go-postgrid

Unofficial Go client for the PostGrid print and mail and address verification APIs. Package postgrid (github.com/psyb0t/go-postgrid), generated with oapi-codegen, has typed methods for contacts, templates, letters, postcards, cheques, self mailers, campaigns, mailing lists, reports, webhooks and address verification, authenticated with an API key in the X-API-Key header. Use when Go code needs to send physical mail, manage PostGrid print and mail resources or verify addresses, or already imports go-postgrid.

Unofficial, typed Go client for PostGrid print and mail and address verification, in package postgrid at the module root.

Read references/setup.md for installation, operation groups, pagination and response handling. Inspect the generated method signatures before writing a call.

Security & safety

• Set X-API-Key through WithRequestEditorFn. Read the key from POSTGRID_API_KEY; never hardcode, commit or log it.
• Use https://api.postgrid.com. The spec has separate print and mail and address verification security schemes. Select the key for the API being called.
• Print and mail test or live behavior depends on the key. Use a test key while developing. Creating mail with a live key can send physical mail and incur charges.
• Create, send, cancel or delete resources only when the user requested that action. Do not retry mail creation after an uncertain response without checking whether the first request succeeded.

When to use

• Go code needs PostGrid contacts, templates, letters, postcards, cheques, self mailers, campaigns, mailing lists, reports or webhooks.
• Go code needs standard, international, batch or bulk address verification.
• The project already imports github.com/psyb0t/go-postgrid.

When NOT to use

• The code is not Go. This module ships only a Go package.
• A PostGrid-maintained client is required. This client is unofficial.
• The task changes the generated client itself. Read AGENTS.md in the repository.

Finding endpoints and types

The examples below cover a few calls. Every operation in the spec has a generated method, and the spec's descriptions are on them as Go doc comments. Look names and fields up instead of guessing. After go get github.com/psyb0t/go-postgrid, from inside your module:

bash

go doc github.com/psyb0t/go-postgrid ClientWithResponsesInterface  # every endpoint method
go doc github.com/psyb0t/go-postgrid ContactsListParams            # one method, params type or model
go doc -all github.com/psyb0t/go-postgrid                          # the whole package

The same documentation is at https://pkg.go.dev/github.com/psyb0t/go-postgrid.

Method names come from the spec's operation IDs. <OperationId>WithResponse takes the context, then the path parameters in order, then *<OperationId>Params when the operation has query or header parameters, then the request body when it has one. The JSON200 field (or JSON201 and so on, per declared status) holds the decoded body; it is nil for any other status. Operations that accept both JSON and multipart bodies have combined operation IDs and so longer names, such as LettersCreateJSONLettersCreateMultipartWithResponse.

Usage

go

import (
    "context"
    "net/http"
    "os"

    "github.com/psyb0t/go-postgrid"
)

auth := postgrid.WithRequestEditorFn(
    func(_ context.Context, req *http.Request) error {
        req.Header.Set("X-API-Key", os.Getenv("POSTGRID_API_KEY"))

        return nil
    },
)

client, err := postgrid.NewClientWithResponses(
    "https://api.postgrid.com",
    auth,
)
if err != nil {
    return err
}

res, err := client.ContactsListWithResponse(
    context.Background(),
    &postgrid.ContactsListParams{},
)
if err != nil {
    return err
}

_ = res.JSON200

Check StatusCode() and the status-specific response fields before consuming a response. The Go error covers transport and decoding failures; an HTTP error can return a nil Go error. Optional model fields may be pointers, so check them before dereferencing.

Finish by compiling the calling code and testing it against a local HTTP server. Tests must not create live mail or call PostGrid.