Go SDK

Device and usage operations in SDK 2.1.1: all clients can request key-only device removal using tenant slug, key and activation ID. HTTP 204 confirms removal; protected portals still require OTP/account customer flows. Usage reporting returns boolean confirmation, supports nested/empty metadata objects and normalizes quantities below 1 to 1. Java/C++ use tryMeter/try_meter for that boolean contract and retain legacy detailed meter results. Neither operation retries automatically or uses offline cache. See this SDK's README for signatures and failure handling.

Floating sessions in SDK 2.1.1: checkout and heartbeat return a failed session without credentials on network/HTTP/parse failure (RequestFailed). Business denial preserves its error code or uses FloatingDenied. Floating never uses offline cache. The new boolean TryCheckin equivalent confirms HTTP 204; legacy checkin is best effort. Method names follow this language's conventions. See the source README and SDK availability matrix before choosing a registry version.

Go SDK

Pure Go 1.21+ client, standard library only — crypto/ecdsa handles offline token verification natively, so unlike SDKs built on OpenSSL/PHP-openssl/Python cryptography this needs no raw-signature-to-DER conversion step. No third-party packages at all.

License: the Go SDK source is MIT-licensed by permitcore. Keep its notice when redistributing. See the Go SDK license. Existing 2.1.1 module archives are immutable; an older archive without the file can use the repository notice. This does not change SDK behavior or license the hosted service.

Installation

Published as a real, tagged Go module — go get works directly, no manual setup:

SDK 2.1.1 uses the /v2 module path. Install it with this command.

go get github.com/permitCore-spec/permitcore-sdk-go/v2@v2.1.1

Or, to work from the source ZIP above instead (e.g. for local edits before a release), add a replace directive to your own go.mod pointing at the extracted folder:

require github.com/permitCore-spec/permitcore-sdk-go/v2 v2.1.1

replace github.com/permitCore-spec/permitcore-sdk-go/v2 => ./permitcore-sdk-go

Quick start — validate

import "github.com/permitCore-spec/permitcore-sdk-go/v2"

client := permitcore.New("https://api.permitcore.dev")
result := client.Validate("PERMIT-XXXX-XXXX-XXXX-XXXX", "",
	"7f3e9a2b-1c4d-4e8f-9a6b-3d2c1e0f5a8b") // expectedProductID — required trailing arg, pass "" to omit

if result.ErrorCode == "WrongProduct" {
	log.Fatalf("This key is for a different product: %s", result.ProductID)
}
if !result.IsValid {
	log.Fatalf("License invalid: %s", result.Message)
}

if result.HasFeature("export") {
	enableExport()
}

Activate (call once per installation)

result := client.Activate(
	"PERMIT-XXXX-XXXX-XXXX-XXXX",
	"",                   // deviceId — auto-generated HWID when empty
	"Production Server #1", // deviceName
	"",                   // version, optional
	"7f3e9a2b-1c4d-4e8f-9a6b-3d2c1e0f5a8b", // expectedProductID — required trailing arg, pass "" to omit
)
if result.ErrorCode == "WrongProduct" {
	log.Fatalf("Wrong product: %s", result.ProductID)
}
if !result.IsValid {
	log.Fatalf("Activation failed: %s", result.Message)
}
// Save result.IsValid to local storage — use Validate() on every subsequent launch.

Metered billing

// Record a single event
client.Meter(licenseKey, "api_call", 1, nil)

// Record bulk usage with metadata
client.Meter(licenseKey, "export", 5, map[string]any{"format": "pdf", "pages": 12})

Floating licenses

// Check out a seat at session start
session := client.Checkout(licenseKey, "", "")
if !session.Success {
	log.Fatalf("No seats available: %s", session.Message)
}
token := session.SessionToken

// Heartbeat every 4-5 minutes to keep the seat alive
client.Heartbeat(token)

// Release the seat when done
client.Checkin(token)

Offline grace period

result := client.Validate(licenseKey, "", "") // falls back to disk cache automatically (expectedProductID omitted here)

if result.IsOffline {
	// Running on cached result — server unreachable
	showNotice("Running offline. Connect to refresh your license.")
}

Offline license tokens

No extra package needed — crypto/ecdsa is standard library. Verification is pure local ECDSA P-256/SHA-256, zero network calls:

result := permitcore.VerifyOfflineToken(token, publicKeyBase64)

if result.IsValid {
	fmt.Println("Valid! Product:", result.Payload.ProductName)
}

// Bind to this device + persist locally (call once, e.g. at install time)
result = client.ActivateOffline(token, deviceID, productID)

// On every later launch — no token needed, reads the local cache
result = client.ValidateOffline(deviceID, productID)

LicenseResult reference

HasFeature(feature string) bool — case-insensitive check whether a feature flag is present on the license.

Product scoping: by default, any active key belonging to your tenant validates/activates successfully regardless of which product it was issued for. Both Validate and Activate take a trailing expectedProductID string argument (pass "" to omit) — set it and the server rejects a mismatch with ErrorCode == "WrongProduct". Find a product's ID in the Admin panel under Products.