> ## Documentation Index > Fetch the complete documentation index at: https://docs.reallyquickemails.com/llms.txt > Use this file to discover all available pages before exploring further. # v1 Public API > Send individual, templated, or batch emails from the v1 API. The ReallyQuickEmails (RQE) v1 public API exposes Bearer-token-authenticated endpoints for external integrations. **Base URL:** `https://api.reallyquickemails.com` *** ## Authentication All endpoints require a Bearer token with a project key: ``` Authorization: Bearer sk_proj_xxxxxxxxxxxx ``` Three key prefixes are accepted: | Prefix | Mode | | ------------- | ----------------------------------- | | `sk_proj_...` | Production (live) | | `sk_live_...` | Production (live) | | `sk_test_...` | [Test mode](/en/concepts/test-mode) | Keys are generated from the project's admin panel. An invalid or missing key responds `401 Unauthorized`. Requests with a body also require the `Content-Type: application/json` header. ### Authentication error response ```json theme={null} { "error": "Missing or invalid API key. Use: Authorization: Bearer sk_proj_..." } ``` If the prefix is valid but does not correspond to any project: ```json theme={null} { "error": "Invalid API key" } ``` *** ## POST /v1/send-email Sends an individual email to up to 50 recipients. ### Request Body | Field | Type | Required | Description | | ----------------- | ------------------- | -------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `recipient_email` | string \| string\[] | Yes | Recipient address(es). Accepts a string (1 recipient) or an array (max 50). For larger volumes use `/v1/send-batch`. | | `sender_email` | string | Yes | Sender address (verified domain). | | `sender_name` | string | No | Sender display name. If omitted, the inbox shows only `sender_email`. | | `html_body` | string | Yes | HTML content of the email. | | `text_body` | string | No | Plain-text version of the email (multipart fallback). Recommended to improve deliverability and accessibility. | | `subject` | string | No | Email subject. If omitted, `"Email from ReallyQuickEmails"` is used. | | `cc` | string \| string\[] | No | Copy address(es). Max 10. | | `bcc` | string \| string\[] | No | Blind-copy address(es). Max 10. | | `attachments` | array | No | List of attachments (max 10; max 10 MB per attachment and 10 MB total). Structure: `{ filename, url \| content (base64), contentType? }`. | | `environment` | string | No | Routes this send's webhooks to the environment configured in the project. Format `[a-zA-Z0-9_.-]`, max 64 characters. If the key is not pre-configured in the dashboard, returns 400 `ENVIRONMENT_NOT_CONFIGURED`. See [Webhook environments](/en/concepts/webhook-environments). | Open and click tracking is applied in the background (transactional senders skip it). This endpoint does **not** add an unsubscribe footer or `List-Unsubscribe` headers — those are added automatically in campaigns and in `/v1/send-template-email`; in `/v1/send-batch` you pass them via `custom_headers`. ### Simple example ```bash theme={null} curl -X POST https://api.reallyquickemails.com/v1/send-email \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" \ -H "Content-Type: application/json" \ -d '{ "recipient_email": "user@example.com", "sender_email": "hello@myapp.com", "sender_name": "My Company", "subject": "Welcome to our platform", "html_body": "

Welcome!

Thanks for signing up.

" }' ``` ```python theme={null} import requests resp = requests.post( "https://api.reallyquickemails.com/v1/send-email", headers={"Authorization": "Bearer sk_proj_xxxxxxxxxxxx"}, json={ "recipient_email": "user@example.com", "sender_email": "hello@myapp.com", "sender_name": "My Company", "subject": "Welcome to our platform", "html_body": "

Welcome!

Thanks for signing up.

", }, ) print(resp.json()) ``` ### Example with multiple recipients + cc + attachment ```bash theme={null} curl -X POST https://api.reallyquickemails.com/v1/send-email \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" \ -H "Content-Type: application/json" \ -d '{ "recipient_email": ["a@company.com", "b@company.com"], "cc": "supervisor@company.com", "sender_email": "notifications@myapp.com", "sender_name": "My Company", "subject": "Daily report", "html_body": "

Report

Attached you will find the details.

", "attachments": [ { "filename": "report.pdf", "url": "https://storage.myapp.com/reports/2026-04-28.pdf", "contentType": "application/pdf" } ] }' ``` ```python theme={null} import requests resp = requests.post( "https://api.reallyquickemails.com/v1/send-email", headers={"Authorization": "Bearer sk_proj_xxxxxxxxxxxx"}, json={ "recipient_email": ["a@company.com", "b@company.com"], "cc": "supervisor@company.com", "sender_email": "notifications@myapp.com", "sender_name": "My Company", "subject": "Daily report", "html_body": "

Report

Attached you will find the details.

", "attachments": [ { "filename": "report.pdf", "url": "https://storage.myapp.com/reports/2026-04-28.pdf", "contentType": "application/pdf", } ], }, ) print(resp.json()) ``` **Response** `200 OK` ```json theme={null} { "message": "Email sent successfully", "email_id": "550e8400-e29b-41d4-a716-446655440000", "project_id": "123e4567-e89b-12d3-a456-426614174000" } ``` `email_id` is the send's activity ID — use it to correlate the events from your [webhooks](/en/api-reference/webhooks). It is `null` if the activity record could not be created. Checked when processing the send in the background. If the recipient is suppressed (bounce, complaint, or unsubscribe), the email is not sent and the activity remains with status `suppressed`. This endpoint does not return a synchronous `skipped` response — `/v1/send-template-email` does check suppression before responding. ### Error Codes | Code | Description | | ----- | ------------------------------------------------------------------------------------------------- | | `400` | `Missing required fields: recipient_email, sender_email, html_body` | | `400` | `recipient_email must be a non-empty string or array of strings` | | `400` | `Too many recipients in recipient_email (N). Maximum is 50. For larger sends use /v1/send-batch.` | | `400` | `cc accepts at most 10 addresses` / `bcc accepts at most 10 addresses` | | `400` | `attachments must be an array` / `attachments accepts at most 10 items` | | `400` | `ENVIRONMENT_NOT_CONFIGURED` — the `environment` is not configured in the project. | | `401` | Invalid or missing API Key. | | `500` | Internal server error. | | `502` | `Failed to process request` — internal error while processing the request. | Need scheduled sending, `dry_run`, or templates on individual sends? See [Advanced send API](/en/api-reference/send-email). *** ## POST /v1/send-template-email Sends an email with a pre-configured template and variable substitution (supports `{{#each}}` loops). ### Request Body | Field | Type | Required | Description | | ---------------------- | ------ | -------- | ------------------------------------------------------------------------------------------------------------------------------- | | `template_id` | string | Yes\* | Template UUID. | | `template_internal_id` | number | Yes\* | Internal template ID (alternative to `template_id`). | | `html_body` | string | Yes\* | Direct HTML content with variables (template-less mode). Required if you send neither `template_id` nor `template_internal_id`. | | `recipient_email` | string | Yes | Recipient email address. | | `sender_email` | string | Yes | Sender email address (verified domain). | | `sender_name` | string | No | Sender display name. | | `subject` | string | No | Email subject. Supports variables. If omitted with a template, the template's subject is used. | | `variables` | object | No | Variables for substitution in the template. | | `environment` | string | No | Same as in `/v1/send-email`: routes webhooks to the configured environment. | \*You must send `template_id` OR `template_internal_id`. If you send neither, `html_body` (together with `recipient_email` and `sender_email`) is required. This endpoint automatically adds: * An unsubscribe footer if the HTML does not include the unsubscribe URL. * The `List-Unsubscribe` and `List-Unsubscribe-Post` headers (RFC 8058). * The `view_in_browser_url` and `unsubscribe_url` variables (if you don't send them yourself). Recipient replies go to the sender's inbox — see [Automatic Reply-To](#automatic-reply-to-inbound-email). ### Example with template UUID ```bash theme={null} curl -X POST https://api.reallyquickemails.com/v1/send-template-email \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" \ -H "Content-Type: application/json" \ -d '{ "template_id": "550e8400-e29b-41d4-a716-446655440000", "recipient_email": "new.user@example.com", "sender_email": "onboarding@myapp.com", "variables": { "name": "Carlos", "plan": "Pro", "trial_days": 14, "dashboard_url": "https://myapp.com/dashboard" } }' ``` ```python theme={null} import requests resp = requests.post( "https://api.reallyquickemails.com/v1/send-template-email", headers={"Authorization": "Bearer sk_proj_xxxxxxxxxxxx"}, json={ "template_id": "550e8400-e29b-41d4-a716-446655440000", "recipient_email": "new.user@example.com", "sender_email": "onboarding@myapp.com", "variables": { "name": "Carlos", "plan": "Pro", "trial_days": 14, "dashboard_url": "https://myapp.com/dashboard", }, }, ) print(resp.json()) ``` ### Example with template internal ID Each template has an auto-incremented internal ID within the project. Useful for integrations that prefer numeric IDs: ```bash theme={null} curl -X POST https://api.reallyquickemails.com/v1/send-template-email \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" \ -H "Content-Type: application/json" \ -d '{ "template_internal_id": 5, "recipient_email": "customer@example.com", "sender_email": "noreply@myapp.com", "variables": { "name": "Maria" } }' ``` ```python theme={null} import requests resp = requests.post( "https://api.reallyquickemails.com/v1/send-template-email", headers={"Authorization": "Bearer sk_proj_xxxxxxxxxxxx"}, json={ "template_internal_id": 5, "recipient_email": "customer@example.com", "sender_email": "noreply@myapp.com", "variables": { "name": "Maria", }, }, ) print(resp.json()) ``` **Response** `200 OK` ```json theme={null} { "message": "Email sent successfully", "email_id": "550e8400-e29b-41d4-a716-446655440000", "project_id": "123e4567-e89b-12d3-a456-426614174000", "template_id": "550e8400-e29b-41d4-a716-446655440000", "template_internal_id": null, "variables_used": ["name", "plan", "trial_days", "dashboard_url", "view_in_browser_url", "unsubscribe_url"], "used_cached_html": true } ``` `variables_used` includes the automatically injected variables (`view_in_browser_url`, `unsubscribe_url`). `used_cached_html` is `true` when the template's pre-rendered HTML was used. ### Response when the recipient is suppressed (200) If the recipient unsubscribed or bounced, the email is skipped automatically: **Response** `200 OK` ```json theme={null} { "message": "Email skipped — recipient is suppressed", "skipped": true, "suppression_reason": "unsubscribed", "recipient": "customer@example.com" } ``` ### Error Codes | Code | Description | | ----- | -------------------------------------------------------------------------------------------------------------------- | | `400` | `Missing required fields: template_id/template_internal_id, OR recipient_email + sender_email + html_body` | | `400` | `Missing required fields: recipient_email, sender_email` | | `400` | `template_internal_id requires valid project context` | | `400` | `ENVIRONMENT_NOT_CONFIGURED` — the `environment` is not configured in the project. | | `401` | Invalid or missing API Key. | | `404` | `Template not found with ID ...` — template not found for the project associated with the API Key. | | `422` | `TEMPLATE_EMPTY` — the template renders to empty content. Re-save the template in the editor to regenerate the HTML. | | `500` | Internal server error. | Learn more in [Templates](/en/guides/templates). *** ## POST /v1/send-batch Send bulk emails in a single request — up to **10,000 recipients** per call. ### Request Body | Field | Type | Required | Description | | ---------------- | ------- | -------- | ---------------------------------------------------------------------------------------------------------------------- | | `sender` | string | Yes | Sender email address (verified domain). | | `senderName` | string | No | Sender display name. | | `subject` | string | Yes\* | Email subject. Required if `templateId` is not used. | | `html` | string | Yes\* | HTML content. Required if `templateId` is not used. | | `templateId` | string | Yes\* | Template UUID. Alternative to `subject` + `html`. | | `email_type` | string | No | Nature of the send: `transactional` (default) or `marketing`. See [Send Type](/en/api-reference/send-email#send-type). | | `scheduled_at` | string | No | ISO 8601 date for scheduled sending. | | `custom_headers` | object | No | Batch-level headers. Only `List-Unsubscribe` and `List-Unsubscribe-Post` are applied. | | `environment` | string | No | Routes webhooks to the configured environment. Format `[a-zA-Z0-9_.-]`, max 64 characters. | | `dry_run` | boolean | No | Previews the batch without queuing emails or creating activity records. See [Dry run](#dry-run). | | `recipients` | array | Yes | List of recipients (maximum 10,000). | \*You must send `templateId` OR both `subject` + `html`. **`email_type` now defaults to `transactional`** (it used to be `marketing` on this endpoint only, unlike the rest of the API). If you send campaigns through `send-batch`, **declare `email_type: "marketing"` explicitly**: without the field, the send does not honour voluntary unsubscribes. Bounces and complaints keep blocking in both cases. **Structure of each recipient:** | Field | Type | Required | Description | | ---------------- | ------ | -------- | -------------------------------------------- | | `email` | string | Yes | Recipient email address. | | `data` | object | No | Custom variables (Handlebars). | | `custom_headers` | object | No | Per-recipient headers. Override the batch's. | ### Headers | Header | Type | Required | Description | | ----------------- | ------ | -------- | -------------------------------------------------------------------- | | `Idempotency-Key` | string | No | Idempotency key (1–256 characters). See [Idempotency](#idempotency). | ### Example with direct HTML ```bash theme={null} curl -X POST https://api.reallyquickemails.com/v1/send-batch \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" \ -H "Content-Type: application/json" \ -d '{ "sender": "noreply@yourdomain.com", "senderName": "My Company", "subject": "Special offer for you, {name}", "html": "

Hi {name}!

We have a special offer on {product}.

", "recipients": [ { "email": "juan@example.com", "data": { "name": "Juan", "product": "Pro Plan" } }, { "email": "maria@example.com", "data": { "name": "Maria", "product": "Business Plan" } } ] }' ``` ```ts theme={null} import { RQE } from '@reallyquickemails/sdk'; const rqe = new RQE({ apiKey: process.env.RQE_API_KEY }); const { data, error } = await rqe.emails.sendBatch({ sender: 'noreply@yourdomain.com', senderName: 'My Company', subject: 'Special offer for you, {name}', html: '

Hi {name}!

We have a special offer on {product}.

', recipients: [ { email: 'juan@example.com', data: { name: 'Juan', product: 'Pro Plan' } }, { email: 'maria@example.com', data: { name: 'Maria', product: 'Business Plan' } }, ], }); if (error) console.error(error); else console.log('Batch queued:', data.batch_id); ``` ```python theme={null} import requests resp = requests.post( "https://api.reallyquickemails.com/v1/send-batch", headers={"Authorization": "Bearer sk_proj_xxxxxxxxxxxx"}, json={ "sender": "noreply@yourdomain.com", "senderName": "My Company", "subject": "Special offer for you, {name}", "html": "

Hi {name}!

We have a special offer on {product}.

", "recipients": [ { "email": "juan@example.com", "data": {"name": "Juan", "product": "Pro Plan"}, }, { "email": "maria@example.com", "data": {"name": "Maria", "product": "Business Plan"}, }, ], }, ) print(resp.json()) ``` ### Example with template ```bash theme={null} curl -X POST https://api.reallyquickemails.com/v1/send-batch \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" \ -H "Content-Type: application/json" \ -d '{ "sender": "noreply@yourdomain.com", "senderName": "My Company", "templateId": "550e8400-e29b-41d4-a716-446655440000", "recipients": [ { "email": "juan@example.com", "data": { "name": "Juan" } }, { "email": "maria@example.com", "data": { "name": "Maria" } } ] }' ``` ```ts theme={null} import { RQE } from '@reallyquickemails/sdk'; const rqe = new RQE({ apiKey: process.env.RQE_API_KEY }); await rqe.emails.sendBatch({ sender: 'noreply@yourdomain.com', senderName: 'My Company', templateId: '550e8400-e29b-41d4-a716-446655440000', recipients: [ { email: 'juan@example.com', data: { name: 'Juan' } }, { email: 'maria@example.com', data: { name: 'Maria' } }, ], }); ``` ```python theme={null} import requests resp = requests.post( "https://api.reallyquickemails.com/v1/send-batch", headers={"Authorization": "Bearer sk_proj_xxxxxxxxxxxx"}, json={ "sender": "noreply@yourdomain.com", "senderName": "My Company", "templateId": "550e8400-e29b-41d4-a716-446655440000", "recipients": [ {"email": "juan@example.com", "data": {"name": "Juan"}}, {"email": "maria@example.com", "data": {"name": "Maria"}}, ], }, ) print(resp.json()) ``` ### Example with scheduled send ```bash theme={null} curl -X POST https://api.reallyquickemails.com/v1/send-batch \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" \ -H "Content-Type: application/json" \ -d '{ "sender": "noreply@yourdomain.com", "subject": "Weekly newsletter", "html": "

Newsletter

News from this week...

", "scheduled_at": "2026-03-25T10:00:00Z", "recipients": [ { "email": "sub1@example.com" }, { "email": "sub2@example.com" } ] }' ``` ```ts theme={null} import { RQE } from '@reallyquickemails/sdk'; const rqe = new RQE({ apiKey: process.env.RQE_API_KEY }); await rqe.emails.sendBatch({ sender: 'noreply@yourdomain.com', subject: 'Weekly newsletter', html: '

Newsletter

News from this week...

', scheduled_at: '2026-03-25T10:00:00Z', recipients: [ { email: 'sub1@example.com' }, { email: 'sub2@example.com' }, ], }); ``` ```python theme={null} import requests resp = requests.post( "https://api.reallyquickemails.com/v1/send-batch", headers={"Authorization": "Bearer sk_proj_xxxxxxxxxxxx"}, json={ "sender": "noreply@yourdomain.com", "subject": "Weekly newsletter", "html": "

Newsletter

News from this week...

", "scheduled_at": "2026-03-25T10:00:00Z", "recipients": [ {"email": "sub1@example.com"}, {"email": "sub2@example.com"}, ], }, ) print(resp.json()) ``` **Response** `200 OK` ```json theme={null} { "batch_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890", "total": 2, "queued": 2, "scheduled": false, "scheduled_for": null, "activities": [ { "email": "juan@example.com", "activity_id": "uuid-1" }, { "email": "maria@example.com", "activity_id": "uuid-2" } ] } ``` | Field | Type | Description | | --------------- | -------------- | --------------------------------------------------------------- | | `batch_id` | string | Unique batch UUID for reference. | | `total` | number | Total number of recipients. | | `queued` | number | Number of emails queued for sending. | | `scheduled` | boolean | `true` if `scheduled_at` is in the future. | | `scheduled_for` | string \| null | The `scheduled_at` value sent, or `null` if immediate. | | `activities` | array | List with `email` and `activity_id` per recipient for tracking. | Each recipient's `activity_id` lets you track delivery status via webhooks. As in `/v1/send-email`, applied when processing each send in the background — suppressed recipients are skipped and their activity remains with status `suppressed`. ### Idempotency Send the optional `Idempotency-Key` header (1–256 characters) to avoid duplicates on retries. 2xx and 4xx responses are cached for **24 hours**, scoped per project. If you repeat the key within that window, you receive the cached response without reprocessing the batch, with the `Idempotency-Replayed: true` header. In the Node.js SDK, pass it as the second argument: `rqe.emails.sendBatch(params, { idempotencyKey })`. Learn more in [Node.js SDK](/en/guides/sdk-nodejs). ### Dry run With `"dry_run": true`, the API returns a preview without queuing emails or creating activity records: ```json theme={null} { "dry_run": true, "test_mode": false, "recipients_count": 2, "would_send": { "template_id": null, "subject": "Special offer for you, {name}", "from": "My Company ", "first_recipient": "juan@example.com" } } ``` ### Limits | Limit | Value | | ---------------------- | -------- | | Recipients per request | 10,000 | | Idempotency cache | 24 hours | For more than 10,000 recipients, use multiple calls or create a campaign from the RQE Dashboard, which handles batching and retries automatically. Learn more in [Campaigns](/en/api-reference/campaigns). ### Error Codes | Code | Description | | ----- | ---------------------------------------------------------------------------------- | | `400` | `sender is required` | | `400` | `subject or templateId is required` | | `400` | `html or templateId is required` | | `400` | `recipients array is required and must not be empty` | | `400` | `Too many recipients: X. Maximum is 10,000 per batch.` | | `400` | `recipients[N].email is required` | | `400` | `environment must be a string of [a-zA-Z0-9_.-] up to 64 chars` | | `400` | `ENVIRONMENT_NOT_CONFIGURED` — the `environment` is not configured in the project. | | `401` | Invalid or missing API Key. | | `500` | `Failed to create activity records` / `Failed to process batch` | ### Manage a scheduled batch A batch created with a future `scheduled_at` can be inspected, rescheduled, or cancelled while it has not gone out yet. Use the `batch_id` returned by `POST /v1/send-batch`, with the same `sk_proj_...` Bearer token. #### GET /v1/send-batch/:batchId Returns the status of a scheduled batch that has not gone out yet. ```bash theme={null} curl https://api.reallyquickemails.com/v1/send-batch/a1b2c3d4-e5f6-7890-abcd-ef1234567890 \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" ``` **Response** `200 OK` ```json theme={null} { "batch_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890", "pending": 120, "cancellable": true } ``` | Field | Type | Description | | ------------- | ------- | ---------------------------------------------------------------------------------- | | `batch_id` | string | Batch UUID. | | `pending` | number | Jobs still queued with a delay. `0` = the batch already went out or was cancelled. | | `cancellable` | boolean | `true` while there are pending jobs that can be cancelled. | #### PATCH /v1/send-batch/:batchId Reschedules a pending batch to a new date. | Field | Type | Required | Description | | -------------- | ------ | -------- | ----------------------------------------- | | `scheduled_at` | string | Yes | New ISO 8601 date. Must be in the future. | ```bash theme={null} curl -X PATCH https://api.reallyquickemails.com/v1/send-batch/a1b2c3d4-e5f6-7890-abcd-ef1234567890 \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" \ -H "Content-Type: application/json" \ -d '{ "scheduled_at": "2026-08-01T10:00:00Z" }' ``` **Response** `200 OK` ```json theme={null} { "batch_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890", "rescheduled": 120, "scheduled_for": "2026-08-01T10:00:00.000Z" } ``` `rescheduled` is the number of jobs rescheduled to the new date. | Code | Description | | ----- | --------------------------------------------------------------------------- | | `400` | `INVALID_INPUT` — invalid `scheduled_at` or a date in the past. | | `404` | `NOT_FOUND` — the batch already went out, was cancelled, or does not exist. | #### DELETE /v1/send-batch/:batchId Cancels a scheduled batch **before** it goes out. ```bash theme={null} curl -X DELETE https://api.reallyquickemails.com/v1/send-batch/a1b2c3d4-e5f6-7890-abcd-ef1234567890 \ -H "Authorization: Bearer sk_proj_xxxxxxxxxxxx" ``` **Response** `200 OK` ```json theme={null} { "batch_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890", "cancelled": 120, "activities_updated": 120 } ``` `cancelled` is the number of jobs removed from the queue; `activities_updated`, the activity records marked as `cancelled`. | Code | Description | | ----- | --------------------------------------------------------------------------- | | `404` | `NOT_FOUND` — the batch already went out, was cancelled, or does not exist. | These endpoints only apply to batches with a future `scheduled_at` that have not gone out yet. An immediate batch (without `scheduled_at`) is queued instantly and cannot be cancelled. The activities of a cancelled batch are left with status `cancelled` and the reason in `error_code`/`error_message`. *** ## Automatic Reply-To (Inbound Email) Emails from `/v1/send-email` and `/v1/send-batch` automatically include a `Reply-To` header with the sender's name: ``` Reply-To: "My Company" ``` Email clients (Gmail, Outlook, Apple Mail) display the **sender's name**, not the technical address. When the recipient replies, the reply is routed to RQE and associated with the original thread. No configuration required. To receive notifications of incoming replies, configure an [inbound email webhook](/en/api-reference/webhooks#inbound-replies-with-attachments). In `/v1/send-template-email`, replies go directly to the sender's inbox: the `Reply-To` uses the reply address configured in the sender's profile, or `sender_email` itself if there is none. *** ## Data Management APIs Besides sending, the v1 API includes endpoints to manage leads, events, tags, and attributes. Full documentation at: * **[Leads API](/en/api-reference/leads)** — CRUD for leads, segments, tags, and attributes * **[Events API](/en/api-reference/events)** — Custom event tracking from your apps ### Quick summary | Category | Endpoint | Description | | -------------- | ------------------------------------------ | ------------------------------------------------ | | **Leads** | `POST /v1/leads` | Create/update leads (single or bulk up to 1,000) | | | `GET /v1/leads` | List with pagination and filters | | | `GET /v1/leads/:id` | Lead detail with segments | | | `PUT /v1/leads/:id` | Update lead | | | `DELETE /v1/leads/:id` | Delete lead | | **Segments** | `POST /v1/leads/:id/segments` | Add lead to segments | | | `DELETE /v1/leads/:id/segments/:segmentId` | Remove from segment | | **Tags** | `POST /v1/leads/:email/tags` | Add tags | | | `DELETE /v1/leads/:email/tags` | Remove tags | | | `GET /v1/leads/:email/tags` | List tags | | **Attributes** | `POST /v1/leads/:email/attributes` | Set/merge custom attributes | | | `GET /v1/leads/:email/attributes` | Get attributes | | **Events** | `POST /v1/events` | Track an event | | | `POST /v1/events/bulk` | Track up to 1,000 events | | | `GET /v1/events` | List events with filters |