> ## Documentation Index
> Fetch the complete documentation index at: https://ahasend.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
> ## Agent Instructions
> AhaSend stores all message data in the EU. See /facts.
> The API base URL is https://api.ahasend.com. Send the API key in the Authorization: Bearer header. See /api-reference/authentication.
> Use send.ahasend.com for SMTP in the EU, or send-us.ahasend.com as a US connection point forwarding to the EU. Ports 25, 587 and 2525 use STARTTLS. Port 465 is not supported. See /smtp.
> For send-only integrations, create an API Key v2 under Credentials → Add and scope it to messages:send:{your-domain}. See /send-api/credentials and /api-reference/scopes.
# Create an API Key for Sending Email
> Create an AhaSend API v2 key, choose production or sandbox mode, restrict it to specific domains, and authenticate email API requests with a Bearer token.
AhaSend send-only API keys let your application send email from selected domains; this guide shows how to create and manage those keys.
Available on Free, Pro and Max. See [plans and features](/docs/facts#plans-and-features).
API v1 is in maintenance mode. Use v2 for new integrations; see [API v1 vs v2](/docs/api-reference/v1/v1-vs-v2).
AhaSend send-only API keys let your application send email through API v2. Create them at **Credentials → Add → API Key v2**. They use the `aha-sk-` prefix followed by 64 characters, and authenticate with a Bearer header.
Choose a verified sending domain for the `messages:send:{your-domain}` scope. For sending from many domains, a global send-only key uses `messages:send:all`. These keys do not grant management access. For domains, webhooks, routes, suppressions, reports or the CLI, create a full key under **Account Settings → API Keys** with the needed [scopes](/docs/api-reference/scopes); see [authentication](/docs/api-reference/authentication).
## Creating API Keys
1. **Log in** to your [AhaSend Dashboard](https://dash.ahasend.com)
2. **Navigate** to the **[Credentials](https://dash.ahasend.com/account/-/transactional/credentials)** section from the main menu
3. **Click** the **"Add"** button
**Select Credential Type:**
* Choose **"API Key v2"** as the credential type for advanced features
**Choose a Descriptive Name:**
* Use a name that helps you identify this API key later
* Examples: "Production API v2", "example.com API v2", "Marketing Platform v2"
**Naming Tip:** If you have multiple domains or applications, include descriptive information in your API key name (e.g., "example.com Production API v2", "Newsletter Service v2") to make management easier.
Choose the appropriate mode for your use case:
**Production Mode:**
* Sends emails to real recipients
* Use for live applications and real email delivery
* Emails are delivered normally
**Sandbox Mode:**
* Simulates email sending without actual delivery to recipients
* Perfect for testing and development environments
* Completely free - doesn't count toward your email credits
* Still triggers webhooks for testing your integrations
**Sandbox Benefits:** Sandbox mode processes emails just like production (including webhook events) but stops short of actual delivery. This makes it perfect for testing your integration safely. [Learn more about sandbox mode →](/docs/send-api/sandbox)
**Global Scope:**
* Works with all domains in your account
* Use when sending from many domains
* Can be changed later if needed
**Domain-Specific Scope:**
* Restricts API key to specific domains
* Better security for multi-domain setups
* Requires separate API keys per domain
1. **Click** "Create Credential" to generate your API key
2. **Copy and securely store** the API key
3. **Save it** in your password manager or secure storage
### API Key Scoping
* Works with all domains in your account
* Uses `messages:send:all` for sending from many domains
* Prefer a domain-specific key when your app sends from one domain
* Sending only; no management access
* Restricts sending to `messages:send:{your-domain}`
* Better security for multi-domain setups
* Prevents accidental cross-domain sending
* Ideal for client-specific applications
### Account ID and First Request
Find your account ID in the dashboard's account settings. Replace `YOUR_ACCOUNT_ID`, `YOUR_API_KEY`, and `hello@yourdomain.com` with your account, key, and verified sender.
```bash theme={null}
curl --request POST 'https://api.ahasend.com/v2/accounts/YOUR_ACCOUNT_ID/messages' \
--header 'Authorization: Bearer YOUR_API_KEY' \
--header 'Content-Type: application/json' \
--data '{"from":{"email":"hello@yourdomain.com"},"recipients":[{"email":"test@example.com"}],"subject":"API key test","text_content":"Hello from AhaSend","sandbox":true}'
```
See [sending email](/docs/send-api/send-email), the [Node.js SDK](/docs/guides/nodejs-sdk), and the [Go SDK](/docs/guides/go-sdk).
### Integration Examples
Please see [CreateMessage API Reference](/docs/api-reference/messages/create-message) for code samples of sending emails using the API.
## Related Guides
* [Domain setup](/docs/domains), [API authentication](/docs/api-reference/authentication), [Create Message reference](/docs/api-reference/messages/create-message).
* [SMTP settings](/docs/smtp), [CLI sending](/docs/cli/commands/messages), [Node.js SDK](/docs/guides/nodejs-sdk).
* [Go SDK](/docs/guides/go-sdk), [Sandbox mode](/docs/send-api/sandbox), [CLI webhook testing](/docs/cli/webhook-testing).
* [Permission scopes](/docs/api-reference/scopes), [Idempotency](/docs/api-reference/idempotency), [API errors](/docs/api-reference/errors).
* [Rate limits](/docs/api-reference/rate-limits), [Suppression durations](/docs/bounces#suppression-duration).
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