Prepare the local backend convenience release

README.md

@@ -33,6 +33,9 @@ boundary and constraints that framework work must preserve.
 
 ## Release Guidance
 
+Consumers upgrading from `v0.2.0` to `v0.3.0` should read the
+[v0.3.0 changelog](docs/releases/v0.3.0.md).
+
 Consumers moving from `v0.1.0` to `v0.2.0` should read the
 [v0.2.0 changelog and migration guide](docs/releases/v0.2.0.md).
 

docs/consumers/pkg-promptkit.md

@@ -124,7 +124,7 @@ providers. The
 [`RunRequest` and `ExecutionTargetOverride` GoDoc](../../types.go) owns the
 exact normalization, precedence, error, copying, and exposure contract.
 
-### Register A Custom Backend
+### Configure A Local OpenAI-Compatible Endpoint
 
 Choose the smallest configuration that fits how the endpoint will be reused.
 

docs/releases/v0.2.0.md

@@ -90,7 +90,7 @@ engine, err := promptkit.NewEngine(
 ```
 
 See the
-[custom-backend consumer guide](../consumers/pkg-promptkit.md#register-a-custom-backend)
+[local-endpoint consumer guide](../consumers/pkg-promptkit.md#configure-a-local-openai-compatible-endpoint)
 for task-oriented usage. The
 [`Backend` and `WithBackend` GoDoc](../../backends.go) owns exact registration,
 validation, copying, defaulting, and uniqueness semantics. The

docs/releases/v0.3.0.md

@@ -0,0 +1,74 @@
+# Promptkit v0.3.0
+
+This supplemental changelog summarizes the consumer-facing changes from
+`v0.2.0` to `v0.3.0`. The annotated `v0.3.0` tag is the authoritative release
+record. Exact current contracts belong to the linked GoDoc and durable
+documentation.
+
+## Summary
+
+`v0.3.0` adds a concise way to register the common local OpenAI-compatible
+backend configuration:
+
+- `BackendLocal` provides the conventional, non-reserved backend ID `"local"`;
+  and
+- `LocalBackend` constructs an ordinary `Backend` from an endpoint and
+  concurrency limit.
+
+The helper is explicit and additive. It does not pre-register a backend, read
+environment variables, select a model, or replace the complete `Backend`
+configuration interface.
+
+## Compatibility
+
+Existing `v0.2.0` consumers require no migration. Endpoint-only profiles,
+complete custom `Backend` values, the built-in OpenRouter backend, and existing
+registrations using the literal ID `"local"` continue to work unchanged.
+
+## Upgrade
+
+Update the module dependency with:
+
+```sh
+go get gitea.maximumdirect.net/eric/promptkit@v0.3.0
+go mod tidy
+```
+
+Run the consuming project's ordinary tests and race-enabled tests after the
+upgrade.
+
+## Configure A Local Backend
+
+Register the convenience value through the existing `WithBackend` option and
+select it from one or more profiles:
+
+```go
+engine, err := promptkit.NewEngine(
+	promptkit.Config{PromptDir: "prompts"},
+	promptkit.WithBackend(
+		promptkit.LocalBackend("http://localhost:8000/v1", 2),
+	),
+	promptkit.WithProfiles(promptkit.Profile{
+		ID:        "local-summary",
+		BackendID: promptkit.BackendLocal,
+		Model:     "example-model",
+	}),
+)
+```
+
+Use an endpoint-only profile when shared backend identity and capacity policy
+are unnecessary. Continue to use a complete keyed `Backend` value for custom
+IDs, authentication, extra request parameters, explicit queue capacity, or
+multiple local endpoints.
+
+See the
+[local-endpoint consumer guide](../consumers/pkg-promptkit.md#configure-a-local-openai-compatible-endpoint)
+for task-oriented configuration choices. The
+[`BackendLocal`, `LocalBackend`, and `WithBackend` GoDoc](../../backends.go)
+owns their exact construction, registration, validation, and concurrency
+semantics.
+
+## Consumer Action
+
+None. Adopt the convenience constructor when it simplifies local endpoint
+configuration.

docs/roadmap/concurrency.md

@@ -11,7 +11,8 @@ consumer value, and important policy choices.
 This document is planning material, not a description of current behavior.
 Current exported contracts remain owned by Go declarations and GoDoc, backend
 registration guidance by the
-[consumer guide](../consumers/pkg-promptkit.md#register-a-custom-backend), and
+[consumer guide](../consumers/pkg-promptkit.md#configure-a-local-openai-compatible-endpoint),
+and
 implemented orchestration by the
 [internal runner document](../internal/runner.md).
 

public_contract_test.go

@@ -140,11 +140,18 @@ func TestUnknownProfileBackendHasProfileLoadIdentity(t *testing.T) {
 }
 
 func TestLocalBackendConstructsAndRegistersConventionalBackend(t *testing.T) {
-	const limit = 2
+	const (
+		localBackendID = "local"
+		limit          = 2
+	)
+	if promptkit.BackendLocal != localBackendID {
+		t.Fatalf("BackendLocal=%q, want %q", promptkit.BackendLocal, localBackendID)
+	}
+
 	endpoint := "http://local.example/v1"
 	backend := promptkit.LocalBackend(endpoint, limit)
 	want := promptkit.Backend{
-		ID:               promptkit.BackendLocal,
+		ID:               localBackendID,
 		Endpoint:         endpoint,
 		ConcurrencyLimit: limit,
 	}
@@ -157,7 +164,7 @@ func TestLocalBackendConstructsAndRegistersConventionalBackend(t *testing.T) {
 		promptkit.WithBackend(backend),
 		promptkit.WithProfiles(promptkit.Profile{
 			ID:        "local-profile",
-			BackendID: promptkit.BackendLocal,
+			BackendID: localBackendID,
 			Model:     "model",
 		}),
 	)
@@ -169,7 +176,7 @@ func TestLocalBackendConstructsAndRegistersConventionalBackend(t *testing.T) {
 	if err != nil {
 		t.Fatalf("prepare with local backend: %v", err)
 	}
-	if prepared.SelectedBackendID != promptkit.BackendLocal ||
+	if prepared.SelectedBackendID != localBackendID ||
 		prepared.EffectiveModelParams.Endpoint != endpoint {
 		t.Fatalf("unexpected local backend preparation: %+v", prepared)
 	}