TypeScript

nextmail.emails

Every method in this namespace: its signature, its parameters, what it returns and an example.

Methods

Send mail now or later, in batches or translated, and follow what happened to it.

`nextmail.emails.send()`

Send, schedule or translate and send one email

emails:send

Signature

send(body: EmailSend, options?: SendScope): Promise<SentEmailResource>

Sends one message now, or holds it for later with scheduledAt or an undo window with cancellableForSeconds. The body comes from exactly one source: html and or text, a stored template, or an existing draftId. Naming none is a 422, and template alongside html, text or draftId is refused. An immediate send is dispatched inside the request, so the promise usually settles on a sent, partial or failed message. A held send settles as queued or scheduled, so read status rather than treating a resolved promise as delivered mail.

Every call carries an Idempotency-Key. The SDK generates one per call and reuses it on that call's retries, and the API claims it against the key's own unique index before anything is dispatched, so a retried network failure replays the original message instead of sending a second one. Pass options.idempotencyKey to extend that across processes and restarts, deriving it from what made the send necessary rather than from a clock. A replay resolves with replayed: true and the stored message in its current state. The same key with a different body is a 422 idempotency_key_reuse.

Add translate to deliver the message in the recipient's language. The translation runs when the request is accepted, before any record exists, so a scheduled send carries the approved wording and a translation that cannot be produced refuses the whole send: nothing is ever delivered untranslated as a fallback. By default the subject is translated too and your original text is placed below the translation, captioned in the target language. It works with template, translating what the template rendered, and is refused alongside draftId because a draft goes as it was written.

Parameters

body.fromRecipientInputRequired: Sender as billing@acme.com, Acme Billing <billing@acme.com> or { email, name }. It must be an address the key may send as, otherwise 403 from_address_forbidden.
body.toRecipientInput | Array<RecipientInput>Required: One recipient or a list. to, cc and bcc together hold at most 50 addresses, and more is a 422 too_many_recipients.
body.ccRecipientInput | Array<RecipientInput>: Copy recipients, counted toward the 50 recipient ceiling.
body.bccRecipientInput | Array<RecipientInput>: Blind copy recipients, counted toward the 50 recipient ceiling.
body.replyToRecipientInput: Written into the Reply-To header.
body.subjectstring: At most 998 characters. Falls back to the template or draft subject when empty.
body.htmlstring: HTML body, at most 1,000,000 characters.
body.textstring: Plain text body, at most 1,000,000 characters.
body.template{ id: string, version?: number, props?: Record<string, unknown>, slots?: Record<string, unknown> }: A stored template by id or slug. Omitting version resolves whatever is published at that moment, so pin it when somebody else owns the copy.
body.draftIdstring: Sends an existing draft as written. Cannot be combined with template or translate.
body.threadIdstring: Files the sent message into an existing thread.
body.headersRecord<string, string>: Custom headers limited to X-*, List-*, Reply-To, Precedence, Auto-Submitted, Importance, Priority and Feedback-ID. Anything the server sets itself is a 422 reserved_header.
body.attachmentsArray<AttachmentInput>: At most 20 files. Each entry is an inline file, with filename and content as bytes or a base64 string (bytes are encoded for you, and inline files are capped at 10 MB in total once decoded), a file at an https address as { url, filename?, contentType? }, fetched once when the message is accepted, or a stored file as { fileId } naming a file already uploaded to the workspace, up to 100 MB. Inline and url files come to at most 25 MB together; an address that cannot be fetched is a 422 attachment_unreachable.
body.attachmentDeliveryAttachmentDeliveryMode: How the files in attachments travel. mime carries them inside the message, so files that come to more than 25 MB together are refused. link uploads each file and puts a download link in the body in its place, so the message itself stays small. auto links when the files together come to more than 25 MB, or to more than 2 MB when the from domain has an active files domain, and attaches them otherwise. Left out, the sender's mailbox setting applies, and that defaults to auto.
body.scheduledAtDate | string: A Date, an ISO 8601 instant or a duration such as PT1H or P2D. At least one second and at most 365 days out.
body.followUpAtDate | string: Asks to be reminded if nobody replies: a Date, an ISO 8601 instant or a duration from now such as P3D, later than the time the message goes out and at most 365 days out. If no real reply has arrived by then, the thread returns to the top of the inbox, unread, with a push. followUps.list lists the reminders and followUps.cancel cancels one.
body.cancellableForSecondsnumber: An undo window from 0 to 900 seconds on an immediate send. Refused alongside scheduledAt, which is already cancellable until it goes.
body.tracking{ opens?: boolean, clicks?: boolean }: Overrides the tracking setting for this send. A field left out takes the setting of the address it is sent from: its own, else its domain catch-all's when the catch-all caught that address, else off.
body.signatureboolean: An html body goes out exactly as written, so it carries a signature only when this is true, while a text-only body carries one unless this is false. When it is added it is the default signature of the address it is sent from: the one it keeps for replies when the message answers a thread (threadId or an In-Reply-To header), and the one for new mail otherwise. An address with no signature of its own takes its domain catch-all's when the catch-all caught that address, else the Nextmail footer unless that address turned the footer off. signatureId picks another signature of the address. Template sends and encrypted sends never carry one.
body.signatureIdstring: Adds one particular signature of the from address in place of its default, by the id signatures.list returns. It signs an html body too, so signature: true is not needed with it, and it cannot be combined with signature: false. An id that is not a signature of the from address is a 422 invalid_parameter. When the signature is deleted before a scheduled message goes out, the message carries the default of the address instead.
body.tagsRecord<string, string>: Up to 10 tags, keys of 1 to 64 letters, digits, _ or -, values up to 256 characters. Echoed back on every read.
body.streamSendStream: The lane the message travels in: transactional, the default, for mail one person is waiting for, or broadcast for newsletters and other mail to many people. Each lane has its own queue and its own reputation.
body.translateSendTranslateOptions: { to, from?, includeOriginal?, subject? }. to takes a code, an English name or an endonym. includeOriginal and subject both default to true.
options.idempotencyKeystring: Your own key, 1 to 255 characters of letters, digits, _, ., : or -. Anything else is a 400 invalid_idempotency_key.
options.signalAbortSignal: Cancels the request. An aborted send may still have been accepted, so retry with the same idempotencyKey.
options.apiKeystring: Sends with this key instead of the client's, for a process sending on behalf of several workspaces.

Returns

SentEmailResource, an EmailResource plus replayed. Notable fields are id (msg_ plus 24 hex), status, mode, from, subject, scheduledAt, cancellableUntil, sentAt, lastError, tags, stream and, on a translated send, translation.

Example

const sent = await nextmail.emails.send({    from: 'Acme Billing <billing@acme.com>',    to: 'ada@example.de',    subject: 'Your September invoice',    html: '<p>The invoice is attached. Tell me if anything on it looks wrong.</p>',    translate: { to: 'de' },    tags: { invoice: 'inv_2026_09_4192' }}, {    idempotencyKey: 'invoice:inv_2026_09_4192'}) console.log(sent.id, sent.status, sent.replayed, sent.translation?.language)

Notes

A message sent with stream set to broadcast while that lane is paused for too many bounces or complaints is refused with 409 stream_paused. sending.listStreams shows why, and app mail on the transactional lane still goes.
On the broadcast lane, a message to one recipient whose headers hold no List-Unsubscribe gets List-Unsubscribe and List-Unsubscribe-Post for one-click unsubscribe. Whoever uses them joins the unsubscribe list that suppressions.listUnsubscribes reads, and broadcast lane mail is not sent to anybody on that list: the recipient is suppressed and email.suppressed says why. Transactional mail still reaches them.
A from on a domain that is known to the workspace but cannot sign mail yet is refused up front with 409 domain_not_sendable and param set to from, so nothing is accepted that would only fail at dispatch. addresses.list shows the same verdict as canSend before you send.
A test key (oe_test_) never delivers. The message is marked sent with transport set to test and every recipient delivered, so assert on the response and not on an inbox.
The idempotency fingerprint covers the template version the send resolved to. Retrying an unpinned template send after somebody publishes a new version is a 422 idempotency_key_reuse, not a replay. scheduledAt is left out of the fingerprint.
A spent send allowance is a 429 send_quota_exceeded with no Retry-After, and it resets on the first of the month. The SDK does not retry a 429 that carries no Retry-After, so it throws straight away.
Translation failures refuse the send: 409 translation_not_configured when the workspace has no AI, 422 translation_too_long past 30,000 characters, 429 ai_quota_exceeded when the workspace has used today's AI actions, and 503 translation_failed when the provider did not answer.
A translated send spends one AI action. isRetryable is true for every 429, but ai_quota_exceeded fails the same way until the allowance resets at midnight UTC, so show it to a person or send without translate.
A followUpAt that is not later than the time the message goes out, or is more than 365 days out, refuses the send with a 422 whose param is followUpAt, coded invalid_follow_up or invalid_parameter, and nothing is sent. The SDK converts a Date with toISOString(), as it does for scheduledAt.

Also available in

API: POST /emails
Python: emails.send()
Ruby: emails.send
PHP: emails->send
Go: Emails.Send
Java: emails().send
C#: Emails.SendAsync
CLI: nextmail emails send

`nextmail.emails.sendBatch()`

Send up to 100 independent emails in one request

emails:send

Signature

sendBatch(emails: Array<EmailSend>, options?: SendScope): Promise<BatchResultResource>

Sends each message in order, as if emails.send had been called for it, and reports per item. It is never all or nothing: a bad address on item 7 fails item 7 and the rest still go, because a batch that rolled back would turn your retry into a guess about which messages had already been delivered. The promise resolves whenever the batch was processed, so check failed and each item's status rather than relying on a throw.

The batch shares one Idempotency-Key, generated once per call or supplied as options.idempotencyKey, and the server derives a separate key per item from it and the item's position. Retrying the same array replays the items that already went and sends only the ones that did not. Reordering the array between attempts changes which body each position's key is bound to, so an item that moved comes back as an idempotency_key_reuse error.

Apart from a key or scope failure or a server fault, only problems with the batch as a whole reject the promise with a 422: an empty array, more than 100 messages, or more than 10 messages carrying translate. Translation costs several model calls per message and they run one after another, so a larger translated batch would time out partway. Split it, or schedule the messages instead.

Parameters

emailsArray<EmailSend>Required: Between 1 and 100 messages, each shaped exactly like the body of emails.send, followUpAt included, and validated on its own.
options.idempotencyKeystring: Your own batch key, 1 to 255 characters of letters, digits, _, ., : or -.
options.signalAbortSignal: Cancels the request. Items processed before the abort may already have been sent.
options.apiKeystring: Sends the batch with this key instead of the client's.

Returns

BatchResultResource with sent, failed and items. Each item has its index and either status: 'ok' with the email (a SentEmailResource) or status: 'error' with an error carrying type, code, message and, when a field is to blame, param.

Example

const result = await nextmail.emails.sendBatch([    { from: 'dispatch@acme.com', to: 'ada@example.com', subject: 'Order AC-4192 has shipped', text: 'It is on its way.' },    { from: 'dispatch@acme.com', to: 'grace@example.com', subject: 'Order AC-4193 has shipped', text: 'It is on its way.' }], {    idempotencyKey: 'shipments:2026-09-15'}) for (const item of result.items) {    if (item.status === 'error') console.error(item.index, item.error.code, item.error.message)} console.log(result.sent, result.failed)

Notes

Each entry is authorised on its own, so a from on a domain that cannot sign yet fails that entry with domain_not_sendable while the rest go.
Once the send allowance of the workspace runs out partway, every remaining item fails with send_quota_exceeded while the earlier ones stay sent. It is counted for that workspace alone, so sends from other workspaces never spend it. A workspace on a paid plan with pay as you go turned on keeps sending past it instead.
Each item with translate spends one AI action. Once that account has used today's AI actions, every remaining item with translate fails with ai_quota_exceeded while items without it still go. Retrying those items fails the same way until the allowance resets at midnight UTC, unless the account has pay as you go turned on.
An unexpected server fault aborts the batch with a 500 after the earlier items have gone. The SDK retries it with the same key, which replays those items instead of sending them twice.
Items are processed one after another inside a single request, so a large batch of immediate sends takes noticeably longer than one send. Keep the client timeoutMs generous.

Also available in

API: POST /emails/batch
Python: emails.send_batch()
Ruby: emails.send_batch
PHP: emails->sendBatch
Go: Emails.SendBatch
Java: emails().sendBatch
C#: Emails.SendBatchAsync
CLI: nextmail emails send-batch

`nextmail.emails.translate()`

Preview a translation without sending anything

emails:send

Signature

translate(body: EmailTranslate, options?: RequestScope): Promise<TranslationResource>

Runs the same translation translate performs on a send and stops one step early. The same function produces both, so what comes back is what would go out. Nothing is stored and nothing is sent. Use it when somebody should read the translated wording before it reaches a recipient.

Send the approved result as an ordinary subject and html on emails.send with no translate option. Passing translate again translates a second time, moving the wording off the version that was signed off and discarding any edits. When includeOriginal is on, html already contains your original text below the translation, so do not append your own copy.

At least one of html, text or subject is required. to accepts a BCP-47 code, an English name or the language's own name, and the response reports the code it settled on in language.code, which is the form worth storing. State from to skip language detection. Otherwise it is detected from the body, and a detector that cannot tell returns null in detectedSourceLanguage rather than guessing.

Parameters

body.tostringRequired: Target language as a code (de), English name (German) or endonym (Deutsch). An unrecognised value is a 422 invalid_parameter on to.
body.fromstring: The language you wrote in. Stating it skips the detection call.
body.includeOriginalboolean: Defaults to true, placing your original text below the translation under a caption in the target language.
body.subjectstring: Subject line to translate, at most 998 characters.
body.htmlstring: HTML body to translate. Only the content inside <body> is sent to the model when the markup is a full document.
body.textstring: Plain text body to translate. Translated separately when given alongside html.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Runs the preview with this key instead of the client's.

Returns

TranslationResource with object set to translation, language and detectedSourceLanguage as full LanguageResource rows, subject, html and text (each null when that input was not given) and includeOriginal.

Example

const preview = await nextmail.emails.translate({    to: 'ja',    subject: 'Your September invoice',    html: '<p>The invoice is attached.</p>'}) console.log(preview.language.native, preview.detectedSourceLanguage?.code) await nextmail.emails.send({    from: 'Acme Billing <billing@acme.com>',    to: 'ada@example.jp',    subject: preview.subject ?? 'Your September invoice',    html: preview.html ?? '<p>The invoice is attached.</p>'})

Notes

The SDK never retries this call. Each attempt spends one AI action, as a translated send does. Handle a 503 translation_failed yourself, and treat a 429 ai_quota_exceeded as final until the allowance resets at midnight UTC.
Anything over 30,000 characters is refused with 422 translation_too_long rather than truncated, since half a translation has no seam to show where it stopped.
A right-to-left target comes back with html wrapped in dir="rtl".
A workspace with no AI configured gets 409 translation_not_configured, and retrying will fail the same way.

Also available in

API: POST /emails/translate
Python: emails.translate()
Ruby: emails.translate
PHP: emails->translate
Go: Emails.Translate
Java: emails().translate
C#: Emails.TranslateAsync
CLI: nextmail emails translate

`nextmail.emails.check()`

Check how a message would be rated, without sending it

emails:send

Signature

check(body: EmailCheck, options?: RequestScope): Promise<EmailCheckResource>

Scores a message the way a receiving mailbox would, before it goes out: a spam score, a phishing score and an AI-writing score, each 0 to 100, with the signals behind each one. Nothing is stored and nothing is sent.

The same checks score every message that arrives in a mailbox on Nextmail, so what comes back is what a recipient on Nextmail sees in Details. It cannot know a recipient's own filter, sender history or reputation, so a low score is a good sign and not a delivery guarantee.

Run it before an automated send, or as someone writes, and fix what signals names. Sender authentication is taken as passing, since the message will be signed for your domain.

Parameters

body.subjectstring: Subject line, at most 998 characters.
body.htmlstring: HTML body. Links and images are read from it.
body.textstring: Plain text body. Taken from html when left out.
body.fromstring: The address it will be sent from.
body.fromNamestring: The display name it will carry. A name that claims another address or a known brand raises the phishing score.
body.replyTostring: A Reply-To on a different domain raises the phishing score.
body.replyingboolean: True when it answers an existing thread. A Re: subject on a message that answers nothing raises the spam score.
body.attachmentNamesArray<string>: File names, so an attachment that can run code is caught.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Runs the check with this key instead of the client's.

Returns

EmailCheckResource with object set to email_check and three scores. spam carries score, level (low, medium from 35, high from 60) and signals. phishing carries score, level (clear, caution from 30, danger from 60), signals and reasons. ai carries score (null when not judged), level, signals, reasons, words and skipped (too-short under 40 words).

Example

const check = await nextmail.emails.check({    from: 'billing@acme.com',    subject: 'Your September invoice',    html: '<p>The invoice is attached.</p>'}) if (check.spam.level !== 'low') console.log('Rework it first:', check.spam.signals) console.log(check.spam.score, check.phishing.score, check.ai.score)

Notes

It spends no AI action and never calls a model, so it is safe to run on every revision.
A score is not a probability. Each one adds up weighted signals, heaviest first in signals.

Also available in

API: POST /emails/check
Python: emails.check()
Ruby: emails.check
PHP: emails->check
Go: Emails.Check
Java: emails().check
C#: Emails.CheckAsync
CLI: nextmail emails check

`nextmail.emails.list()`

List one page of sent emails, newest first

emails:readPages through results

Signature

list(options?: EmailListOptions): Promise<Page<EmailResource>>

Returns one page of the workspace's send records, ordered newest first. Paging is keyset rather than offset: nextCursor is the id of the last message on the page, and passing it back as cursor continues strictly after it, so messages sent while you page never shift or repeat rows. hasMore is false on the last page and nextCursor is then null.

Filter with status, one value or an array that the SDK joins with commas, with from, which matches the sending address exactly and ignores case, with broadcastId, which keeps the copies of one broadcast, and with scheduledFrom and scheduledTo, which keep the messages scheduled inside a window. An unrecognised status is a 422 invalid_parameter naming the offending values, and a cursor that names no message in the workspace is a 400 invalid_cursor.

Rows are the summary form. They never carry recipients or translation, whose absence on a row says nothing either way, and a tracked message carries only the counts half of tracking: opens, clicks, opened, clicked, openCount, clickCount and firstOpenAt. Call get for per-recipient delivery state and getTracking for the full engagement report.

Parameters

options.statusEmailStatus | Array<EmailStatus>: One or more of queued, scheduled, sending, sent, partial, bounced, cancelled and failed.
options.fromstring: A bare sending address such as billing@acme.com, matched exactly and case insensitively. A display name form does not match.
options.broadcastIdstring: Only the copies of one broadcast, a brd_ id from broadcasts.send. Each person a broadcast reaches gets a message of their own, so this lists who it went to and what happened to each copy. An id that names no broadcast answers an empty page.
options.scheduledFromDate | string: Only messages scheduled for this instant or later. With scheduledTo and status: ['scheduled', 'queued'] it lists what is waiting to go out in a window, as the calendar of the app does. A message with no scheduledAt is left out.
options.scheduledToDate | string: Only messages scheduled for this instant or earlier. scheduledFrom after scheduledTo is a 422 invalid_parameter.
options.sinceDate | string: Only messages made at this instant or later.
options.untilDate | string: Only messages made before this instant. since after until is a 422 invalid_parameter.
options.recipientstring: Only messages that went to this address as a to, cc or bcc recipient, matched exactly.
options.tagstring: Only messages sent with this tag: name for any value, or name:value for one value. Tags are stored encrypted, so the match is exact and case-sensitive.
options.limitnumber: Rows per page, a whole number from 1 to 100, defaulting to 25. Outside that range is a 422.
options.cursorstring: The nextCursor from the previous page, which is a message id.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Lists with this key instead of the client's.

Returns

Page<EmailResource> with items, hasMore and nextCursor. Each item has id, status, mode, from, subject, transport, attempts, lastError, scheduledAt, cancellableUntil, sentAt, tags, broadcastId, source, createdAt and, when tracked, the trimmed tracking counts.

Example

const page = await nextmail.emails.list({    status: ['failed', 'partial'],    from: 'billing@acme.com',    limit: 50}) for (const email of page.items) console.log(email.id, email.status, email.lastError) if (page.hasMore) {    const next = await nextmail.emails.list({ status: ['failed', 'partial'], from: 'billing@acme.com', limit: 50, cursor: page.nextCursor ?? undefined })     console.log(next.items.length)}

Notes

With a narrowed key only messages sent from addresses it covers are read, and the page is cut after that filter, so every page but the last holds limit items. A key that holds a whole domain covers every address on it.
A from the key does not cover returns an empty last page rather than a 403.
tracking is absent, not zeroed, on a message that carried no pixel or rewritten link.

Also available in

API: GET /emails
Python: emails.list()
Ruby: emails.list
PHP: emails->list
Go: Emails.List
Java: emails().list
C#: Emails.ListAsync
CLI: nextmail emails list

`nextmail.emails.listAll()`

Collect every matching sent email into one array

emails:readPages through results

Signature

listAll(options?: EmailListOptions): Promise<Array<EmailResource>>

Follows nextCursor from page to page and resolves once the last page has been read, with every matching send record in one array, newest first. It accepts the same filters as list and returns the same summary rows, so there are no recipients or translation on them and tracking is the trimmed counts form.

Everything is held in memory before the promise settles, and a workspace's send history grows without bound. Narrow it with status or from, or switch to iterate when you want to stop early or process rows as they arrive. limit sets the page size of each underlying request, not the total, so a larger value means fewer round trips.

Parameters

options.statusEmailStatus | Array<EmailStatus>: One or more statuses to keep, joined with commas on the wire.
options.fromstring: A bare sending address, matched exactly and case insensitively.
options.broadcastIdstring: Only the copies of one broadcast, a brd_ id.
options.scheduledFromDate | string: Only messages scheduled for this instant or later.
options.scheduledToDate | string: Only messages scheduled for this instant or earlier.
options.sinceDate | string: Only messages made at this instant or later.
options.untilDate | string: Only messages made before this instant.
options.recipientstring: Only messages that went to this address as a to, cc or bcc recipient.
options.tagstring: Only messages sent with this tag: name for any value, or name:value for one value.
options.limitnumber: Page size per request, from 1 to 100, defaulting to 25 on the server.
options.cursorstring: A message id to start after, skipping everything newer.
options.signalAbortSignal: Cancels the request in flight and rejects the whole collection.
options.apiKeystring: Lists with this key instead of the client's.

Returns

Array<EmailResource> holding every row across all pages.

Example

const scheduled = await nextmail.emails.listAll({ status: 'scheduled', limit: 100 }) const dueToday = scheduled.filter((email) => email.scheduledAt?.startsWith('2026-09-15')) console.log(scheduled.length, dueToday.map((email) => email.id))

Notes

A failure on any page rejects the whole call, and the rows already fetched are discarded.
With a narrowed key only messages sent from addresses it covers are collected, and every page but the last is full.

Also available in

API: GET /emails
Python: emails.list_all()
Ruby: emails.list_all
PHP: emails->listAll
Go: Emails.ListAll
Java: emails().listAll
C#: Emails.ListAllAsync

`nextmail.emails.iterate()`

Stream sent emails one at a time across pages

emails:readPages through results

Signature

iterate(options?: EmailListOptions): AsyncGenerator<EmailResource, void, undefined>

Returns an async generator that yields send records individually, newest first, and requests the next page only once the current one is drained. Nothing is fetched until you start consuming it, and breaking out of the loop stops the requests, so this is the cheapest way to find the most recent message matching a condition the filters cannot express.

The walk is keyset based, following nextCursor from page to page. Mail sent while you iterate lands ahead of where you started and is never yielded, and nothing already yielded comes round again. Rows are the same summary form list returns.

Parameters

options.statusEmailStatus | Array<EmailStatus>: One or more statuses to keep, joined with commas on the wire.
options.fromstring: A bare sending address, matched exactly and case insensitively.
options.broadcastIdstring: Only the copies of one broadcast, a brd_ id.
options.scheduledFromDate | string: Only messages scheduled for this instant or later.
options.scheduledToDate | string: Only messages scheduled for this instant or earlier.
options.sinceDate | string: Only messages made at this instant or later.
options.untilDate | string: Only messages made before this instant.
options.recipientstring: Only messages that went to this address as a to, cc or bcc recipient.
options.tagstring: Only messages sent with this tag: name for any value, or name:value for one value.
options.limitnumber: Page size per request, from 1 to 100, defaulting to 25 on the server.
options.cursorstring: A message id to start after.
options.signalAbortSignal: Cancels the request in flight and ends the iteration with an error.
options.apiKeystring: Lists with this key instead of the client's.

Returns

AsyncGenerator<EmailResource, void, undefined> yielding one send record per step.

Example

for await (const email of nextmail.emails.iterate({ status: 'failed', limit: 100 })) {    if (email.tags.invoice === 'inv_2026_09_4192') {        console.log(email.id, email.lastError)        break    }}

Notes

The generator is lazy, so an abandoned loop costs only the pages you consumed.
With a narrowed key only messages sent from addresses it covers are yielded, and every page but the last is full.

Also available in

API: GET /emails
Python: emails.iterate()
Ruby: emails.iterate
PHP: emails->iterate
Go: Emails.Iterate
Java: emails().iterate
C#: Emails.IterateAsync

`nextmail.emails.get()`

Read one sent email with per-recipient state

emails:read

Signature

get(id: string, options?: RequestScope): Promise<EmailResource>

Returns the full send record for one message: its lifecycle status, delivery attempts and lastError, the schedule fields, and the two parts a list row leaves out. recipients has one entry per address with its own status, error and deliveredAt, and translation records what was done to a translated send.

A message that went out as a single call can still land differently per recipient. status on the message says how the send went as a whole, while each recipient moves on as delivery reports, bounces and complaints arrive. uncertain is a real recipient state: a transport that failed partway cannot say which recipients it reached. suppressed marks an address that previously bounced or complained in this workspace and was held back.

When the message was tracked, tracking carries the full engagement report with per-recipient and per-link detail. When it was not tracked, the field is absent rather than zeroed, because a message with no pixel has no evidence about whether anybody read it.

Parameters

idstringRequired: The send id, msg_ followed by 24 hex characters, as returned by send.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Reads with this key instead of the client's.

Returns

EmailResource with id, status, mode, from, subject, threadId, transport, attempts, lastError, scheduledAt, cancellableUntil, sentAt, tags, broadcastId, source, createdAt, recipients and, when present, translation and the full tracking report.

Example

const email = await nextmail.emails.get('msg_3f9a1c07d2b84e6a9c5b1f20') const undelivered = email.recipients?.filter((recipient) => recipient.status !== 'delivered') ?? [] console.log(email.status, undelivered.map((recipient) => [recipient.email, recipient.status, recipient.error]))

Notes

Do not correlate on messageId. The header is rewritten on the way out, so that value appears in no bounce or delivery report. Webhook events name the send by this id, as emailId.
A 404 never distinguishes a missing id from one in another workspace, and a narrowed key gets the same 404 for a message sent from an address it does not cover.
transport stays null until dispatch, and reads test on every message sent with a test key.

Also available in

API: GET /emails/{id}
Python: emails.get()
Ruby: emails.get
PHP: emails->get
Go: Emails.Get
Java: emails().get
C#: Emails.GetAsync
CLI: nextmail emails get

`nextmail.emails.listEvents()`

Read one page of the event trail of one sent email

emails:readPages through results

Signature

listEvents(id: string, options?: ListOptions): Promise<Page<EmailEventResource>>

Returns one page of everything recorded against one send, oldest first. Nothing is dropped from the trail, so following nextCursor while hasMore is true reaches its newest event, and listAllEvents and iterateEvents do that walk for you. It is the audit behind the current status: when the message was accepted or held, when it was rescheduled or cancelled, when it went out or failed, and every delivery report, bounce, complaint, open, click and file download attributed to it afterwards.

Each event has a dotted type and a data object whose shape depends on it. email.accepted, email.queued and email.scheduled open the trail with the source and recipient count. email.sent names the transport and messageId. email.failed carries the error. email.bounced and email.complained list the affected recipients and whether they were suppressed. email.delivered, email.rescheduled, email.cancelled, email.opened, email.clicked and email.downloaded follow as they happen. email.downloaded counts a person fetching a file that went out as a download link, never a scanner, and carries no recipient: the link is the same for everyone the message went to, so a download cannot be attributed. data is an empty object when an event carries nothing.

Webhooks deliver a subset of these same events as they occur, so this is where to look when a webhook was missed or never subscribed.

Parameters

idstringRequired: The msg_ send id whose trail to read.
options.limitnumber: Events per page, a whole number from 1 to 100, defaulting to 25.
options.cursorstring: The nextCursor from the previous page, which is an event id. One that names no event of this send is a 400 invalid_cursor.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Reads with this key instead of the client's.

Returns

Page<EmailEventResource> with items, hasMore and nextCursor. Each item has object set to event, id, type, data and createdAt.

Example

const page = await nextmail.emails.listEvents('msg_3f9a1c07d2b84e6a9c5b1f20', { limit: 100 }) const bounce = page.items.find((event) => event.type === 'email.bounced') console.log(page.items.map((event) => event.type), bounce?.data, page.hasMore)

Notes

email.delivered is recorded in this trail but is never sent as a webhook, so a delivery report surfaces only here and in recipients on get.
A send made with a test key records email.sent with transport: 'test' and simulated: true in data.
An unknown id is a 404, never an empty page.
A tracked message opened or clicked many times records one event per counted hit, so its trail can run to many pages.

Also available in

API: GET /emails/{id}/events
Python: emails.list_events()
Ruby: emails.list_events
PHP: emails->listEvents
Go: Emails.ListEvents
Java: emails().listEvents
C#: Emails.ListEventsAsync
CLI: nextmail emails list-events

`nextmail.emails.listAllEvents()`

Collect the whole event trail of one sent email into one array

emails:readPages through results

Signature

listAllEvents(id: string, options?: ListOptions): Promise<Array<EmailEventResource>>

Walks every page of one send's event trail and resolves with all of it, oldest first: acceptance, scheduling, sending, every delivery report, bounce and complaint, and every counted open, click and download afterwards.

A widely read message can hold a great many events, all in memory before the promise settles. Prefer iterateEvents when you can stop early. limit sets the page size of each request, not the total.

Parameters

idstringRequired: The msg_ send id whose trail to read.
options.limitnumber: Page size per request, from 1 to 100, defaulting to 25 on the server.
options.cursorstring: An event id to start after, skipping every older event.
options.signalAbortSignal: Cancels the request in flight and rejects the whole walk.
options.apiKeystring: Reads with this key instead of the client's.

Returns

Array<EmailEventResource> holding every event across all pages, oldest first.

Example

const events = await nextmail.emails.listAllEvents('msg_3f9a1c07d2b84e6a9c5b1f20', { limit: 100 }) const opens = events.filter((event) => event.type === 'email.opened').length console.log(events.length, opens)

Notes

A failure on any page rejects the whole call, and the events already fetched are discarded.
An unknown id is a 404 on the first page.

Also available in

API: GET /emails/{id}/events
Python: emails.list_all_events()
Ruby: emails.list_all_events
PHP: emails->listAllEvents
Go: Emails.ListAllEvents
Java: emails().listAllEvents
C#: Emails.ListAllEventsAsync

`nextmail.emails.iterateEvents()`

Stream the event trail of one sent email one event at a time

emails:readPages through results

Signature

iterateEvents(id: string, options?: ListOptions): AsyncGenerator<EmailEventResource, void, undefined>

Returns an async generator over one send's event trail that yields events individually, oldest first, and fetches the next page only when the current one is drained. Nothing is requested until you consume it, and breaking out of the loop stops further requests.

The walk moves forward in time, so events recorded while you iterate are yielded when the walk reaches them, and it ends when hasMore is false.

Parameters

idstringRequired: The msg_ send id whose trail to read.
options.limitnumber: Page size per request, from 1 to 100, defaulting to 25 on the server.
options.cursorstring: An event id to start after, skipping every older event.
options.signalAbortSignal: Cancels the request in flight and rejects the whole walk.
options.apiKeystring: Reads with this key instead of the client's.

Returns

AsyncGenerator<EmailEventResource, void, undefined> yielding one event per step.

Example

for await (const event of nextmail.emails.iterateEvents('msg_3f9a1c07d2b84e6a9c5b1f20')) {    if (event.type === 'email.delivered') {        console.log('delivered at', event.createdAt)        break    }}

Notes

The generator is lazy, so an abandoned loop costs only the pages you consumed.

Also available in

API: GET /emails/{id}/events
Python: emails.iterate_events()
Ruby: emails.iterate_events
PHP: emails->iterateEvents
Go: Emails.IterateEvents
Java: emails().iterateEvents
C#: Emails.IterateEventsAsync

`nextmail.emails.getTracking()`

Read the engagement report for a sent email

emails:read

Signature

getTracking(id: string, options?: RequestScope): Promise<TrackingResource>

Returns the same document tracking.get serves, reached from the msg_ id a sender already holds. It has the message totals, one entry per tracked copy under recipients, and every rewritten link with its clicks under links.

A message that was never tracked is a 404 here rather than an empty report. "We were not recording" and "nobody opened it" are different answers, and a client that renders them the same way makes a claim about a reader on no evidence. Tracking applies per send: opens and clicks record what was applied when the message went out, resolved from the setting of the address it was sent from (its own, else its domain catch-all's when the catch-all caught that address, else off) and any tracking override on the send, not what is switched on now.

Read every count as a floor. An open is inferred from a mail client fetching an image, so a reader whose client blocks images is never counted, and Gmail fetches the image once through its proxy and serves later views from cache. A click is stronger evidence than an open.

Parameters

idstringRequired: The msg_ send id returned by send.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Reads with this key instead of the client's.

Returns

TrackingResource with object set to tracking, id (the tmsg_ tracking id), sendId, opens, clicks, opened, clicked, attributable, openCount, clickCount, openCountRaw, clickCountRaw, the first and last open and click times, recipients and links.

Example

const report = await nextmail.emails.getTracking('msg_3f9a1c07d2b84e6a9c5b1f20') if (report.attributable) {    const unopened = report.recipients.filter((recipient) => recipient.attributed && recipient.openCount === 0)     console.log(unopened.map((recipient) => recipient.email))} console.log(report.openCount, report.links.map((link) => [link.url, link.clickCount]))

Notes

Only claim a named recipient has not opened when attributable is true. Mail that went to the whole list as one body has a shared copy whose email is null, and its opens cannot be pinned to anybody.
A message sent with a test key is never tracked, so this is always a 404 for one.
openCountRaw - openCount includes machine fetches such as Apple Mail Privacy Protection and repeats within thirty seconds, so do not read the difference as a pure machine count.

Also available in

API: GET /emails/{id}/tracking
Python: emails.get_tracking()
Ruby: emails.get_tracking
PHP: emails->getTracking
Go: Emails.GetTracking
Java: emails().getTracking
C#: Emails.GetTrackingAsync
CLI: nextmail emails get-tracking

`nextmail.emails.cancel()`

Stop a queued or scheduled email before it goes

emails:send

Signature

cancel(id: string, options?: RequestScope): Promise<EmailResource>

Cancels a message that has not been dispatched yet: a send held by scheduledAt, or an immediate send still inside its cancellableForSeconds undo window. The message moves to cancelled, nothing is delivered, and an email.cancelled event is recorded and sent to subscribed webhooks.

Only queued and scheduled messages can be cancelled. Once a message is sending, sent, partial, bounced or failed the call is a 409 email_not_cancellable, since there is no pending dispatch left to stop and mail that has gone cannot be recalled. An immediate send with no undo window is dispatched inside the send request, so by the time you hold its id it is usually past this point.

Cancelling is idempotent. Cancelling an already cancelled message resolves with the same cancelled message rather than an error, and the SDK retries the call after a network failure or a retryable status.

Parameters

idstringRequired: The msg_ send id to cancel.
options.signalAbortSignal: Cancels the HTTP request, not the email. Check status with get if you abort.
options.apiKeystring: Cancels with this key instead of the client's.

Returns

EmailResource in its new state, with status set to cancelled and scheduledAt and cancellableUntil still showing when it would have gone.

Example

const queued = await nextmail.emails.send({    from: 'billing@acme.com',    to: 'ada@example.com',    subject: 'Your September invoice',    text: 'Invoice attached.',    cancellableForSeconds: 30}) const cancelled = await nextmail.emails.cancel(queued.id) console.log(cancelled.status)

Notes

cancellableUntil on the message is the moment it stops being cancellable. Past it, expect the 409.
A cancelled message stays cancelled. There is no way to resume it, so send again if you change your mind.
A narrowed key gets a 404 for a message sent from an address it does not cover.

Also available in

API: POST /emails/{id}/cancel
Python: emails.cancel()
Ruby: emails.cancel
PHP: emails->cancel
Go: Emails.Cancel
Java: emails().cancel
C#: Emails.CancelAsync
CLI: nextmail emails cancel

`nextmail.emails.reschedule()`

Move a queued or scheduled email to a new send time

emails:send

Signature

reschedule(id: string, scheduledAt: Date | string, options?: RequestScope): Promise<EmailResource>

Changes when a message that has not gone yet will be dispatched. scheduledAt is the only thing this call can change, and the SDK sends nothing else: the body, recipients and any translation stay exactly as they were accepted.

The new time takes a Date, an ISO 8601 instant or a duration such as PT30M or P2D, measured from when the server receives the request. It must be at least one second in the future and at most 365 days out, otherwise the call is a 422 on scheduledAt, usually invalid_parameter. Earlier and later times are both allowed.

Only queued and scheduled messages can be moved. Anything already sending, sent, partial, bounced, cancelled or failed is a 409 email_not_cancellable. A queued message inside its undo window can be rescheduled too, which turns it into a scheduled send that stays cancellable until the new time.

Parameters

idstringRequired: The msg_ send id to move.
scheduledAtDate | stringRequired: The new send time. A Date is serialised with toISOString(), and a string is passed through as an instant or a duration.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Reschedules with this key instead of the client's.

Returns

EmailResource with status set to scheduled and scheduledAt and cancellableUntil both set to the new time.

Example

const tomorrowMorning = new Date('2026-09-16T08:00:00Z') const moved = await nextmail.emails.reschedule('msg_3f9a1c07d2b84e6a9c5b1f20', tomorrowMorning) console.log(moved.status, moved.scheduledAt)

Notes

The SDK retries this call after a network failure. A duration is resolved again on each attempt, so a retried PT1H lands an hour after the last attempt the server received.
An email.rescheduled event with the new scheduledAt is added to the trail on every successful move.
A translated scheduled message keeps its approved wording. To change the text itself, cancel it and send again.

Also available in

API: PATCH /emails/{id}
Python: emails.reschedule()
Ruby: emails.reschedule
PHP: emails->reschedule
Go: Emails.Reschedule
Java: emails().reschedule
C#: Emails.RescheduleAsync
CLI: nextmail emails reschedule

`nextmail.emails.update()`

Change an email that has not gone yet

emails:send

Signature

update(id: string, patch: EmailUpdate, options?: RequestScope): Promise<EmailResource>

Changes a queued or scheduled message before it is dispatched: when it goes with scheduledAt, what it says with subject, html and text, the address it goes out as with from, and who it goes to with to, cc and bcc. Send any of them together, and a field you leave out keeps its value. This is what editing a scheduled message in the calendar of the app does.

A recipient list replaces the stored one whole, and takes a string such as Ada <ada@example.com>, an object with email and name, or an array of either. from is checked as it is on a send, so it has to be an address the key may send as, or the call is a 403 from_address_forbidden.

Only messages that have not gone can change. Anything already sending, sent, partial, bounced, cancelled or failed is a 409 email_not_cancellable. A message translated when it was accepted keeps its approved wording, so a new subject, html or text on it is a 409 translation_locked, and one that was encrypted before it was scheduled keeps its wording and its recipients. Cancel those and send again instead.

Parameters

idstringRequired: The msg_ send id to change.
patch.scheduledAtDate | string: A new send time: a Date, an ISO 8601 instant or a duration such as PT2H, in the future and at most 365 days out.
patch.subjectstring: The new subject, up to 998 characters.
patch.htmlstring: The new HTML body.
patch.textstring: The new plain text body.
patch.fromstring: The address it goes out as instead, one the key may send as.
patch.toRecipientInput | Array<RecipientInput>: Replaces the recipients, at least one and at most 50 across the three lists.
patch.ccRecipientInput | Array<RecipientInput>: Replaces the copied recipients.
patch.bccRecipientInput | Array<RecipientInput>: Replaces the blind copied recipients.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Changes it with this key instead of the client's.

Returns

EmailResource, the message as it is now. Its subject, from and scheduledAt show the change.

Example

const updated = await nextmail.emails.update('msg_3f9a1c07d2b84e6a9c5b1f20', {    subject: 'Your September invoice, corrected',    to: ['ada@example.com', 'grace@example.com'],    scheduledAt: new Date('2026-10-05T08:00:00Z')}) console.log(updated.status, updated.subject, updated.scheduledAt)

Notes

The SDK retries this call after a network failure, which is safe because a repeat writes the same values.
An email.updated event naming the changed fields is added to the trail, and a move adds email.rescheduled as well.
reschedule is the same call with only scheduledAt.

Also available in

API: PATCH /emails/{id}
Python: emails.update()
Ruby: emails.update
PHP: emails->update
Go: Emails.Update
Java: emails().update
C#: Emails.UpdateAsync
CLI: nextmail emails update

`nextmail.emails.compose()`

Write an email with AI

emails:send

Signature

compose(body: EmailCompose, options?: RequestScope): Promise<EmailCompositionResource>

Writes the body of an email from prompt, an instruction, a rough draft or a few notes, in the style of the mail this workspace has sent before, as the composer of the app does. subject, to and cc help the greeting and the tone fit, and from, the address it goes out as, has it written as that address.

Give threadId to write a reply: the messages of that thread are read as context, which also needs threads:read, and a key limited to particular addresses can only use a thread that arrived at them.

Give draft, the body written so far, and prompt says what to change in it, as the describe bar of the composer does. withSubject: true adds subject to the answer. Give send, the send options as they stand, even {}, and prompt may change the recipients, the send time, tracking, the signature and the language: the answer's send holds only what changed, in the shape emails.send takes, and null takes an option away. Add send.fromOptions, the addresses it may go out as, and prompt may move it to one of them, which the answer names in send.from. Add send.encrypt, whether it is encrypted end to end as it stands, only when every recipient can receive encrypted mail, and prompt may turn encryption on or off. Times such as "tomorrow at 9" are read in timeZone, or the time zone of the account.

Give templates: true and prompt may switch the email to one of the workspace's published templates, which the answer names in template: pass template: { id: template.id } to emails.send in place of body, because the template's body replaces it. Give template, the id of the template the email uses now, and prompt leaves the body alone. Give files: true and prompt may attach files the workspace holds, found by their name: the answer lists them in attach, each ready to pass to emails.send as { fileId: id } in attachments, and names in attachMissing what matched no file. templates needs templates:read and files needs files:read, and each is ignored without its scope. A key limited to particular addresses only finds the files at those addresses.

Nothing is saved or sent. Pass body to emails.send or drafts.create when it reads right. Each call spends one of the workspace's AI actions, and a workspace that has used them all for the day is refused with a 429 ai_quota_exceeded.

Parameters

body.promptstringRequired: What to write, up to 20,000 characters. With draft, what to change in it, and it may be empty to have the draft finished as it is.
body.subjectstring: The subject so far, if there is one.
body.fromstring: The address it goes out as, so it is written as that address.
body.templatestring: The id of the template the email uses now, up to 128 characters. Its body is then the template, so prompt leaves the body alone.
body.templatesboolean: Let prompt switch the email to one of the workspace's published templates, which the answer names in template. Needs templates:read, and without it this is ignored.
body.filesboolean: Let prompt attach files the workspace holds, found by their name. The answer lists them in attach, each ready to send as { fileId: id }, and what matched no file in attachMissing. Needs files:read, and without it this is ignored.
body.withSubjectboolean: Also write a subject. The answer then carries subject.
body.draftstring: The body written so far, as text or Markdown, up to 20,000 characters. prompt then says what to change in it.
body.toArray<string>: Who it goes to.
body.ccArray<string>: Who is copied.
body.bccArray<string>: Who is blind copied.
body.sendEmailComposeSend: { scheduledAt?, tracking?, signature?, translate?, fromOptions?, encrypt? }, the send options as they stand. Give it, even {}, to let prompt change them. fromOptions lists up to 100 addresses it may go out as, so prompt can move it to one of them, and encrypt says whether it is encrypted end to end: give it only when every recipient can receive encrypted mail, so prompt can turn encryption on or off.
body.timeZonestring: The IANA time zone to read times in, such as Europe/Berlin. Without it, the time zone of the account.
body.threadIdstring: A thread to reply in, read as context.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Overrides the client's API key for this call only.

Returns

EmailCompositionResource, { object: 'composition', body, subject?, send?, template?, attach?, attachMissing?, note?, sources? }. Its send can name from, the address to send it from instead, one of send.fromOptions, and encrypt, whether to encrypt it end to end, when you gave send.encrypt. template, { id, name }, is the template to send it with instead, when you gave templates: true and prompt asked for one, and its body replaces body. attach lists the files to attach, each { id, filename, contentType, size } with size in bytes, when you gave files: true and prompt asked for them, and attachMissing what prompt asked to attach that matched no file, as prompt named it. note is a short sentence when part of prompt cannot be done this way, such as adding somebody whose address it was not given. sources lists the knowledge base items the draft drew on, when it used any, each { id, title, kind, scope, url }.

Example

const { body, subject, attach = [] } = await nextmail.emails.compose({    prompt: 'Send Ada the signed contract and ask for the invoice by Friday.',    from: 'billing@acme.com',    to: ['ada@example.com'],    withSubject: true,    files: true}) await nextmail.emails.send({    from: 'billing@acme.com',    to: ['ada@example.com'],    subject,    text: body,    attachments: attach.map(({ id }) => ({ fileId: id }))})

Notes

The SDK does not retry it, because a second call writes something different and spends a second AI action.
A server with no AI configured answers 409 ai_not_configured.

Also available in

API: POST /emails/compose
Python: emails.compose()
Ruby: emails.compose
PHP: emails->compose
Go: Emails.Compose
Java: emails().compose
C#: Emails.ComposeAsync
CLI: nextmail emails compose

`nextmail.emails.rewrite()`

Rewrite part of an email with AI

emails:send

Signature

rewrite(body: EmailRewrite, options?: RequestScope): Promise<EmailRewriteResource>

Rewrites a subject or a body and resolves different versions of it, as the rewrite menu of the composer does. action is shorten, lengthen, rephrase, formal, casual or custom, and custom needs instruction to say what to change, or the call is a 422 invalid_parameter on instruction. target is body, the default, or subject, and count asks for 1 to 5 versions, 3 by default.

Give threadId when the text is a reply, so the rewrite fits the conversation. That also needs threads:read. The versions never repeat the original and never add facts that are not in it.

Nothing is saved. Each call spends one of the workspace's AI actions.

Parameters

body.textstringRequired: The subject or body to rewrite.
body.actionRewriteActionRequired: What to do: shorten, lengthen, rephrase, formal, casual or custom.
body.targetRewriteTarget: body or subject. Defaults to body.
body.instructionstring: What to change, up to 500 characters. Required with custom.
body.countnumber: How many versions, 1 to 5. Defaults to 3.
body.threadIdstring: The thread the text replies in, read as context.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Overrides the client's API key for this call only.

Returns

EmailRewriteResource, { object: 'rewrite', target, variations }.

Example

const { variations } = await nextmail.emails.rewrite({    text: 'Hey, just checking whether you had a chance to look at the contract?',    action: 'formal'}) for (const version of variations) console.log(version)

Notes

The SDK does not retry it, because a second call spends a second AI action.
Fewer versions than count can come back when two of them turned out the same.

Also available in

API: POST /emails/rewrite
Python: emails.rewrite()
Ruby: emails.rewrite
PHP: emails->rewrite
Go: Emails.Rewrite
Java: emails().rewrite
C#: Emails.RewriteAsync
CLI: nextmail emails rewrite

`nextmail.emails.suggestSubject()`

Suggest a subject line

emails:send

Signature

suggestSubject(body: EmailSubject, options?: RequestScope): Promise<SubjectSuggestionResource>

Reads the body of an email and resolves a short subject for it, under 100 characters, in the style of the mail this workspace has sent, as the subject button of the composer does.

Nothing is saved. Each call spends one of the workspace's AI actions.

Parameters

body.messagestringRequired: The body of the email, as text or HTML.
options.signalAbortSignal: Cancels the request.
options.apiKeystring: Overrides the client's API key for this call only.

Returns

SubjectSuggestionResource, { object: 'subject_suggestion', subject }.

Example

const { subject } = await nextmail.emails.suggestSubject({    message: 'Thanks for the signed contract. Could you send the invoice by Friday?'}) console.log(subject)

Notes

The SDK does not retry it, because a second call spends a second AI action.

Also available in

API: POST /emails/subject
Python: emails.suggest_subject()
Ruby: emails.suggest_subject
PHP: emails->suggestSubject
Go: Emails.SuggestSubject
Java: emails().suggestSubject
C#: Emails.SuggestSubjectAsync
CLI: nextmail emails suggest-subject