Operations
Use the Resend to perform communications operations programmatically. The API provides 69 endpoints covering core functionality including send an email, retrieve a list of emails, retrieve a single email.
Call POST /emails to send an email
Automated Emails Management
Automate emails operations by combining multiple Resend endpoints. Agents can retrieve a list of emails and then retrieve a single email in a single workflow.
Call GET /emails to retrieve a list of emails, then verify the result
AI Agent Integration via Jentic
AI agents discover and call Resend endpoints through Jentic without managing credentials directly. An agent searches for the required operation by intent, receives the matching endpoint schema, and executes the call with Jentic-managed authentication. This eliminates the need to read API documentation or handle bearer tokens manually.
Search Jentic for 'send an email', load the operation schema, and execute with Jentic-managed credentials
Key Endpoints
69 endpoints — resend is the email platform for developers.
METHOD
PATH
DESCRIPTION
POST
/emails
Send an email
GET
/emails
Retrieve a list of emails
GET
/emails/{email_id}
Retrieve a single email
PATCH
/emails/{email_id}
Update a single email
POST
/emails/{email_id}/cancel
Cancel the schedule of the e-mail.
POST
/emails/batch
Trigger up to 100 batch emails at once.
GET
/emails/{email_id}/attachments
Retrieve a list of attachments for a sent email
GET
/emails/{email_id}/attachments/{attachment_id}
Retrieve a single attachment for a sent email
POST
/emails
Send an email
GET
/emails
Retrieve a list of emails
GET
/emails/{email_id}
Retrieve a single email
PATCH
/emails/{email_id}
Update a single email
POST
/emails/{email_id}/cancel
Cancel the schedule of the e-mail.
POST
/emails/batch
Trigger up to 100 batch emails at once.
GET
/emails/{email_id}/attachments
Retrieve a list of attachments for a sent email
GET
/emails/{email_id}/attachments/{attachment_id}
Retrieve a single attachment for a sent email
Jentic AI Readiness Score
This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.
R
Resend
- Foundational (C)55/100
79
Foundational Compliance63
Developer Experience & Jentic Compatibility32
AI-Readiness & Agent Experience91
Agent Usability60
Security63
AI DiscoverabilityPowered by JenticScoring Framework 1.0.0 | Scoring Engine 0.4.0
Show dimension breakdown
79
Foundational Compliance
Base layer of spec validity and structural soundness.
Grade: A-Signals: 4
96%
Lint Results
Aggregated quality score from linter diagnostics, weighted by severity.
100%
Resolution Completeness
Percentage of `$ref` references that resolve successfully.
100%
Specification Validity
Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).
21%
Structural Integrity
Structural correctness score based on schema issues using logarithmic dampening.
63
Developer Experience & Jentic Compatibility
Clarity, completeness, and ingestion readiness for developers and tooling.
Grade: B-Signals: 4
26%
Example Density
How richly the API is illustrated with examples.
100%
Example Validity
Percentage of examples that conform to their schemas.
25%
Response Coverage
Percentage of operations with complete response definitions (success, client error, server error).
100%
Tooling Readiness
Health of API ingestion, bundling, and resolution within Jentic pipelines.
32
AI-Readiness & Agent Experience
Semantic breadth, depth, and agent comprehension for AI systems.
Grade: FSignals: 4
63%
Description Coverage
Coverage of descriptions across API elements.
0%
Error Standardization
Coverage of RFC 9457 Problem Details for error responses.
0%
OperationId Quality
Coverage, uniqueness, and casing consistency of operationIds for AI inference.
64%
Summary Coverage
Coverage of summaries across operations/tags/info.
91
Agent Usability
Functional utility, complexity comfort, and AI orchestration readiness.
Grade: A+Signals: 1
91%
Complexity Comfort
Agent comfort level based on API operational and structural complexity.
60
Security
Trust, risk posture, and security compliance.
Grade: B-Signals: 1
60%
Authentication Strength
Average quality of security schemes based on authentication method strength (weakest link for OAuth2).
63
AI Discoverability
Findability, semantic richness, and reasoning readiness.
Grade: B-Signals: 1
62%
Descriptive Richness
Clarity and depth of descriptions across API elements.
Score it yourself
Every API in the directory is allowlisted, so you can re-score it with no key required.
npx @jentic/api-scorecard-cli score <openapi-url>Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring Resend by hand means setting its bearer auth on every request, tracking email ids across send, read, update, and cancel calls, and handling batch and attachment endpoints yourself. Through Jentic you install once, import Resend from the API Directory, store the token once, and your agent calls it.
Permission scoping
Resend puts the email id in the URL path (/emails/{email_id}), so a rule can pin your agent to reading and updating a specific email. You choose the operations it may call, so a state-changing one like cancelling a scheduled email is not included unless you add it.
Credential isolation
Your Resend token is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'send an email' or 'cancel a scheduled email', and Jentic returns the matching Resend operation with its input schema so the agent calls the right endpoint without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Resend API through Jentic.
What authentication does the Resend use?
The Resend uses a Bearer token in the Authorization header. Through Jentic, these credentials are stored encrypted in your Jentic One instance and injected at execution time, so raw secrets never enter the agent context.
Can I send an email with the Resend?
Yes. Use the POST /emails endpoint. The API returns structured JSON responses that agents can parse and act on directly.
What are the rate limits for the Resend?
Rate limits are not specified in the OpenAPI spec. Check the vendor documentation for current limits. Through Jentic, rate limiting is handled automatically with retry logic built into the execution layer.
How do I send an email through Jentic?
Install the Jentic SDK with pip install jentic, authenticate through Jentic One, the self-hosted execution layer, then search for 'send an email'. Jentic returns the matching Resend operation with its input schema. Load the schema and execute the call - credentials are injected automatically.
How many endpoints does the Resend have?
The Resend exposes 69 endpoints covering emails, domains, API keys operations.
Can I limit what my agent is allowed to do with the Resend API?
Yes. Because you run Jentic One yourself, your own rules decide which Resend operations and credentials the agent may use. You can grant it just the calls you want, such as POST /emails to send or GET /emails to read, while leaving out state-changing ones like cancelling a scheduled email at /emails/{email_id}/cancel. Since Resend puts the email id in the URL path, a rule can also pin the agent to reading or updating one specific email rather than every message on the account.
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