---
title: "Changelog"
description: "Every release of the package, newest first."
url: "https://nextmail.sh/docs/go/changelog"
area: "Go"
category: "Reference"
---

# Changelog

Every release of the package, newest first.

## 0.0.1

The first release of the Go SDK: the module `github.com/bfzli/nextmail-go`, with the package `nextmail`. It needs Go 1.24 or later and nothing outside the standard library. It has a method for each of the 684 methods of the TypeScript SDK, in the same 53 namespaces and under the same names in Go’s casing, as fields of the client: `client.Emails.Send`, `client.Threads.List`, `client.Domains.Verify`. They cover everything from sending and reading mail to contacts, broadcasts, automations, the calendar, booking pages, tasks and the settings of a workspace, and a parity check proves that each one sends the same request as its TypeScript twin.

- `nextmail.New()` reads `NEXTMAIL_API_KEY`, `NEXTMAIL_ACCESS_TOKEN` and `NEXTMAIL_BASE_URL`, and takes `WithAPIKey`, `WithAccessToken`, `WithAccessTokenFunc`, `WithBaseURL`, `WithHTTPClient`, `WithTimeout`, `WithMaxRetries`, `WithUserAgent` and `WithHeader`. It never fails: a missing or malformed credential is reported by `client.Err()` and by the first call.
- Every method takes a `context.Context` first, which cancels the call or gives it a deadline. Request bodies are `nextmail.Body` maps that keep the field names of the API, options are functions such as `nextmail.WithLimit` and `nextmail.WithCursor`, and results are `nextmail.Object` values with readers such as `String`, `Int`, `Bool`, `Time` and `Object`.
- Every paginated resource has `List` for one page, `ListAll` for every item as a slice, and `Iterate`, which fetches the next page only when it gets there. Range over its `All()`, or call `Next`, `Item` and `Err` in a plain loop.
- Failures come back as `*nextmail.Error` values with `Status`, `Type`, `Code`, `Param`, `DocURL`, `RequestID`, `RetryAfter`, `Fields` and `Body`, and `errors.Is` matches them against sentinels such as `ErrNotFound`, `ErrValidation`, `ErrRateLimited`, `ErrStepUpRequired`, `ErrNetwork` and `ErrTimeout`. A mistake in the call itself matches `ErrInvalidArgument` and is returned before anything is sent.
- Reads, sends and every write that is safe to repeat are retried on 408, 500, 502, 503 and 504 with backoff, and on a 429 only when its `Retry-After` is a minute or less. Every send carries an idempotency key that its retries reuse, and `nextmail.WithIdempotencyKey` sets your own.
- An OAuth access token works in place of an API key, given as it is or by a function that runs before every request, so the token can be renewed without a new client. When a change made with a token needs a verification code, the error matches `ErrStepUpRequired`, and `client.Security.BeginStepUp` and `VerifyStepUp` provide one.
- `nextmail.VerifyWebhookSignature` checks a webhook delivery in constant time, refuses one more than five minutes old and returns the event.
- `nextmail.NewTempMail` builds a client for disposable inboxes that needs no credential, and `client.Request` calls an endpoint no method wraps, with the credential, timeout and retries of the client.
- `nextmail.ResolveLanguage`, `LanguageByCode`, `IsRTLLanguage`, `IsAPIKey`, `IsAccessToken` and `IsSealed` are the helpers of the TypeScript SDK, and the `constants` package holds the sets of values the API uses, such as webhook events, scopes and statuses.
- A client is safe for concurrent use. It sends a credential over plain `http:` only to a server on this machine, its default HTTP client follows no redirects, and printing a client, an option or an error never shows a credential.