resend

library2.41.0pypypi✓ verified 28d ago

Official Python SDK for the Resend transactional email API. Active, frequently updated. v2.0 (May 2024) added TypedDict-based type hinting. Module-level api_key pattern is the primary auth method. No class instantiation — all methods are called as class methods on resend.Emails, resend.Contacts, etc.

communication

pip install resend

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · RESEND

resend

communicationpythonv2.41.0

Install

2.3s avg

Import

455ms

Disk

21MB

Pass rate

10/ 10

Env Coverage10 / 10

glibc

3.9–3.13

musl

3.9–3.13

Install & Compatibility

Where this runs

tested against v2.41.0 · pip install

no network on importno background threads

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

py 3.10–3.95 runs

installs and imports cleanly · install 0.0s · import 0.482s · 22.7MB

glibc

py 3.10–3.95 runs

installs and imports cleanly · install 2.3s · import 0.428s · 23MB

21MB installed

● package 21MB

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

ApiKey

✓ from resend import ApiKey

✗ import resend

'from' field must use a verified domain. Use 'onboarding@resend.dev' only for testing. The 'to' field must be a list even for single recipients.

import os import resend resend.api_key = os.environ['RESEND_API_KEY'] params: resend.Emails.SendParams = { 'from': 'Acme <onboarding@resend.dev>', 'to': ['delivered@resend.dev'], 'subject': 'Hello from Resend', 'html': '<strong>It works!</strong>' } email = resend.Emails.send(params) print(email['id']) # e.g. '49a3999c-0ce1-4ea6-ab68-b08b6e9a5fe2'

Debug

Known issues

gotchaNo client class to instantiate — resend.api_key is set at the module level, then all API calls are made as class methods (resend.Emails.send(), resend.Contacts.list(), etc.). Code from other SDKs that tries to instantiate a client object fails.

fix

import resend; resend.api_key = 'YOUR_KEY'; resend.Emails.send(params)

affects: all

gotchaThe 'to' field must always be a list, even for a single recipient. Passing a string raises a validation error.

fix

'to': ['user@example.com']  # not 'to': 'user@example.com'

affects: all

gotchaThe 'from' field must use a domain verified in the Resend dashboard. Using unverified domains or personal email addresses returns 403. The address 'onboarding@resend.dev' works only in testing with the test API key.

fix

Verify your domain at resend.com/domains before sending. Format: 'Name <email@yourdomain.com>'

affects: all

gotchaModule-level api_key is global state — in multi-tenant or async applications with different API keys, setting resend.api_key is not thread-safe. Concurrent requests may use the wrong key.

fix

For multi-key scenarios, serialize key setting + API call, or use separate processes/containers per API key.

affects: all

gotchaPip warnings detected in the test output, indicating 'Running pip as root' which can cause permission issues, and an 'outdated pip version'. These are environment-specific warnings during package management, not direct failures related to the resend library's functionality.

fix

It is recommended to use a virtual environment for pip operations (e.g., `python -m venv .venv && source .venv/bin/activate`) and to keep pip updated (`pip install --upgrade pip`).

affects: all

Upgrade

Version history

2.41.0latest on PyPI · released Aug 26, 2026

Audit

Dependencies

No dependency data recorded yet.

Agent activity

27 hits · last 30 days

node

Amazon

OpenAI (training)

Resources

githubhttps://github.com/resendlabs/resend-python ↗

packagehttps://pypi.org/project/resend/ ↗

homepagehttps://resend.com ↗