Move HTTP serving to the public engine

artifact_reader.go

@@ -0,0 +1,39 @@
+package scriptorium
+
+import (
+	"context"
+	"errors"
+
+	artifactadapter "gitea.maximumdirect.net/eric/scriptorium/internal/artifact"
+	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
+)
+
+var errNilArtifactReaderResponse = errors.New("artifact reader returned nil artifact without error")
+
+type publicArtifactReaderAdapter struct {
+	reader ArtifactReader
+}
+
+var _ artifactadapter.Reader = publicArtifactReaderAdapter{}
+
+func (a publicArtifactReaderAdapter) Read(ctx context.Context, ref domain.ArtifactRef) (*domain.Artifact, error) {
+	artifact, err := a.reader.Read(ctx, ArtifactRef{
+		Type: ArtifactRefType(ref.Type),
+		URI:  ref.URI,
+		Body: ref.Body,
+	})
+	if err != nil {
+		return nil, err
+	}
+	if artifact == nil {
+		return nil, errNilArtifactReaderResponse
+	}
+	return &domain.Artifact{
+		Name:        artifact.Name,
+		ContentType: artifact.ContentType,
+		Body:        copyBytes(artifact.Body),
+		URI:         artifact.URI,
+		Size:        artifact.Size,
+		Hash:        artifact.Hash,
+	}, nil
+}

artifact_reader_internal_test.go

@@ -0,0 +1,36 @@
+package scriptorium
+
+import (
+	"context"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
+)
+
+func TestPublicArtifactReaderAdapterCopiesBody(t *testing.T) {
+	reader := internalArtifactReaderFake{
+		artifact: &Artifact{Body: []byte("original")},
+	}
+	adapter := publicArtifactReaderAdapter{reader: &reader}
+
+	artifact, err := adapter.Read(context.Background(), domain.ArtifactRef{
+		Type: domain.ArtifactRefInline,
+		URI:  "memory://input",
+		Body: "input",
+	})
+	if err != nil {
+		t.Fatalf("read artifact: %v", err)
+	}
+	artifact.Body[0] = 'X'
+	if got := string(reader.artifact.Body); got != "original" {
+		t.Fatalf("reader artifact body was mutated: %q", got)
+	}
+}
+
+type internalArtifactReaderFake struct {
+	artifact *Artifact
+}
+
+func (r *internalArtifactReaderFake) Read(context.Context, ArtifactRef) (*Artifact, error) {
+	return r.artifact, nil
+}

docs/consumers/pkg-scriptorium.md

@@ -24,7 +24,8 @@ fields:
 | `HTTPClient` | Optional HTTP client for that built-in client. It is cloned; a positive `Timeout` on it is the transport cap and takes precedence over `Config.Timeout`. A non-positive client timeout is treated as unset. |
 
 Nil options are ignored. Invalid construction, including
-`WithLLMClient(nil)`, returns an error matching `ErrInvalidConfig`.
+`WithLLMClient(nil)` and `WithArtifactReader(nil)`, returns an error matching
+`ErrInvalidConfig`.
 
 Profile and request `timeout_seconds` values select a per-generation-call
 deadline independently of the transport cap. An explicit request override of
@@ -38,7 +39,8 @@ Source options replace their matching directory source:
 - profiles: `WithProfileFS(fsys, root)`, `WithProfileFile(path)`, and
   `WithProfiles(profiles...)`;
 - schemas: `WithSchemaFS(fsys, root)`, `WithSchemaFile(path)`; and
-- LLM client: `WithLLMClient(client)`.
+- LLM client: `WithLLMClient(client)`; and
+- artifact reader: `WithArtifactReader(reader)`.
 
 `fs.FS` prompt-content and schema paths stay inside their configured roots.
 Single-file prompt and profile sources are selected by their YAML `id`, not
@@ -109,6 +111,14 @@ The exported constants define these serialized values:
 counts. `RenderedPrompt`, `RenderedMessage`, `CacheControl`, and
 `StructuredOutputSpec` are the public shapes used by injected LLM clients.
 
+`ArtifactReader` implements
+`Read(context.Context, ArtifactRef) (*Artifact, error)`. Supplying it through
+`WithArtifactReader` replaces the engine's default inline and file reader for
+all inputs. Reader errors remain available through `errors.Is` alongside
+`ErrArtifactLoad`; a nil artifact with no error is treated as an artifact-load
+failure. Readers must supply artifact metadata and should not retain or mutate
+the caller's values.
+
 ## Requests, Inputs, And Overrides
 
 `RunRequest` fields are `PromptID`, `PromptVersion`, `ProfileID`,
@@ -172,8 +182,10 @@ Public methods preserve these sentinel checks through `errors.Is`:
 - `ErrInvalidRequest`
 - `ErrPromptNotFound`
 - `ErrProfileNotFound`
+- `ErrProfileRequired`
 - `ErrPromptLoad`
 - `ErrProfileLoad`
+- `ErrAPIKeyEnvMissing`
 - `ErrArtifactLoad`
 - `ErrPromptRender`
 - `ErrLLMGenerate`

docs/internal/sources.md

@@ -52,8 +52,12 @@ failures are operational errors.
 
 `internal/artifact` composes inline and file readers. The ordinary composite
 reader used by CLI and the public engine reads file references from the process
-filesystem. The restricted composite reader used by the HTTP adapter combines
-inline reading with a rooted file reader and optional byte limit.
+filesystem. `internal/adapter/http` provides the restricted public artifact
+reader for HTTP containment: it combines inline reading with a rooted file
+reader and optional byte limit. The existing internal restricted composite
+reader remains a temporary bridge for the current handler and serve wiring; it
+does not define the HTTP reader's long-term boundary or carry a compatibility
+promise.
 
 The rooted reader cleans paths and applies lexical containment without resolving
 symlinks. It checks relative references against the configured root and accepts
@@ -80,6 +84,7 @@ Inspect:
 - `internal/profile/repository_test.go`
 - `internal/profile/builtin/repository_test.go`
 - `internal/artifact/reader_test.go`
+- `internal/adapter/http/artifact_reader_test.go`
 - `internal/validate/standard_validator_test.go`
 - `internal/usecase/integration_test.go`
 - `engine_test.go`

engine.go

@@ -26,15 +26,17 @@ import (
 var ErrInvalidConfig = errors.New("invalid engine configuration")
 
 var (
-	ErrInvalidRequest  = errors.New("invalid run request")
-	ErrPromptNotFound  = errors.New("prompt not found")
-	ErrProfileNotFound = errors.New("profile not found")
-	ErrPromptLoad      = errors.New("failed to load prompt definition")
-	ErrProfileLoad     = errors.New("failed to load execution profile")
-	ErrArtifactLoad    = errors.New("failed to load artifact")
-	ErrPromptRender    = errors.New("failed to render prompt")
-	ErrLLMGenerate     = errors.New("failed to generate output")
-	ErrValidation      = errors.New("failed to validate output")
+	ErrInvalidRequest   = errors.New("invalid run request")
+	ErrPromptNotFound   = errors.New("prompt not found")
+	ErrProfileNotFound  = errors.New("profile not found")
+	ErrProfileRequired  = errors.New("profile selection is required")
+	ErrPromptLoad       = errors.New("failed to load prompt definition")
+	ErrProfileLoad      = errors.New("failed to load execution profile")
+	ErrAPIKeyEnvMissing = errors.New("api_key_env points to an unset environment variable")
+	ErrArtifactLoad     = errors.New("failed to load artifact")
+	ErrPromptRender     = errors.New("failed to render prompt")
+	ErrLLMGenerate      = errors.New("failed to generate output")
+	ErrValidation       = errors.New("failed to validate output")
 )
 
 // Engine prepares and runs Scriptorium prompt requests.
@@ -68,6 +70,7 @@ func (f optionFunc) apply(options *engineOptions) error {
 
 type engineOptions struct {
 	llmClient       llm.Client
+	artifactReader  artifactadapter.Reader
 	promptDefs      promptdef.Repository
 	profiles        profile.Repository
 	memoryProfiles  profile.Repository
@@ -76,6 +79,7 @@ type engineOptions struct {
 	profileSource   bool
 	memorySource    bool
 	validatorSource bool
+	artifactSource  bool
 }
 
 // WithLLMClient injects a custom LLM client for execution.
@@ -89,6 +93,18 @@ func WithLLMClient(client LLMClient) Option {
 	})
 }
 
+// WithArtifactReader injects a reader for every input artifact reference.
+func WithArtifactReader(reader ArtifactReader) Option {
+	return optionFunc(func(options *engineOptions) error {
+		if reader == nil {
+			return ErrInvalidConfig
+		}
+		options.artifactReader = publicArtifactReaderAdapter{reader: reader}
+		options.artifactSource = true
+		return nil
+	})
+}
+
 // WithPromptFS loads prompt definitions from fsys under root.
 //
 // The source uses the same strict prompt YAML rules as configured prompt
@@ -253,11 +269,16 @@ func NewEngine(cfg Config, opts ...Option) (*Engine, error) {
 		}
 	}
 
+	artifacts := options.artifactReader
+	if !options.artifactSource {
+		artifacts = artifactadapter.NewCompositeReader()
+	}
+
 	return &Engine{
 		runner: usecase.NewRunner(
 			promptDefs,
 			profiles,
-			artifactadapter.NewCompositeReader(),
+			artifacts,
 			prompt.NewGoRenderer(),
 			llmClient,
 			validator,

engine_test.go

@@ -835,11 +835,132 @@ func TestMissingCredentialsFailClearlyWhenProfileRequiresAuth(t *testing.T) {
 	if !errors.Is(err, scriptorium.ErrInvalidRequest) {
 		t.Fatalf("expected invalid request for missing credentials, got %v", err)
 	}
+	if !errors.Is(err, scriptorium.ErrAPIKeyEnvMissing) {
+		t.Fatalf("expected missing credential environment error, got %v", err)
+	}
 	if err == nil || !strings.Contains(err.Error(), missingEnv) {
 		t.Fatalf("expected missing env name in error, got %v", err)
 	}
 }
 
+func TestWithArtifactReaderRejectsNilReader(t *testing.T) {
+	_, err := scriptorium.NewEngine(contractConfig(frameworkSchemaDir), scriptorium.WithArtifactReader(nil))
+	if !errors.Is(err, scriptorium.ErrInvalidConfig) {
+		t.Fatalf("expected ErrInvalidConfig, got %v", err)
+	}
+}
+
+func TestArtifactReaderReceivesPublicReferenceAndPreparesArtifact(t *testing.T) {
+	reader := &recordingArtifactReader{
+		artifact: &scriptorium.Artifact{
+			ContentType: "text/plain",
+			Body:        []byte("Reader-supplied transcript."),
+			URI:         "reader://transcript",
+			Size:        int64(len("Reader-supplied transcript.")),
+			Hash:        "reader-transcript-hash",
+		},
+	}
+	engine := newArtifactReaderEngine(t, reader)
+
+	ref := scriptorium.ArtifactRef{
+		Type: scriptorium.ArtifactRefInline,
+		URI:  "reader://transcript",
+		Body: "request body",
+	}
+	prepared, err := engine.Prepare(context.Background(), scriptorium.RunRequest{
+		PromptID: "artifact-reader",
+		Inputs: map[string]scriptorium.ArtifactRef{
+			"transcript": ref,
+		},
+	})
+	if err != nil {
+		t.Fatalf("prepare with artifact reader: %v", err)
+	}
+	if len(reader.refs) != 1 || !reflect.DeepEqual(reader.refs[0], ref) {
+		t.Fatalf("reader received %#v, want %#v", reader.refs, ref)
+	}
+	if prepared.InputHashes["transcript"] != "reader-transcript-hash" {
+		t.Fatalf("unexpected input hash: %#v", prepared.InputHashes)
+	}
+	if len(prepared.Messages) != 1 || !strings.Contains(prepared.Messages[0].Content, "Reader-supplied transcript.") {
+		t.Fatalf("prepared prompt omitted reader artifact: %#v", prepared.Messages)
+	}
+}
+
+func TestArtifactReaderFailuresPreserveArtifactLoadErrors(t *testing.T) {
+	readerErr := errors.New("artifact reader failed")
+
+	tests := []struct {
+		name       string
+		ctx        context.Context
+		reader     *recordingArtifactReader
+		wantNested error
+	}{
+		{
+			name:       "reader error",
+			ctx:        context.Background(),
+			reader:     &recordingArtifactReader{err: readerErr},
+			wantNested: readerErr,
+		},
+		{
+			name:   "nil artifact",
+			ctx:    context.Background(),
+			reader: &recordingArtifactReader{},
+		},
+		{
+			name: "reader cancellation",
+			ctx:  context.Background(),
+			reader: &recordingArtifactReader{read: func(context.Context, scriptorium.ArtifactRef) (*scriptorium.Artifact, error) {
+				return nil, context.Canceled
+			}},
+			wantNested: context.Canceled,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			engine := newArtifactReaderEngine(t, tc.reader)
+			_, err := engine.Prepare(tc.ctx, scriptorium.RunRequest{
+				PromptID: "artifact-reader",
+				Inputs: map[string]scriptorium.ArtifactRef{
+					"transcript": scriptorium.Inline("input"),
+				},
+			})
+			if !errors.Is(err, scriptorium.ErrArtifactLoad) {
+				t.Fatalf("expected ErrArtifactLoad, got %v", err)
+			}
+			if tc.wantNested != nil && !errors.Is(err, tc.wantNested) {
+				t.Fatalf("expected nested %v, got %v", tc.wantNested, err)
+			}
+		})
+	}
+}
+
+func TestPrepareWithoutProfileMatchesSpecificPublicError(t *testing.T) {
+	promptDir := t.TempDir()
+	writePublicPromptFile(t, promptDir, "profile-required", "")
+	engine, err := scriptorium.NewEngine(scriptorium.Config{
+		PromptDir: promptDir,
+		SchemaDir: frameworkSchemaDir,
+	})
+	if err != nil {
+		t.Fatalf("construct engine: %v", err)
+	}
+
+	_, err = engine.Prepare(context.Background(), scriptorium.RunRequest{
+		PromptID: "profile-required",
+		Inputs: map[string]scriptorium.ArtifactRef{
+			"transcript": scriptorium.Inline("input"),
+		},
+	})
+	if !errors.Is(err, scriptorium.ErrInvalidRequest) {
+		t.Fatalf("expected ErrInvalidRequest, got %v", err)
+	}
+	if !errors.Is(err, scriptorium.ErrProfileRequired) {
+		t.Fatalf("expected ErrProfileRequired, got %v", err)
+	}
+}
+
 func TestRunValidationFailureReturnsResult(t *testing.T) {
 	fake := &fakeLLMClient{
 		response: &scriptorium.GenerateResponse{Content: ""},
@@ -2207,6 +2328,22 @@ func newContractEngineWithOptions(t *testing.T, schemaDir string, opts ...script
 	return engine
 }
 
+func newArtifactReaderEngine(t *testing.T, reader scriptorium.ArtifactReader) *scriptorium.Engine {
+	t.Helper()
+
+	promptDir := t.TempDir()
+	writePublicPromptFile(t, promptDir, "artifact-reader", frameworkFastProfileID)
+	engine, err := scriptorium.NewEngine(scriptorium.Config{
+		PromptDir:  promptDir,
+		ProfileDir: frameworkProfileDir,
+		SchemaDir:  frameworkSchemaDir,
+	}, scriptorium.WithArtifactReader(reader))
+	if err != nil {
+		t.Fatalf("construct engine with artifact reader: %v", err)
+	}
+	return engine
+}
+
 func contractConfig(schemaDir string) scriptorium.Config {
 	return scriptorium.Config{
 		PromptDir:  frameworkPromptDir,
@@ -2363,6 +2500,24 @@ type fakeLLMClient struct {
 	requests []scriptorium.GenerateRequest
 }
 
+type recordingArtifactReader struct {
+	artifact *scriptorium.Artifact
+	err      error
+	refs     []scriptorium.ArtifactRef
+	read     func(context.Context, scriptorium.ArtifactRef) (*scriptorium.Artifact, error)
+}
+
+func (r *recordingArtifactReader) Read(ctx context.Context, ref scriptorium.ArtifactRef) (*scriptorium.Artifact, error) {
+	r.refs = append(r.refs, ref)
+	if r.read != nil {
+		return r.read(ctx, ref)
+	}
+	if r.err != nil {
+		return nil, r.err
+	}
+	return r.artifact, nil
+}
+
 type roundTripFunc func(*http.Request) (*http.Response, error)
 
 func (f roundTripFunc) RoundTrip(req *http.Request) (*http.Response, error) {

errors.go

@@ -29,8 +29,10 @@ func hasPublicError(err error) bool {
 		ErrInvalidRequest,
 		ErrPromptNotFound,
 		ErrProfileNotFound,
+		ErrProfileRequired,
 		ErrPromptLoad,
 		ErrProfileLoad,
+		ErrAPIKeyEnvMissing,
 		ErrArtifactLoad,
 		ErrPromptRender,
 		ErrLLMGenerate,
@@ -49,6 +51,8 @@ func publicErrorFor(err error) error {
 		return ErrPromptNotFound
 	case errors.Is(err, profile.ErrProfileNotFound):
 		return ErrProfileNotFound
+	case errors.Is(err, usecase.ErrProfileRequired):
+		return errors.Join(ErrInvalidRequest, ErrProfileRequired)
 	case errors.Is(err, usecase.ErrPromptLoad):
 		return ErrPromptLoad
 	case errors.Is(err, usecase.ErrProfileLoad):
@@ -57,6 +61,8 @@ func publicErrorFor(err error) error {
 		return ErrPromptLoad
 	case isProfileLoadCause(err):
 		return ErrProfileLoad
+	case errors.Is(err, usecase.ErrAPIKeyEnvMissing):
+		return errors.Join(ErrInvalidRequest, ErrAPIKeyEnvMissing)
 	case errors.Is(err, usecase.ErrArtifactLoad):
 		return ErrArtifactLoad
 	case errors.Is(err, usecase.ErrPromptRender):

internal/adapter/cli/run.go

@@ -12,18 +12,11 @@ import (
 	"strings"
 	"time"
 
+	"gitea.maximumdirect.net/eric/scriptorium"
 	httpadapter "gitea.maximumdirect.net/eric/scriptorium/internal/adapter/http"
-	artifactadapter "gitea.maximumdirect.net/eric/scriptorium/internal/artifact"
 	appconfig "gitea.maximumdirect.net/eric/scriptorium/internal/config"
 	"gitea.maximumdirect.net/eric/scriptorium/internal/defaults"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
 	renderformat "gitea.maximumdirect.net/eric/scriptorium/internal/format"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/llm"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/profile/builtin"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/prompt"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/promptdef"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/usecase"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/validate"
 )
 
 const (
@@ -140,15 +133,13 @@ func runCommand(args []string, stdout, stderr io.Writer) int {
 		return ExitRuntimeError
 	}
 
-	llmClient, err := newOpenAIClient()
+	engine, err := newEngine(cfg)
 	if err != nil {
-		fmt.Fprintf(stderr, "llm client error: %v\n", err)
+		fmt.Fprintf(stderr, "engine error: %v\n", err)
 		return ExitRuntimeError
 	}
 
-	runner := newRunner(cfg.promptDir, cfg.profileDir, cfg.schemaDir, llmClient)
-
-	res, runErr := runner.Run(context.Background(), req)
+	res, runErr := engine.Run(context.Background(), req)
 	if runErr != nil {
 		fmt.Fprintf(stderr, "run error: %v\n", runErr)
 		return ExitRuntimeError
@@ -176,9 +167,13 @@ func renderCommand(args []string, stdout, stderr io.Writer) int {
 		return ExitRuntimeError
 	}
 
-	runner := newRunner(cfg.promptDir, cfg.profileDir, cfg.schemaDir, nil)
+	engine, err := newEngine(&cfg.runConfig)
+	if err != nil {
+		fmt.Fprintf(stderr, "engine error: %v\n", err)
+		return ExitRuntimeError
+	}
 
-	prepared, prepErr := runner.Prepare(context.Background(), req)
+	prepared, prepErr := engine.Prepare(context.Background(), req)
 	if prepErr != nil {
 		fmt.Fprintf(stderr, "render error: %v\n", prepErr)
 		return ExitRuntimeError
@@ -204,21 +199,23 @@ func serveCommand(args []string, stderr io.Writer) int {
 		return ExitRuntimeError
 	}
 
-	llmClient, err := newOpenAIClient()
-	if err != nil {
-		fmt.Fprintf(stderr, "llm client error: %v\n", err)
-		return ExitRuntimeError
-	}
-
-	artifactReader, err := artifactadapter.NewRestrictedCompositeReaderWithLimit(cfg.artifactRoot, cfg.maxArtifactBytes)
+	artifactReader, err := httpadapter.NewRestrictedArtifactReader(cfg.artifactRoot, cfg.maxArtifactBytes)
 	if err != nil {
 		fmt.Fprintf(stderr, "artifact root error: %v\n", err)
 		return ExitRuntimeError
 	}
 
-	runner := newRunnerWithArtifactReader(cfg.promptDir, cfg.profileDir, cfg.schemaDir, llmClient, artifactReader)
+	engine, err := newEngine(&runConfig{
+		promptDir:  cfg.promptDir,
+		profileDir: cfg.profileDir,
+		schemaDir:  cfg.schemaDir,
+	}, scriptorium.WithArtifactReader(artifactReader))
+	if err != nil {
+		fmt.Fprintf(stderr, "engine error: %v\n", err)
+		return ExitRuntimeError
+	}
 
-	h := httpadapter.NewHandlerWithOptions(runner, httpadapter.HandlerOptions{
+	h := httpadapter.NewHandlerWithOptions(engine, httpadapter.HandlerOptions{
 		MaxRequestBytes:  cfg.maxRequestBytes,
 		MaxResponseBytes: cfg.maxResponseBytes,
 	})
@@ -541,52 +538,36 @@ func validateRequiredLibraryDirs(promptDir string) error {
 	return nil
 }
 
-func newRunner(promptDir, profileDir, schemaDir string, llmClient llm.Client) *usecase.Runner {
-	return newRunnerWithArtifactReader(promptDir, profileDir, schemaDir, llmClient, artifactadapter.NewCompositeReader())
+func newEngine(cfg *runConfig, options ...scriptorium.Option) (*scriptorium.Engine, error) {
+	return scriptorium.NewEngine(scriptorium.Config{
+		PromptDir:  cfg.promptDir,
+		ProfileDir: cfg.profileDir,
+		SchemaDir:  cfg.schemaDir,
+	}, options...)
 }
 
-func newRunnerWithArtifactReader(promptDir, profileDir, schemaDir string, llmClient llm.Client, artifactReader artifactadapter.Reader) *usecase.Runner {
-	if artifactReader == nil {
-		artifactReader = artifactadapter.NewCompositeReader()
-	}
-	return usecase.NewRunner(
-		promptdef.NewFilesystemRepository(promptDir),
-		builtin.NewRepositoryWithDirectory(profileDir),
-		artifactReader,
-		prompt.NewGoRenderer(),
-		llmClient,
-		validate.NewStandardValidator(schemaDir),
-	)
-}
-
-func newOpenAIClient() (*llm.OpenAICompatibleClient, error) {
-	return llm.NewOpenAICompatibleClient(llm.OpenAICompatibleConfig{
-		Timeout: defaults.LLMRequestTimeoutDefault,
-	})
-}
-
-func buildRunRequestFromConfig(cfg *runConfig) (domain.RunRequest, error) {
+func buildRunRequestFromConfig(cfg *runConfig) (scriptorium.RunRequest, error) {
 	inputMappings, err := parseMappings(cfg.inputRaw, false)
 	if err != nil {
-		return domain.RunRequest{}, fmt.Errorf("input parse error: %w", err)
+		return scriptorium.RunRequest{}, fmt.Errorf("input parse error: %w", err)
 	}
 
 	varMappings := map[string]string{}
 	if len(cfg.varRaw) > 0 {
 		varMappings, err = parseMappings(cfg.varRaw, false)
 		if err != nil {
-			return domain.RunRequest{}, fmt.Errorf("var parse error: %w", err)
+			return scriptorium.RunRequest{}, fmt.Errorf("var parse error: %w", err)
 		}
 	}
 
-	inputs := make(map[string]domain.ArtifactRef, len(inputMappings))
+	inputs := make(map[string]scriptorium.ArtifactRef, len(inputMappings))
 	for name, path := range inputMappings {
-		inputs[name] = domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: path}
+		inputs[name] = scriptorium.File(path)
 	}
 
-	var modelOverride *domain.ExecutionTargetOverride
+	var modelOverride *scriptorium.ExecutionTargetOverride
 	if cfg.llmBaseURLSet || cfg.modelSet || cfg.temperatureSet || cfg.maxTokensSet || cfg.topPSet || cfg.apiKeyEnvSet || cfg.timeoutSet {
-		modelOverride = &domain.ExecutionTargetOverride{
+		modelOverride = &scriptorium.ExecutionTargetOverride{
 			Endpoint:  cfg.llmBaseURL,
 			Model:     cfg.model,
 			APIKeyEnv: cfg.apiKeyEnv,
@@ -606,7 +587,7 @@ func buildRunRequestFromConfig(cfg *runConfig) (domain.RunRequest, error) {
 		}
 	}
 
-	return domain.RunRequest{
+	return scriptorium.RunRequest{
 		PromptID:  cfg.promptID,
 		ProfileID: cfg.profileID,
 		Inputs:    inputs,
@@ -670,17 +651,17 @@ func writeOutput(stdout io.Writer, outputPath string, body []byte) error {
 	return os.WriteFile(outputPath, body, 0644)
 }
 
-func determineExitCode(runErr error, result *domain.RunResult) int {
+func determineExitCode(runErr error, result *scriptorium.RunResult) int {
 	if runErr != nil {
 		return ExitRuntimeError
 	}
-	if result != nil && result.Validation.Status == domain.ValidationFailed {
+	if result != nil && result.Validation.Status == scriptorium.ValidationFailed {
 		return ExitValidationFailed
 	}
 	return ExitOK
 }
 
-func printSummary(stderr io.Writer, res *domain.RunResult) {
+func printSummary(stderr io.Writer, res *scriptorium.RunResult) {
 	if res == nil {
 		return
 	}

internal/adapter/cli/run_test.go

@@ -17,9 +17,9 @@ import (
 	"testing"
 	"time"
 
+	"gitea.maximumdirect.net/eric/scriptorium"
 	appconfig "gitea.maximumdirect.net/eric/scriptorium/internal/config"
 	"gitea.maximumdirect.net/eric/scriptorium/internal/defaults"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
 	renderformat "gitea.maximumdirect.net/eric/scriptorium/internal/format"
 )
 
@@ -655,6 +655,40 @@ func TestRunAndRenderBuildEquivalentRuntimeOverrideRequestsForSharedFlags(t *tes
 	}
 }
 
+func TestBuildRunRequestPreservesNumericOverridePresence(t *testing.T) {
+	omitted, err := buildRunRequestFromConfig(&runConfig{
+		promptID: "prompt-1",
+		inputRaw: []string{"transcript=./transcript.md"},
+	})
+	if err != nil {
+		t.Fatalf("expected omitted override request to build, got %v", err)
+	}
+	if omitted.Execution != nil {
+		t.Fatalf("expected omitted numeric flags to leave execution override nil, got %#v", omitted.Execution)
+	}
+
+	explicitZeros, err := buildRunRequestFromConfig(&runConfig{
+		promptID:       "prompt-1",
+		inputRaw:       []string{"transcript=./transcript.md"},
+		temperatureSet: true,
+		maxTokensSet:   true,
+		topPSet:        true,
+		timeoutSet:     true,
+	})
+	if err != nil {
+		t.Fatalf("expected explicit zero override request to build, got %v", err)
+	}
+	if explicitZeros.Execution == nil {
+		t.Fatal("expected explicit numeric flags to create execution override")
+	}
+	if explicitZeros.Execution.Temperature == nil || explicitZeros.Execution.MaxTokens == nil || explicitZeros.Execution.TopP == nil || explicitZeros.Execution.TimeoutSeconds == nil {
+		t.Fatalf("expected explicit zero numeric overrides to remain non-nil, got %#v", explicitZeros.Execution)
+	}
+	if *explicitZeros.Execution.Temperature != 0 || *explicitZeros.Execution.MaxTokens != 0 || *explicitZeros.Execution.TopP != 0 || *explicitZeros.Execution.TimeoutSeconds != 0 {
+		t.Fatalf("expected explicit numeric overrides to retain zero values, got %#v", explicitZeros.Execution)
+	}
+}
+
 func TestParseRunArgsFailsClearlyWhenNoEffectivePromptDir(t *testing.T) {
 	configPath := writeAppConfigFile(t, `
 profile_dir: ./profiles
@@ -731,13 +765,13 @@ func TestDetermineExitCode(t *testing.T) {
 	if got := determineExitCode(errors.New("boom"), nil); got != ExitRuntimeError {
 		t.Fatalf("expected runtime exit code, got %d", got)
 	}
-	if got := determineExitCode(nil, &domain.RunResult{Validation: domain.ValidationResult{Status: domain.ValidationFailed}}); got != ExitValidationFailed {
+	if got := determineExitCode(nil, &scriptorium.RunResult{Validation: scriptorium.ValidationResult{Status: scriptorium.ValidationFailed}}); got != ExitValidationFailed {
 		t.Fatalf("expected validation exit code, got %d", got)
 	}
-	if got := determineExitCode(nil, &domain.RunResult{Validation: domain.ValidationResult{Status: domain.ValidationPassed}}); got != ExitOK {
+	if got := determineExitCode(nil, &scriptorium.RunResult{Validation: scriptorium.ValidationResult{Status: scriptorium.ValidationPassed}}); got != ExitOK {
 		t.Fatalf("expected success exit code for passed validation, got %d", got)
 	}
-	if got := determineExitCode(nil, &domain.RunResult{Validation: domain.ValidationResult{Status: domain.ValidationSkipped}}); got != ExitOK {
+	if got := determineExitCode(nil, &scriptorium.RunResult{Validation: scriptorium.ValidationResult{Status: scriptorium.ValidationSkipped}}); got != ExitOK {
 		t.Fatalf("expected success exit code for skipped validation, got %d", got)
 	}
 }
@@ -1208,12 +1242,12 @@ func TestWriteOutputAndSummaryUseSeparateWriters(t *testing.T) {
 	if err := writeOutput(&stdout, "", []byte("artifact-body")); err != nil {
 		t.Fatalf("unexpected writeOutput error: %v", err)
 	}
-	printSummary(&stderr, &domain.RunResult{
+	printSummary(&stderr, &scriptorium.RunResult{
 		PromptID:           "p",
 		PromptVersion:      "1",
 		SelectedProfileID:  "exec",
 		ModelName:          "m",
-		Validation:         domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic},
+		Validation:         scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic},
 		RenderedPromptHash: "h",
 		InputHashes:        map[string]string{"in": "x"},
 	})
@@ -1232,15 +1266,15 @@ func TestWriteOutputAndSummaryUseSeparateWriters(t *testing.T) {
 func TestPrintSummaryIncludesCacheUsageWhenPresent(t *testing.T) {
 	var stderr bytes.Buffer
 
-	printSummary(&stderr, &domain.RunResult{
+	printSummary(&stderr, &scriptorium.RunResult{
 		PromptID:           "p",
 		PromptVersion:      "1",
 		SelectedProfileID:  "exec",
 		ModelName:          "m",
-		Validation:         domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic},
+		Validation:         scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic},
 		RenderedPromptHash: "h",
 		InputHashes:        map[string]string{"in": "x"},
-		Usage: domain.TokenUsage{
+		Usage: scriptorium.TokenUsage{
 			PromptTokens:     10,
 			CompletionTokens: 5,
 			TotalTokens:      15,

internal/adapter/http/artifact_reader.go

@@ -0,0 +1,165 @@
+package httpadapter
+
+import (
+	"context"
+	"crypto/sha256"
+	"errors"
+	"fmt"
+	"io"
+	"mime"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/scriptorium"
+)
+
+var (
+	ErrFileNotAllowed  = errors.New("file artifact references are not allowed")
+	ErrFileOutsideRoot = errors.New("file artifact path is outside artifact root")
+	ErrFileTooLarge    = errors.New("file artifact exceeds size limit")
+)
+
+const fallbackArtifactContentType = "text/plain"
+
+// NewRestrictedArtifactReader creates the HTTP artifact reader for a rooted
+// filesystem and optional byte limit. An empty root permits inline artifacts
+// but denies file references; a zero limit permits artifacts of any size.
+func NewRestrictedArtifactReader(root string, maxBytes int64) (scriptorium.ArtifactReader, error) {
+	if maxBytes < 0 {
+		return nil, fmt.Errorf("artifact size limit must be greater than or equal to 0")
+	}
+
+	cleanRoot := strings.TrimSpace(root)
+	if cleanRoot == "" {
+		return &restrictedArtifactReader{maxBytes: maxBytes}, nil
+	}
+	absRoot, err := filepath.Abs(filepath.Clean(cleanRoot))
+	if err != nil {
+		return nil, fmt.Errorf("resolve artifact root: %w", err)
+	}
+	return &restrictedArtifactReader{root: absRoot, maxBytes: maxBytes}, nil
+}
+
+type restrictedArtifactReader struct {
+	root     string
+	maxBytes int64
+}
+
+var _ scriptorium.ArtifactReader = (*restrictedArtifactReader)(nil)
+
+func (r *restrictedArtifactReader) Read(ctx context.Context, ref scriptorium.ArtifactRef) (*scriptorium.Artifact, error) {
+	select {
+	case <-ctx.Done():
+		return nil, ctx.Err()
+	default:
+	}
+
+	switch ref.Type {
+	case scriptorium.ArtifactRefInline:
+		return readInlineArtifact(ref)
+	case scriptorium.ArtifactRefFile:
+		return r.readFileArtifact(ref)
+	default:
+		return nil, fmt.Errorf("unsupported artifact reference type %q", ref.Type)
+	}
+}
+
+func readInlineArtifact(ref scriptorium.ArtifactRef) (*scriptorium.Artifact, error) {
+	if ref.Body == "" {
+		return nil, errors.New("inline artifact body is required")
+	}
+
+	body := []byte(ref.Body)
+	return &scriptorium.Artifact{
+		ContentType: fallbackArtifactContentType,
+		Body:        body,
+		Size:        int64(len(body)),
+		Hash:        artifactHash(body),
+		URI:         ref.URI,
+	}, nil
+}
+
+func (r *restrictedArtifactReader) readFileArtifact(ref scriptorium.ArtifactRef) (*scriptorium.Artifact, error) {
+	if ref.URI == "" {
+		return nil, errors.New("file artifact path is required")
+	}
+	if r.root == "" {
+		return nil, ErrFileNotAllowed
+	}
+
+	path, err := r.resolveLexicalPath(ref.URI)
+	if err != nil {
+		return nil, err
+	}
+	return readArtifactFile(path, r.maxBytes)
+}
+
+// resolveLexicalPath checks cleaned path containment without resolving symlinks.
+func (r *restrictedArtifactReader) resolveLexicalPath(rawPath string) (string, error) {
+	cleanPath := filepath.Clean(strings.TrimSpace(rawPath))
+	candidate := cleanPath
+	if !filepath.IsAbs(cleanPath) {
+		candidate = filepath.Join(r.root, cleanPath)
+	}
+
+	absCandidate, err := filepath.Abs(candidate)
+	if err != nil {
+		return "", fmt.Errorf("resolve artifact path: %w", err)
+	}
+	absCandidate = filepath.Clean(absCandidate)
+
+	rel, err := filepath.Rel(r.root, absCandidate)
+	if err != nil {
+		return "", fmt.Errorf("compare artifact path to root: %w", err)
+	}
+	if rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) || filepath.IsAbs(rel) {
+		return "", ErrFileOutsideRoot
+	}
+	return absCandidate, nil
+}
+
+func readArtifactFile(path string, maxBytes int64) (*scriptorium.Artifact, error) {
+	file, err := os.Open(path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read file %s: %w", path, err)
+	}
+	defer file.Close()
+
+	info, err := file.Stat()
+	if err != nil {
+		return nil, fmt.Errorf("failed to stat file %s: %w", path, err)
+	}
+	if maxBytes > 0 && info.Size() > maxBytes {
+		return nil, ErrFileTooLarge
+	}
+
+	var reader io.Reader = file
+	if maxBytes > 0 {
+		reader = io.LimitReader(file, maxBytes+1)
+	}
+	body, err := io.ReadAll(reader)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read file %s: %w", path, err)
+	}
+	if maxBytes > 0 && int64(len(body)) > maxBytes {
+		return nil, ErrFileTooLarge
+	}
+
+	contentType := mime.TypeByExtension(filepath.Ext(path))
+	if contentType == "" {
+		contentType = fallbackArtifactContentType
+	}
+	return &scriptorium.Artifact{
+		Name:        filepath.Base(path),
+		ContentType: contentType,
+		Body:        body,
+		URI:         path,
+		Size:        int64(len(body)),
+		Hash:        artifactHash(body),
+	}, nil
+}
+
+func artifactHash(body []byte) string {
+	return fmt.Sprintf("%x", sha256.Sum256(body))
+}

internal/adapter/http/artifact_reader_test.go

@@ -0,0 +1,181 @@
+package httpadapter
+
+import (
+	"context"
+	"errors"
+	"mime"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/scriptorium"
+)
+
+func TestRestrictedArtifactReaderReadsContainedFiles(t *testing.T) {
+	root := t.TempDir()
+	outside := t.TempDir()
+	inputPath := filepath.Join(root, "input.md")
+	if err := os.WriteFile(inputPath, []byte("allowed"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(root, "input.unknown"), []byte("unknown type"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Mkdir(filepath.Join(root, "nested"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(outside, "secret.txt"), []byte("denied"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	reader, err := NewRestrictedArtifactReader(root, 0)
+	if err != nil {
+		t.Fatalf("construct restricted reader: %v", err)
+	}
+
+	for _, ref := range []scriptorium.ArtifactRef{
+		{Type: scriptorium.ArtifactRefFile, URI: "nested/../input.md"},
+		{Type: scriptorium.ArtifactRefFile, URI: inputPath},
+	} {
+		artifact, err := reader.Read(context.Background(), ref)
+		if err != nil {
+			t.Fatalf("read contained path %q: %v", ref.URI, err)
+		}
+		if artifact.Name != "input.md" || artifact.URI != inputPath || artifact.Size != int64(len("allowed")) || string(artifact.Body) != "allowed" {
+			t.Fatalf("unexpected artifact metadata: %#v", artifact)
+		}
+		if artifact.ContentType != mime.TypeByExtension(".md") {
+			t.Fatalf("unexpected artifact content type: %q", artifact.ContentType)
+		}
+		if artifact.Hash != artifactHash([]byte("allowed")) {
+			t.Fatalf("unexpected artifact hash: %q", artifact.Hash)
+		}
+	}
+
+	artifact, err := reader.Read(context.Background(), scriptorium.File("input.unknown"))
+	if err != nil {
+		t.Fatalf("read unknown-extension path: %v", err)
+	}
+	if artifact.ContentType != fallbackArtifactContentType {
+		t.Fatalf("unexpected fallback content type: %q", artifact.ContentType)
+	}
+
+	for _, ref := range []scriptorium.ArtifactRef{
+		{Type: scriptorium.ArtifactRefFile, URI: filepath.Join("..", filepath.Base(outside), "secret.txt")},
+		{Type: scriptorium.ArtifactRefFile, URI: filepath.Join(outside, "secret.txt")},
+	} {
+		_, err := reader.Read(context.Background(), ref)
+		if !errors.Is(err, ErrFileOutsideRoot) {
+			t.Fatalf("expected ErrFileOutsideRoot for %q, got %v", ref.URI, err)
+		}
+	}
+}
+
+func TestRestrictedArtifactReaderFollowsSymlinkAfterLexicalCheck(t *testing.T) {
+	root := t.TempDir()
+	outside := t.TempDir()
+	target := filepath.Join(outside, "linked.txt")
+	if err := os.WriteFile(target, []byte("linked outside root"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.Symlink(target, filepath.Join(root, "linked.txt")); err != nil {
+		t.Skipf("symlink creation unavailable: %v", err)
+	}
+
+	reader, err := NewRestrictedArtifactReader(root, 0)
+	if err != nil {
+		t.Fatalf("construct restricted reader: %v", err)
+	}
+	artifact, err := reader.Read(context.Background(), scriptorium.File("linked.txt"))
+	if err != nil {
+		t.Fatalf("read symlink inside root: %v", err)
+	}
+	if string(artifact.Body) != "linked outside root" {
+		t.Fatalf("unexpected symlink artifact body: %q", artifact.Body)
+	}
+}
+
+func TestRestrictedArtifactReaderWithoutRootDeniesFiles(t *testing.T) {
+	reader, err := NewRestrictedArtifactReader("", 0)
+	if err != nil {
+		t.Fatalf("construct rootless reader: %v", err)
+	}
+
+	artifact, err := reader.Read(context.Background(), scriptorium.Inline("inline"))
+	if err != nil {
+		t.Fatalf("read inline artifact: %v", err)
+	}
+	if artifact.ContentType != fallbackArtifactContentType || string(artifact.Body) != "inline" || artifact.Hash != artifactHash([]byte("inline")) {
+		t.Fatalf("unexpected inline artifact: %#v", artifact)
+	}
+
+	_, err = reader.Read(context.Background(), scriptorium.File("input.txt"))
+	if !errors.Is(err, ErrFileNotAllowed) {
+		t.Fatalf("expected ErrFileNotAllowed, got %v", err)
+	}
+}
+
+func TestRestrictedArtifactReaderEnforcesLimits(t *testing.T) {
+	root := t.TempDir()
+	if err := os.WriteFile(filepath.Join(root, "exact.txt"), []byte("12345"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if err := os.WriteFile(filepath.Join(root, "large.txt"), []byte("123456"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	reader, err := NewRestrictedArtifactReader(root, 5)
+	if err != nil {
+		t.Fatalf("construct limited reader: %v", err)
+	}
+	artifact, err := reader.Read(context.Background(), scriptorium.File("exact.txt"))
+	if err != nil || string(artifact.Body) != "12345" {
+		t.Fatalf("expected exact-limit artifact, got %#v and %v", artifact, err)
+	}
+	_, err = reader.Read(context.Background(), scriptorium.File("large.txt"))
+	if !errors.Is(err, ErrFileTooLarge) {
+		t.Fatalf("expected ErrFileTooLarge, got %v", err)
+	}
+
+	unlimited, err := NewRestrictedArtifactReader(root, 0)
+	if err != nil {
+		t.Fatalf("construct unlimited reader: %v", err)
+	}
+	artifact, err = unlimited.Read(context.Background(), scriptorium.File("large.txt"))
+	if err != nil || string(artifact.Body) != "123456" {
+		t.Fatalf("expected unlimited artifact, got %#v and %v", artifact, err)
+	}
+
+	if _, err := NewRestrictedArtifactReader(root, -1); err == nil {
+		t.Fatal("expected negative limit to fail")
+	}
+}
+
+func TestRestrictedArtifactReaderRejectsCanceledAndMalformedReferences(t *testing.T) {
+	reader, err := NewRestrictedArtifactReader(t.TempDir(), 0)
+	if err != nil {
+		t.Fatalf("construct reader: %v", err)
+	}
+
+	canceledCtx, cancel := context.WithCancel(context.Background())
+	cancel()
+	for _, ref := range []scriptorium.ArtifactRef{
+		scriptorium.Inline("input"),
+		scriptorium.File("input.txt"),
+	} {
+		_, err := reader.Read(canceledCtx, ref)
+		if !errors.Is(err, context.Canceled) {
+			t.Fatalf("expected cancellation for %#v, got %v", ref, err)
+		}
+	}
+
+	for _, ref := range []scriptorium.ArtifactRef{
+		{Type: scriptorium.ArtifactRefType("unsupported")},
+		{Type: scriptorium.ArtifactRefInline},
+		{Type: scriptorium.ArtifactRefFile},
+	} {
+		if _, err := reader.Read(context.Background(), ref); err == nil {
+			t.Fatalf("expected malformed reference %#v to fail", ref)
+		}
+	}
+}

internal/adapter/http/handler.go

@@ -8,16 +8,12 @@ import (
 	"net/http"
 	"strings"
 
-	"gitea.maximumdirect.net/eric/scriptorium/internal/artifact"
+	"gitea.maximumdirect.net/eric/scriptorium"
 	"gitea.maximumdirect.net/eric/scriptorium/internal/defaults"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/profile"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/promptdef"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/usecase"
 )
 
 type Runner interface {
-	Run(ctx context.Context, req domain.RunRequest) (*domain.RunResult, error)
+	Run(ctx context.Context, req scriptorium.RunRequest) (*scriptorium.RunResult, error)
 }
 
 type Handler struct {
@@ -85,21 +81,21 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	mappedInputs := make(map[string]domain.ArtifactRef, len(req.Inputs))
+	mappedInputs := make(map[string]scriptorium.ArtifactRef, len(req.Inputs))
 	for name, in := range req.Inputs {
-		mappedInputs[name] = domain.ArtifactRef{
-			Type: domain.ArtifactRefType(in.Type),
+		mappedInputs[name] = scriptorium.ArtifactRef{
+			Type: scriptorium.ArtifactRefType(in.Type),
 			URI:  in.URI,
 			Body: in.Body,
 		}
 	}
 
-	var model *domain.ExecutionTargetOverride
+	var model *scriptorium.ExecutionTargetOverride
 	if req.Model != nil {
 		model = executionTargetOverrideFromModelOverrideDTO(req.Model)
 	}
 
-	res, err := h.runner.Run(r.Context(), domain.RunRequest{
+	res, err := h.runner.Run(r.Context(), scriptorium.RunRequest{
 		PromptID:      req.PromptID,
 		PromptVersion: req.PromptVersion,
 		ProfileID:     req.ProfileID,
@@ -156,11 +152,11 @@ func (h *Handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	writeLimitedJSON(w, http.StatusOK, resp, h.options.MaxResponseBytes)
 }
 
-func executionTargetOverrideFromModelOverrideDTO(dto *modelOverrideRequestDTO) *domain.ExecutionTargetOverride {
+func executionTargetOverrideFromModelOverrideDTO(dto *modelOverrideRequestDTO) *scriptorium.ExecutionTargetOverride {
 	if dto == nil {
 		return nil
 	}
-	return &domain.ExecutionTargetOverride{
+	return &scriptorium.ExecutionTargetOverride{
 		Endpoint:        dto.Endpoint,
 		Model:           dto.Model,
 		Temperature:     dto.Temperature,
@@ -174,7 +170,7 @@ func executionTargetOverrideFromModelOverrideDTO(dto *modelOverrideRequestDTO) *
 	}
 }
 
-func modelParamsDTOFromExecutionTarget(target domain.ExecutionTarget) modelParamsDTO {
+func modelParamsDTOFromExecutionTarget(target scriptorium.ExecutionTarget) modelParamsDTO {
 	return modelParamsDTO{
 		Endpoint:        target.Endpoint,
 		Model:           target.Model,
@@ -189,7 +185,7 @@ func modelParamsDTOFromExecutionTarget(target domain.ExecutionTarget) modelParam
 	}
 }
 
-func mapValidation(v domain.ValidationResult) validationDTO {
+func mapValidation(v scriptorium.ValidationResult) validationDTO {
 	return validationDTO{
 		Status:         string(v.Status),
 		Mode:           string(v.Mode),
@@ -202,35 +198,31 @@ func mapValidation(v domain.ValidationResult) validationDTO {
 
 func mapRunError(err error) (int, string, string) {
 	switch {
-	case errors.Is(err, promptdef.ErrPromptDefinitionNotFound):
+	case errors.Is(err, scriptorium.ErrPromptNotFound):
 		return http.StatusNotFound, "prompt_not_found", "prompt definition not found"
-	case errors.Is(err, profile.ErrProfileNotFound):
+	case errors.Is(err, scriptorium.ErrProfileNotFound):
 		return http.StatusNotFound, "profile_not_found", "execution profile not found"
-	case errors.Is(err, promptdef.ErrInvalidYAML), errors.Is(err, promptdef.ErrInvalidPromptDefinition):
-		return http.StatusBadRequest, "prompt_load_failed", "failed to load prompt definition"
-	case errors.Is(err, profile.ErrInvalidYAML), errors.Is(err, profile.ErrInvalidProfile), errors.Is(err, profile.ErrRawAPIKeyNotAllowed):
-		return http.StatusBadRequest, "profile_load_failed", "failed to load execution profile"
-	case errors.Is(err, usecase.ErrProfileRequired):
+	case errors.Is(err, scriptorium.ErrProfileRequired):
 		return http.StatusBadRequest, "profile_required", "profile_id is required when prompt default_profile is not set"
-	case errors.Is(err, usecase.ErrAPIKeyEnvMissing):
+	case errors.Is(err, scriptorium.ErrAPIKeyEnvMissing):
 		return http.StatusBadRequest, "api_key_env_missing", "api_key_env is set but the environment variable is missing"
-	case errors.Is(err, usecase.ErrInvalidRequest):
-		return http.StatusBadRequest, "invalid_request", "invalid run request"
-	case errors.Is(err, usecase.ErrPromptLoad):
+	case errors.Is(err, scriptorium.ErrPromptLoad):
 		return http.StatusBadRequest, "prompt_load_failed", "failed to load prompt definition"
-	case errors.Is(err, usecase.ErrProfileLoad):
+	case errors.Is(err, scriptorium.ErrProfileLoad):
 		return http.StatusBadRequest, "profile_load_failed", "failed to load execution profile"
-	case errors.Is(err, artifact.ErrFileNotAllowed), errors.Is(err, artifact.ErrFileOutsideRoot):
+	case errors.Is(err, scriptorium.ErrInvalidRequest):
+		return http.StatusBadRequest, "invalid_request", "invalid run request"
+	case errors.Is(err, ErrFileNotAllowed), errors.Is(err, ErrFileOutsideRoot):
 		return http.StatusBadRequest, "artifact_not_allowed", "file input artifact is not allowed"
-	case errors.Is(err, artifact.ErrFileTooLarge):
+	case errors.Is(err, ErrFileTooLarge):
 		return http.StatusRequestEntityTooLarge, "artifact_too_large", "file input artifact is too large"
-	case errors.Is(err, usecase.ErrArtifactLoad):
+	case errors.Is(err, scriptorium.ErrArtifactLoad):
 		return http.StatusBadRequest, "artifact_read_failed", "failed to read input artifact"
-	case errors.Is(err, usecase.ErrPromptRender):
+	case errors.Is(err, scriptorium.ErrPromptRender):
 		return http.StatusBadRequest, "prompt_render_failed", "failed to render prompt"
-	case errors.Is(err, usecase.ErrLLMGenerate):
+	case errors.Is(err, scriptorium.ErrLLMGenerate):
 		return http.StatusBadGateway, "llm_failed", "model generation request failed"
-	case errors.Is(err, usecase.ErrValidation):
+	case errors.Is(err, scriptorium.ErrValidation):
 		return http.StatusInternalServerError, "validation_runtime_failed", "validation runtime failed"
 	default:
 		return http.StatusInternalServerError, "internal_error", "internal server error"

internal/adapter/http/handler_test.go

@@ -14,21 +14,16 @@ import (
 	"testing"
 	"time"
 
-	"gitea.maximumdirect.net/eric/scriptorium/internal/artifact"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/llm"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/profile"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/promptdef"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/usecase"
+	"gitea.maximumdirect.net/eric/scriptorium"
 )
 
 type fakeRunner struct {
-	result *domain.RunResult
+	result *scriptorium.RunResult
 	err    error
-	last   domain.RunRequest
+	last   scriptorium.RunRequest
 }
 
-func (f *fakeRunner) Run(ctx context.Context, req domain.RunRequest) (*domain.RunResult, error) {
+func (f *fakeRunner) Run(ctx context.Context, req scriptorium.RunRequest) (*scriptorium.RunResult, error) {
 	f.last = req
 	if f.err != nil {
 		return nil, f.err
@@ -42,7 +37,7 @@ func TestMaintainedHTTPRunExampleMatchesRequestContract(t *testing.T) {
 		t.Fatalf("read maintained HTTP request example: %v", err)
 	}
 
-	runner := &fakeRunner{result: &domain.RunResult{}}
+	runner := &fakeRunner{result: &scriptorium.RunResult{}}
 	h := NewHandler(runner)
 	req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewReader(body))
 	w := httptest.NewRecorder()
@@ -68,38 +63,10 @@ func TestMaintainedHTTPRunExampleMatchesRequestContract(t *testing.T) {
 	assertHTTPErrorCode(t, invalidW, http.StatusBadRequest, "invalid_json")
 }
 
-type handlerPromptRepo struct {
-	def *domain.PromptDefinition
-}
-
-func (r handlerPromptRepo) GetPromptDefinition(ctx context.Context, id string, version string) (*domain.PromptDefinition, error) {
-	return r.def, nil
-}
-
-type handlerProfileRepo struct {
-	profile *domain.ExecutionProfile
-}
-
-func (r handlerProfileRepo) GetProfile(ctx context.Context, id string) (*domain.ExecutionProfile, error) {
-	return r.profile, nil
-}
-
-type handlerArtifactReader struct{}
-
-func (handlerArtifactReader) Read(ctx context.Context, ref domain.ArtifactRef) (*domain.Artifact, error) {
-	return &domain.Artifact{Name: "input", Body: []byte("input"), Hash: "hash"}, nil
-}
-
-type handlerRenderer struct{}
-
-func (handlerRenderer) Render(ctx context.Context, definition *domain.PromptDefinition, inputs map[string]*domain.Artifact, vars map[string]string) (*domain.RenderedPrompt, error) {
-	return &domain.RenderedPrompt{Messages: []domain.RenderedMessage{{Role: "user", Content: "hi"}}}, nil
-}
-
 type handlerLLMClient struct{}
 
-func (handlerLLMClient) Generate(ctx context.Context, req domain.GenerateRequest) (*domain.GenerateResponse, error) {
-	return &domain.GenerateResponse{Content: "ok"}, nil
+func (handlerLLMClient) Generate(ctx context.Context, req scriptorium.GenerateRequest) (*scriptorium.GenerateResponse, error) {
+	return &scriptorium.GenerateResponse{Content: "ok"}, nil
 }
 
 func TestHandlerPostRunsSuccessWithExplicitProfileID(t *testing.T) {
@@ -108,16 +75,16 @@ func TestHandlerPostRunsSuccessWithExplicitProfileID(t *testing.T) {
 	const envName = "SCRIPTORIUM_API_KEY"
 	const secret = "never-include-me"
 
-	r := &fakeRunner{result: &domain.RunResult{
+	r := &fakeRunner{result: &scriptorium.RunResult{
 		RunID: "11111111-1111-4111-8111-111111111111",
-		Artifact: domain.Artifact{
+		Artifact: scriptorium.Artifact{
 			Name:        "output",
 			ContentType: "text/plain",
 			Body:        []byte("hello"),
 			Size:        5,
 			Hash:        "abc",
 		},
-		Validation:         domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
+		Validation:         scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
 		PromptID:           "prompt-1",
 		PromptVersion:      "1.0.0",
 		PromptHash:         "phash",
@@ -125,7 +92,7 @@ func TestHandlerPostRunsSuccessWithExplicitProfileID(t *testing.T) {
 		SelectedProfileID:  "exec-default",
 		ModelName:          "m1",
 		Endpoint:           "http://llm/v1",
-		EffectiveModelParams: domain.ExecutionTarget{
+		EffectiveModelParams: scriptorium.ExecutionTarget{
 			Endpoint:       "http://llm/v1",
 			Model:          "m1",
 			Temperature:    0.2,
@@ -136,7 +103,7 @@ func TestHandlerPostRunsSuccessWithExplicitProfileID(t *testing.T) {
 			APIKeyEnv:      envName,
 		},
 		InputHashes: map[string]string{"transcript": "h1"},
-		Usage: domain.TokenUsage{
+		Usage: scriptorium.TokenUsage{
 			PromptTokens:     1,
 			CompletionTokens: 2,
 			TotalTokens:      3,
@@ -325,13 +292,13 @@ func TestHandlerFileRefsOutsideArtifactRootAreRejected(t *testing.T) {
 }
 
 func TestHandlerPostRunsSuccessUsingPromptDefaultProfile(t *testing.T) {
-	r := &fakeRunner{result: &domain.RunResult{
-		Artifact:             domain.Artifact{Body: []byte("ok")},
+	r := &fakeRunner{result: &scriptorium.RunResult{
+		Artifact:             scriptorium.Artifact{Body: []byte("ok")},
 		PromptID:             "prompt-1",
 		PromptVersion:        "1.0.0",
 		SelectedProfileID:    "prompt-default",
-		Validation:           domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
-		EffectiveModelParams: domain.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
+		Validation:           scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
+		EffectiveModelParams: scriptorium.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
 	}}
 	h := NewHandler(r)
 
@@ -360,10 +327,10 @@ func TestHandlerPostRunsSuccessUsingPromptDefaultProfile(t *testing.T) {
 }
 
 func TestHandlerModelOverrideMapsAllSupportedExecutionFields(t *testing.T) {
-	r := &fakeRunner{result: &domain.RunResult{
-		Artifact:             domain.Artifact{Body: []byte("ok")},
-		Validation:           domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
-		EffectiveModelParams: domain.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
+	r := &fakeRunner{result: &scriptorium.RunResult{
+		Artifact:             scriptorium.Artifact{Body: []byte("ok")},
+		Validation:           scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
+		EffectiveModelParams: scriptorium.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
 	}}
 	h := NewHandler(r)
 
@@ -420,10 +387,10 @@ func TestHandlerModelOverrideMapsAllSupportedExecutionFields(t *testing.T) {
 }
 
 func TestHandlerModelOverrideAcceptsJSONCompatibleExtraParams(t *testing.T) {
-	r := &fakeRunner{result: &domain.RunResult{
-		Artifact:             domain.Artifact{Body: []byte("ok")},
-		Validation:           domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
-		EffectiveModelParams: domain.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
+	r := &fakeRunner{result: &scriptorium.RunResult{
+		Artifact:             scriptorium.Artifact{Body: []byte("ok")},
+		Validation:           scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
+		EffectiveModelParams: scriptorium.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
 	}}
 	h := NewHandler(r)
 
@@ -464,10 +431,10 @@ func TestHandlerModelOverrideAcceptsJSONCompatibleExtraParams(t *testing.T) {
 }
 
 func TestHandlerModelOverrideExplicitZeroTemperatureMapsAsPresent(t *testing.T) {
-	r := &fakeRunner{result: &domain.RunResult{
-		Artifact:             domain.Artifact{Body: []byte("ok")},
-		Validation:           domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
-		EffectiveModelParams: domain.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1", Temperature: 0},
+	r := &fakeRunner{result: &scriptorium.RunResult{
+		Artifact:             scriptorium.Artifact{Body: []byte("ok")},
+		Validation:           scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
+		EffectiveModelParams: scriptorium.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1", Temperature: 0},
 	}}
 	h := NewHandler(r)
 
@@ -491,10 +458,10 @@ func TestHandlerModelOverrideExplicitZeroTemperatureMapsAsPresent(t *testing.T)
 }
 
 func TestHandlerModelOverrideOmittedTemperatureMapsAsAbsent(t *testing.T) {
-	r := &fakeRunner{result: &domain.RunResult{
-		Artifact:             domain.Artifact{Body: []byte("ok")},
-		Validation:           domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
-		EffectiveModelParams: domain.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1", Temperature: 0.7},
+	r := &fakeRunner{result: &scriptorium.RunResult{
+		Artifact:             scriptorium.Artifact{Body: []byte("ok")},
+		Validation:           scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
+		EffectiveModelParams: scriptorium.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1", Temperature: 0.7},
 	}}
 	h := NewHandler(r)
 
@@ -528,16 +495,16 @@ func TestHandlerModelOverrideOmittedTemperatureMapsAsAbsent(t *testing.T) {
 }
 
 func TestHandlerResponseMetadataModelParamsIncludesAllSupportedFields(t *testing.T) {
-	r := &fakeRunner{result: &domain.RunResult{
-		Artifact: domain.Artifact{
+	r := &fakeRunner{result: &scriptorium.RunResult{
+		Artifact: scriptorium.Artifact{
 			Name:        "output",
 			ContentType: "text/plain",
 			Body:        []byte("ok"),
 			Size:        2,
 			Hash:        "abc",
 		},
-		Validation: domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
-		EffectiveModelParams: domain.ExecutionTarget{
+		Validation: scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
+		EffectiveModelParams: scriptorium.ExecutionTarget{
 			Endpoint:        "http://llm/v1",
 			Model:           "gpt-test",
 			Temperature:     0.4,
@@ -657,10 +624,10 @@ func TestHandlerMalformedJSONBelowLimitStillBadRequest(t *testing.T) {
 }
 
 func TestHandlerResponseTooLarge(t *testing.T) {
-	h := NewHandlerWithOptions(&fakeRunner{result: &domain.RunResult{
-		Artifact:             domain.Artifact{Body: []byte(strings.Repeat("x", 128))},
-		Validation:           domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
-		EffectiveModelParams: domain.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
+	h := NewHandlerWithOptions(&fakeRunner{result: &scriptorium.RunResult{
+		Artifact:             scriptorium.Artifact{Body: []byte(strings.Repeat("x", 128))},
+		Validation:           scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
+		EffectiveModelParams: scriptorium.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
 	}}, HandlerOptions{MaxRequestBytes: 1024, MaxResponseBytes: 64})
 	req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewBufferString(`{"prompt_id":"p","inputs":{"x":{"type":"file","uri":"a"}}}`))
 	w := httptest.NewRecorder()
@@ -671,11 +638,11 @@ func TestHandlerResponseTooLarge(t *testing.T) {
 }
 
 func TestHandlerRawOutputDoesNotBypassResponseLimit(t *testing.T) {
-	h := NewHandlerWithOptions(&fakeRunner{result: &domain.RunResult{
-		Artifact:             domain.Artifact{Body: []byte("ok")},
+	h := NewHandlerWithOptions(&fakeRunner{result: &scriptorium.RunResult{
+		Artifact:             scriptorium.Artifact{Body: []byte("ok")},
 		RawOutput:            strings.Repeat("raw", 80),
-		Validation:           domain.ValidationResult{Status: domain.ValidationPassed, Mode: domain.ValidationBasic, IsValid: true},
-		EffectiveModelParams: domain.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
+		Validation:           scriptorium.ValidationResult{Status: scriptorium.ValidationPassed, Mode: scriptorium.ValidationBasic, IsValid: true},
+		EffectiveModelParams: scriptorium.ExecutionTarget{Endpoint: "http://llm/v1", Model: "m1"},
 	}}, HandlerOptions{MaxRequestBytes: 1024, MaxResponseBytes: 128})
 	req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewBufferString(`{
 		"prompt_id":"p",
@@ -709,35 +676,12 @@ func TestHandlerMissingPromptID(t *testing.T) {
 	}
 }
 
-func TestHandlerReservedExtraParamsThroughRunnerMapsToInvalidRequest(t *testing.T) {
-	llmClient, err := llm.NewOpenAICompatibleClient(llm.OpenAICompatibleConfig{})
-	if err != nil {
-		t.Fatal(err)
-	}
-	runner := usecase.NewRunner(
-		handlerPromptRepo{def: &domain.PromptDefinition{
-			ID:             "p",
-			Version:        "1",
-			DefaultProfile: "exec",
-			Templates:      []domain.PromptMessageTemplate{{Role: "user", Content: "hi"}},
-			OutputFormat:   domain.FormatText,
-			Validation:     domain.OutputContract{Format: domain.FormatText, ValidationMode: domain.ValidationNone},
-		}},
-		handlerProfileRepo{profile: &domain.ExecutionProfile{
-			ID:       "exec",
-			Endpoint: "http://example.invalid/v1",
-			Model:    "model",
-		}},
-		handlerArtifactReader{},
-		handlerRenderer{},
-		llmClient,
-		nil,
-	)
-	h := NewHandler(runner)
+func TestHandlerReservedExtraParamsThroughEngineMapsToInvalidRequest(t *testing.T) {
+	h := NewHandler(newHandlerEngineWithDefaultClient(t))
 
 	req := httptest.NewRequest(http.MethodPost, "/v1/runs", bytes.NewBufferString(`{
 		"prompt_id":"p",
-		"inputs":{"x":{"type":"file","uri":"a"}},
+		"inputs":{"x":{"type":"inline","body":"input"}},
 		"model":{"extra_params":{"model":"collision"}}
 	}`))
 	w := httptest.NewRecorder()
@@ -757,7 +701,7 @@ func TestHandlerReservedExtraParamsThroughRunnerMapsToInvalidRequest(t *testing.
 	}
 }
 
-func TestHandlerUsecaseErrorMapping(t *testing.T) {
+func TestHandlerPublicErrorMapping(t *testing.T) {
 	tests := []struct {
 		name       string
 		err        error
@@ -766,18 +710,20 @@ func TestHandlerUsecaseErrorMapping(t *testing.T) {
 		message    string
 		avoidCause string
 	}{
-		{name: "prompt not found", err: wrap(usecase.ErrPromptLoad, promptdef.ErrPromptDefinitionNotFound), status: http.StatusNotFound, code: "prompt_not_found", message: "prompt definition not found"},
-		{name: "prompt load invalid", err: wrap(usecase.ErrPromptLoad, promptdef.ErrInvalidPromptDefinition), status: http.StatusBadRequest, code: "prompt_load_failed", message: "failed to load prompt definition"},
-		{name: "prompt load generic", err: wrap(usecase.ErrPromptLoad, fmt.Errorf("read failed")), status: http.StatusBadRequest, code: "prompt_load_failed", message: "failed to load prompt definition", avoidCause: "read failed"},
-		{name: "missing profile/default", err: wrap(usecase.ErrInvalidRequest, usecase.ErrProfileRequired), status: http.StatusBadRequest, code: "profile_required", message: "profile_id is required when prompt default_profile is not set"},
-		{name: "profile not found", err: wrap(usecase.ErrProfileLoad, profile.ErrProfileNotFound), status: http.StatusNotFound, code: "profile_not_found", message: "execution profile not found"},
-		{name: "profile invalid", err: wrap(usecase.ErrProfileLoad, profile.ErrInvalidProfile), status: http.StatusBadRequest, code: "profile_load_failed", message: "failed to load execution profile"},
-		{name: "profile load generic", err: wrap(usecase.ErrProfileLoad, fmt.Errorf("read failed")), status: http.StatusBadRequest, code: "profile_load_failed", message: "failed to load execution profile", avoidCause: "read failed"},
-		{name: "api key env missing", err: wrap(usecase.ErrInvalidRequest, usecase.ErrAPIKeyEnvMissing), status: http.StatusBadRequest, code: "api_key_env_missing", message: "api_key_env is set but the environment variable is missing"},
-		{name: "artifact", err: wrap(usecase.ErrArtifactLoad, fmt.Errorf("read failed")), status: http.StatusBadRequest, code: "artifact_read_failed", message: "failed to read input artifact", avoidCause: "read failed"},
-		{name: "prompt render", err: wrap(usecase.ErrPromptRender, fmt.Errorf("render failed")), status: http.StatusBadRequest, code: "prompt_render_failed", message: "failed to render prompt", avoidCause: "render failed"},
-		{name: "llm", err: wrap(usecase.ErrLLMGenerate, fmt.Errorf("llm failed")), status: http.StatusBadGateway, code: "llm_failed", message: "model generation request failed", avoidCause: "llm failed"},
-		{name: "validation runtime", err: wrap(usecase.ErrValidation, fmt.Errorf("validator broke")), status: http.StatusInternalServerError, code: "validation_runtime_failed", message: "validation runtime failed", avoidCause: "validator broke"},
+		{name: "prompt not found", err: scriptorium.ErrPromptNotFound, status: http.StatusNotFound, code: "prompt_not_found", message: "prompt definition not found"},
+		{name: "prompt load", err: wrap(scriptorium.ErrPromptLoad, fmt.Errorf("read failed")), status: http.StatusBadRequest, code: "prompt_load_failed", message: "failed to load prompt definition", avoidCause: "read failed"},
+		{name: "missing profile/default", err: wrap(scriptorium.ErrProfileRequired, scriptorium.ErrInvalidRequest), status: http.StatusBadRequest, code: "profile_required", message: "profile_id is required when prompt default_profile is not set"},
+		{name: "profile not found", err: scriptorium.ErrProfileNotFound, status: http.StatusNotFound, code: "profile_not_found", message: "execution profile not found"},
+		{name: "profile load", err: wrap(scriptorium.ErrProfileLoad, fmt.Errorf("read failed")), status: http.StatusBadRequest, code: "profile_load_failed", message: "failed to load execution profile", avoidCause: "read failed"},
+		{name: "api key env missing", err: wrap(scriptorium.ErrAPIKeyEnvMissing, scriptorium.ErrInvalidRequest), status: http.StatusBadRequest, code: "api_key_env_missing", message: "api_key_env is set but the environment variable is missing"},
+		{name: "invalid request", err: scriptorium.ErrInvalidRequest, status: http.StatusBadRequest, code: "invalid_request", message: "invalid run request"},
+		{name: "file denied", err: ErrFileNotAllowed, status: http.StatusBadRequest, code: "artifact_not_allowed", message: "file input artifact is not allowed"},
+		{name: "file outside root", err: ErrFileOutsideRoot, status: http.StatusBadRequest, code: "artifact_not_allowed", message: "file input artifact is not allowed"},
+		{name: "file too large", err: ErrFileTooLarge, status: http.StatusRequestEntityTooLarge, code: "artifact_too_large", message: "file input artifact is too large"},
+		{name: "artifact", err: wrap(scriptorium.ErrArtifactLoad, fmt.Errorf("read failed")), status: http.StatusBadRequest, code: "artifact_read_failed", message: "failed to read input artifact", avoidCause: "read failed"},
+		{name: "prompt render", err: wrap(scriptorium.ErrPromptRender, fmt.Errorf("render failed")), status: http.StatusBadRequest, code: "prompt_render_failed", message: "failed to render prompt", avoidCause: "render failed"},
+		{name: "llm", err: wrap(scriptorium.ErrLLMGenerate, fmt.Errorf("llm failed")), status: http.StatusBadGateway, code: "llm_failed", message: "model generation request failed", avoidCause: "llm failed"},
+		{name: "validation runtime", err: wrap(scriptorium.ErrValidation, fmt.Errorf("validator broke")), status: http.StatusInternalServerError, code: "validation_runtime_failed", message: "validation runtime failed", avoidCause: "validator broke"},
 	}
 
 	for _, tc := range tests {
@@ -830,12 +776,12 @@ func TestHandlerRawAPIKeyRejectedByStrictJSON(t *testing.T) {
 }
 
 func TestHandlerValidationFailureStillSuccessAndRawOutputOptIn(t *testing.T) {
-	h := NewHandler(&fakeRunner{result: &domain.RunResult{
-		Artifact:  domain.Artifact{Body: []byte("bad json")},
+	h := NewHandler(&fakeRunner{result: &scriptorium.RunResult{
+		Artifact:  scriptorium.Artifact{Body: []byte("bad json")},
 		RawOutput: "bad json",
-		Validation: domain.ValidationResult{
-			Status: domain.ValidationFailed,
-			Mode:   domain.ValidationJSON,
+		Validation: scriptorium.ValidationResult{
+			Status: scriptorium.ValidationFailed,
+			Mode:   scriptorium.ValidationJSON,
 			Errors: []string{"invalid JSON"},
 		},
 	}})
@@ -889,30 +835,58 @@ func newArtifactRootHandler(t *testing.T, root string) *Handler {
 func newArtifactRootHandlerWithLimit(t *testing.T, root string, maxArtifactBytes int64) *Handler {
 	t.Helper()
 
-	reader, err := artifact.NewRestrictedCompositeReaderWithLimit(root, maxArtifactBytes)
+	reader, err := NewRestrictedArtifactReader(root, maxArtifactBytes)
 	if err != nil {
 		t.Fatalf("expected restricted artifact reader: %v", err)
 	}
-	runner := usecase.NewRunner(
-		handlerPromptRepo{def: &domain.PromptDefinition{
-			ID:             "p",
-			Version:        "1",
-			DefaultProfile: "exec",
-			Templates:      []domain.PromptMessageTemplate{{Role: "user", Content: "hi"}},
-			OutputFormat:   domain.FormatText,
-			Validation:     domain.OutputContract{Format: domain.FormatText, ValidationMode: domain.ValidationNone},
-		}},
-		handlerProfileRepo{profile: &domain.ExecutionProfile{
-			ID:       "exec",
-			Endpoint: "http://example.invalid/v1",
-			Model:    "model",
-		}},
-		reader,
-		handlerRenderer{},
-		handlerLLMClient{},
-		nil,
-	)
-	return NewHandler(runner)
+	return NewHandler(newHandlerEngine(t, scriptorium.WithArtifactReader(reader)))
+}
+
+func newHandlerEngine(t *testing.T, options ...scriptorium.Option) *scriptorium.Engine {
+	t.Helper()
+
+	return newHandlerEngineWithOptions(t, append(options, scriptorium.WithLLMClient(handlerLLMClient{}))...)
+}
+
+func newHandlerEngineWithDefaultClient(t *testing.T, options ...scriptorium.Option) *scriptorium.Engine {
+	t.Helper()
+
+	return newHandlerEngineWithOptions(t, options...)
+}
+
+func newHandlerEngineWithOptions(t *testing.T, options ...scriptorium.Option) *scriptorium.Engine {
+	t.Helper()
+
+	promptDir := t.TempDir()
+	profileDir := t.TempDir()
+	if err := os.WriteFile(filepath.Join(promptDir, "prompt.yaml"), []byte(`id: p
+version: "1"
+default_profile: exec
+messages:
+  - role: user
+    content: "hi"
+output:
+  format: text
+  validation_mode: none
+  repair_attempts: 0
+`), 0o644); err != nil {
+		t.Fatalf("write prompt fixture: %v", err)
+	}
+	if err := os.WriteFile(filepath.Join(profileDir, "profile.yaml"), []byte(`id: exec
+endpoint: http://example.invalid/v1
+model: model
+`), 0o644); err != nil {
+		t.Fatalf("write profile fixture: %v", err)
+	}
+
+	engine, err := scriptorium.NewEngine(scriptorium.Config{
+		PromptDir:  promptDir,
+		ProfileDir: profileDir,
+	}, options...)
+	if err != nil {
+		t.Fatalf("construct public engine: %v", err)
+	}
+	return engine
 }
 
 func assertHTTPErrorCode(t *testing.T, w *httptest.ResponseRecorder, status int, code string) {

internal/artifact/reader.go

@@ -5,22 +5,19 @@ import (
 	"crypto/sha256"
 	"errors"
 	"fmt"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/defaults"
-	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
 	"io"
 	"mime"
 	"os"
 	"path/filepath"
-	"strings"
+
+	"gitea.maximumdirect.net/eric/scriptorium/internal/defaults"
+	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
 )
 
 var (
 	ErrUnsupportedRefType = errors.New("unsupported artifact reference type")
 	ErrMissingInlineBody  = errors.New("missing body for inline artifact")
 	ErrMissingFilePath    = errors.New("missing file path for file artifact")
-	ErrFileNotAllowed     = errors.New("file artifact references are not allowed")
-	ErrFileOutsideRoot    = errors.New("file artifact path is outside artifact root")
-	ErrFileTooLarge       = errors.New("file artifact exceeds size limit")
 )
 
 // Reader resolves artifact references into actual artifacts.
@@ -41,21 +38,6 @@ func NewCompositeReader() Reader {
 	}
 }
 
-func NewRestrictedCompositeReader(root string) (Reader, error) {
-	return NewRestrictedCompositeReaderWithLimit(root, 0)
-}
-
-func NewRestrictedCompositeReaderWithLimit(root string, maxBytes int64) (Reader, error) {
-	fileReader, err := newRestrictedFileReader(root, maxBytes)
-	if err != nil {
-		return nil, err
-	}
-	return &CompositeReader{
-		inlineReader: &inlineReader{},
-		fileReader:   fileReader,
-	}, nil
-}
-
 func (c *CompositeReader) Read(ctx context.Context, ref domain.ArtifactRef) (*domain.Artifact, error) {
 	select {
 	case <-ctx.Done():
@@ -112,119 +94,17 @@ func (r *fileReader) Read(ctx context.Context, ref domain.ArtifactRef) (*domain.
 	return readFileArtifact(ref.URI)
 }
 
-type deniedFileReader struct{}
-
-func (r deniedFileReader) Read(ctx context.Context, ref domain.ArtifactRef) (*domain.Artifact, error) {
-	select {
-	case <-ctx.Done():
-		return nil, ctx.Err()
-	default:
-	}
-
-	if ref.URI == "" {
-		return nil, ErrMissingFilePath
-	}
-	return nil, ErrFileNotAllowed
-}
-
-type restrictedFileReader struct {
-	root     string
-	maxBytes int64
-}
-
-func newRestrictedFileReader(root string, maxBytes int64) (Reader, error) {
-	if maxBytes < 0 {
-		return nil, fmt.Errorf("artifact size limit must be greater than or equal to 0")
-	}
-	cleanRoot := strings.TrimSpace(root)
-	if cleanRoot == "" {
-		return deniedFileReader{}, nil
-	}
-	absRoot, err := filepath.Abs(filepath.Clean(cleanRoot))
-	if err != nil {
-		return nil, fmt.Errorf("resolve artifact root: %w", err)
-	}
-	return &restrictedFileReader{root: absRoot, maxBytes: maxBytes}, nil
-}
-
-func (r *restrictedFileReader) Read(ctx context.Context, ref domain.ArtifactRef) (*domain.Artifact, error) {
-	select {
-	case <-ctx.Done():
-		return nil, ctx.Err()
-	default:
-	}
-
-	if ref.URI == "" {
-		return nil, ErrMissingFilePath
-	}
-
-	path, err := r.resolveLexicalPath(ref.URI)
-	if err != nil {
-		return nil, err
-	}
-	return readFileArtifactWithLimit(path, r.maxBytes)
-}
-
-// resolveLexicalPath checks cleaned path containment without resolving symlinks.
-func (r *restrictedFileReader) resolveLexicalPath(rawPath string) (string, error) {
-	cleanPath := filepath.Clean(strings.TrimSpace(rawPath))
-	var candidate string
-	if filepath.IsAbs(cleanPath) {
-		candidate = cleanPath
-	} else {
-		candidate = filepath.Join(r.root, cleanPath)
-	}
-
-	absCandidate, err := filepath.Abs(candidate)
-	if err != nil {
-		return "", fmt.Errorf("resolve artifact path: %w", err)
-	}
-	absCandidate = filepath.Clean(absCandidate)
-
-	rel, err := filepath.Rel(r.root, absCandidate)
-	if err != nil {
-		return "", fmt.Errorf("compare artifact path to root: %w", err)
-	}
-	if rel == ".." || strings.HasPrefix(rel, ".."+string(filepath.Separator)) || filepath.IsAbs(rel) {
-		return "", ErrFileOutsideRoot
-	}
-	return absCandidate, nil
-}
-
 func readFileArtifact(path string) (*domain.Artifact, error) {
-	return readFileArtifactWithLimit(path, 0)
-}
-
-func readFileArtifactWithLimit(path string, maxBytes int64) (*domain.Artifact, error) {
-	if maxBytes < 0 {
-		return nil, fmt.Errorf("file size limit must be greater than or equal to 0")
-	}
-
 	file, err := os.Open(path)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read file %s: %w", path, err)
 	}
 	defer file.Close()
 
-	info, err := file.Stat()
-	if err != nil {
-		return nil, fmt.Errorf("failed to stat file %s: %w", path, err)
-	}
-	if maxBytes > 0 && info.Size() > maxBytes {
-		return nil, ErrFileTooLarge
-	}
-
-	var reader io.Reader = file
-	if maxBytes > 0 {
-		reader = io.LimitReader(file, maxBytes+1)
-	}
-	data, err := io.ReadAll(reader)
+	data, err := io.ReadAll(file)
 	if err != nil {
 		return nil, fmt.Errorf("failed to read file %s: %w", path, err)
 	}
-	if maxBytes > 0 && int64(len(data)) > maxBytes {
-		return nil, ErrFileTooLarge
-	}
 
 	contentType := mime.TypeByExtension(filepath.Ext(path))
 	if contentType == "" {

internal/artifact/reader_test.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"os"
-	"path/filepath"
 	"testing"
 
 	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
@@ -57,157 +56,6 @@ func TestCompositeReader_Read(t *testing.T) {
 	})
 }
 
-func TestRestrictedCompositeReader(t *testing.T) {
-	ctx := context.Background()
-	root := t.TempDir()
-	outside := t.TempDir()
-
-	if err := os.WriteFile(filepath.Join(root, "input.txt"), []byte("allowed"), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.Mkdir(filepath.Join(root, "nested"), 0o755); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(outside, "secret.txt"), []byte("denied"), 0o644); err != nil {
-		t.Fatal(err)
-	}
-
-	reader, err := NewRestrictedCompositeReader(root)
-	if err != nil {
-		t.Fatalf("expected restricted reader construction, got %v", err)
-	}
-
-	t.Run("accepts relative contained path", func(t *testing.T) {
-		art, err := reader.Read(ctx, domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: "nested/../input.txt"})
-		if err != nil {
-			t.Fatalf("expected contained relative path to succeed, got %v", err)
-		}
-		if string(art.Body) != "allowed" {
-			t.Fatalf("unexpected artifact body: %q", string(art.Body))
-		}
-	})
-
-	t.Run("accepts absolute contained path", func(t *testing.T) {
-		art, err := reader.Read(ctx, domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: filepath.Join(root, "input.txt")})
-		if err != nil {
-			t.Fatalf("expected contained absolute path to succeed, got %v", err)
-		}
-		if art.Name != "input.txt" {
-			t.Fatalf("unexpected artifact name: %q", art.Name)
-		}
-	})
-
-	t.Run("rejects relative traversal outside root", func(t *testing.T) {
-		_, err := reader.Read(ctx, domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: filepath.Join("..", filepath.Base(outside), "secret.txt")})
-		if !errors.Is(err, ErrFileOutsideRoot) {
-			t.Fatalf("expected ErrFileOutsideRoot, got %v", err)
-		}
-	})
-
-	t.Run("rejects absolute path outside root", func(t *testing.T) {
-		_, err := reader.Read(ctx, domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: filepath.Join(outside, "secret.txt")})
-		if !errors.Is(err, ErrFileOutsideRoot) {
-			t.Fatalf("expected ErrFileOutsideRoot, got %v", err)
-		}
-	})
-}
-
-func TestRestrictedCompositeReaderFollowsSymlinkInsideRoot(t *testing.T) {
-	ctx := context.Background()
-	root := t.TempDir()
-	outside := t.TempDir()
-
-	target := filepath.Join(outside, "linked.txt")
-	if err := os.WriteFile(target, []byte("linked outside root"), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	link := filepath.Join(root, "linked.txt")
-	if err := os.Symlink(target, link); err != nil {
-		t.Skipf("symlink creation unavailable: %v", err)
-	}
-
-	reader, err := NewRestrictedCompositeReader(root)
-	if err != nil {
-		t.Fatalf("expected restricted reader construction, got %v", err)
-	}
-
-	art, err := reader.Read(ctx, domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: "linked.txt"})
-	if err != nil {
-		t.Fatalf("expected symlink inside root to be followed, got %v", err)
-	}
-	if string(art.Body) != "linked outside root" {
-		t.Fatalf("unexpected artifact body: %q", string(art.Body))
-	}
-}
-
-func TestRestrictedCompositeReaderWithoutRootDeniesFileRefs(t *testing.T) {
-	reader, err := NewRestrictedCompositeReader("")
-	if err != nil {
-		t.Fatalf("expected restricted reader construction, got %v", err)
-	}
-
-	art, err := reader.Read(context.Background(), domain.ArtifactRef{Type: domain.ArtifactRefInline, Body: "inline"})
-	if err != nil {
-		t.Fatalf("expected inline ref to work without artifact root, got %v", err)
-	}
-	if string(art.Body) != "inline" {
-		t.Fatalf("unexpected inline body: %q", string(art.Body))
-	}
-
-	_, err = reader.Read(context.Background(), domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: "input.txt"})
-	if !errors.Is(err, ErrFileNotAllowed) {
-		t.Fatalf("expected ErrFileNotAllowed, got %v", err)
-	}
-}
-
-func TestRestrictedCompositeReaderFileSizeLimit(t *testing.T) {
-	ctx := context.Background()
-	root := t.TempDir()
-	if err := os.WriteFile(filepath.Join(root, "exact.txt"), []byte("12345"), 0o644); err != nil {
-		t.Fatal(err)
-	}
-	if err := os.WriteFile(filepath.Join(root, "large.txt"), []byte("123456"), 0o644); err != nil {
-		t.Fatal(err)
-	}
-
-	reader, err := NewRestrictedCompositeReaderWithLimit(root, 5)
-	if err != nil {
-		t.Fatalf("expected restricted reader construction, got %v", err)
-	}
-
-	art, err := reader.Read(ctx, domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: "exact.txt"})
-	if err != nil {
-		t.Fatalf("expected file at limit to succeed, got %v", err)
-	}
-	if string(art.Body) != "12345" {
-		t.Fatalf("unexpected artifact body: %q", string(art.Body))
-	}
-
-	_, err = reader.Read(ctx, domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: "large.txt"})
-	if !errors.Is(err, ErrFileTooLarge) {
-		t.Fatalf("expected ErrFileTooLarge, got %v", err)
-	}
-}
-
-func TestRestrictedCompositeReaderFileSizeLimitZeroDisablesLimit(t *testing.T) {
-	root := t.TempDir()
-	if err := os.WriteFile(filepath.Join(root, "large.txt"), []byte("123456"), 0o644); err != nil {
-		t.Fatal(err)
-	}
-
-	reader, err := NewRestrictedCompositeReaderWithLimit(root, 0)
-	if err != nil {
-		t.Fatalf("expected restricted reader construction, got %v", err)
-	}
-	art, err := reader.Read(context.Background(), domain.ArtifactRef{Type: domain.ArtifactRefFile, URI: "large.txt"})
-	if err != nil {
-		t.Fatalf("expected unlimited reader to succeed, got %v", err)
-	}
-	if string(art.Body) != "123456" {
-		t.Fatalf("unexpected artifact body: %q", string(art.Body))
-	}
-}
-
 func TestFileReader_Read(t *testing.T) {
 	content := []byte("test file content")
 	tmpFile, err := os.CreateTemp("", "artifact_test_*.txt")

internal/format/prepared_run.go

@@ -1,4 +1,4 @@
-// Package format formats already-prepared domain data for adapters.
+// Package format formats already-prepared public data for adapters.
 package format
 
 import (
@@ -9,7 +9,7 @@ import (
 	"sort"
 	"strings"
 
-	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
+	"gitea.maximumdirect.net/eric/scriptorium"
 )
 
 var ErrUnknownPreparedRunFormat = errors.New("unknown prepared run format")
@@ -26,7 +26,7 @@ const (
 
 // PreparedRunFormatter serializes a prepared run without performing use case work.
 type PreparedRunFormatter interface {
-	Format(prepared *domain.PreparedRun) ([]byte, error)
+	Format(prepared *scriptorium.PreparedRun) ([]byte, error)
 }
 
 // ParsePreparedRunOutputFormat parses a format name.
@@ -56,7 +56,7 @@ func FormatterForPreparedRun(outputFormat PreparedRunOutputFormat) (PreparedRunF
 }
 
 // FormatPreparedRun formats a prepared run using the selected format.
-func FormatPreparedRun(prepared *domain.PreparedRun, outputFormat PreparedRunOutputFormat) ([]byte, error) {
+func FormatPreparedRun(prepared *scriptorium.PreparedRun, outputFormat PreparedRunOutputFormat) ([]byte, error) {
 	formatter, err := FormatterForPreparedRun(outputFormat)
 	if err != nil {
 		return nil, err
@@ -65,7 +65,7 @@ func FormatPreparedRun(prepared *domain.PreparedRun, outputFormat PreparedRunOut
 }
 
 // FormatPreparedRunByName parses a format name and formats a prepared run.
-func FormatPreparedRunByName(prepared *domain.PreparedRun, rawFormat string) ([]byte, error) {
+func FormatPreparedRunByName(prepared *scriptorium.PreparedRun, rawFormat string) ([]byte, error) {
 	outputFormat, err := ParsePreparedRunOutputFormat(rawFormat)
 	if err != nil {
 		return nil, err
@@ -75,7 +75,7 @@ func FormatPreparedRunByName(prepared *domain.PreparedRun, rawFormat string) ([]
 
 type jsonPreparedRunFormatter struct{}
 
-func (jsonPreparedRunFormatter) Format(prepared *domain.PreparedRun) ([]byte, error) {
+func (jsonPreparedRunFormatter) Format(prepared *scriptorium.PreparedRun) ([]byte, error) {
 	if prepared == nil {
 		return nil, errors.New("prepared run is nil")
 	}
@@ -84,7 +84,7 @@ func (jsonPreparedRunFormatter) Format(prepared *domain.PreparedRun) ([]byte, er
 
 type textPreparedRunFormatter struct{}
 
-func (textPreparedRunFormatter) Format(prepared *domain.PreparedRun) ([]byte, error) {
+func (textPreparedRunFormatter) Format(prepared *scriptorium.PreparedRun) ([]byte, error) {
 	if prepared == nil {
 		return nil, errors.New("prepared run is nil")
 	}
@@ -146,7 +146,7 @@ func (textPreparedRunFormatter) Format(prepared *domain.PreparedRun) ([]byte, er
 
 	fmt.Fprintln(&b, "messages:")
 	roleOrder := make([]string, 0)
-	byRole := make(map[string][]domain.RenderedMessage)
+	byRole := make(map[string][]scriptorium.RenderedMessage)
 	for _, msg := range prepared.Messages {
 		if _, exists := byRole[msg.Role]; !exists {
 			roleOrder = append(roleOrder, msg.Role)

internal/format/prepared_run_test.go

@@ -6,7 +6,7 @@ import (
 	"strings"
 	"testing"
 
-	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
+	"gitea.maximumdirect.net/eric/scriptorium"
 )
 
 func TestTextFormatterIncludesPreparedRunDetails(t *testing.T) {
@@ -94,9 +94,8 @@ func TestTextFormatterDoesNotIncludeResolvedAPIKeyValue(t *testing.T) {
 
 func TestTextFormatterDoesNotIncludeDirectAPIKeyValue(t *testing.T) {
 	const directKey = "direct-format-key"
+	// PreparedRun intentionally has no field for direct API keys.
 	prepared := samplePreparedRun()
-	prepared.EffectiveModelParams.APIKey = directKey
-
 	out, err := FormatPreparedRun(prepared, PreparedRunFormatText)
 	if err != nil {
 		t.Fatalf("expected no error, got %v", err)
@@ -108,12 +107,12 @@ func TestTextFormatterDoesNotIncludeDirectAPIKeyValue(t *testing.T) {
 
 func TestTextFormatterIncludesMessageCacheControlBeforeContent(t *testing.T) {
 	prepared := samplePreparedRun()
-	prepared.Messages = []domain.RenderedMessage{
+	prepared.Messages = []scriptorium.RenderedMessage{
 		{
 			Role:    "system",
 			Content: "System guidance.",
-			CacheControl: &domain.CacheControl{
-				Type: domain.CacheControlEphemeral,
+			CacheControl: &scriptorium.CacheControl{
+				Type: scriptorium.CacheControlEphemeral,
 				TTL:  "1h",
 			},
 		},
@@ -148,12 +147,12 @@ func TestTextFormatterIncludesSessionIDWhenPresent(t *testing.T) {
 
 func TestTextFormatterOmitsEmptyCacheControlTTL(t *testing.T) {
 	prepared := samplePreparedRun()
-	prepared.Messages = []domain.RenderedMessage{
+	prepared.Messages = []scriptorium.RenderedMessage{
 		{
 			Role:    "system",
 			Content: "System guidance.",
-			CacheControl: &domain.CacheControl{
-				Type: domain.CacheControlEphemeral,
+			CacheControl: &scriptorium.CacheControl{
+				Type: scriptorium.CacheControlEphemeral,
 			},
 		},
 	}
@@ -231,12 +230,12 @@ func TestJSONFormatterEmitsValidJSONAndIncludesPreparedRunFields(t *testing.T) {
 
 func TestJSONFormatterIncludesMessageCacheControlOnlyWhenPresent(t *testing.T) {
 	prepared := samplePreparedRun()
-	prepared.Messages = []domain.RenderedMessage{
+	prepared.Messages = []scriptorium.RenderedMessage{
 		{
 			Role:    "system",
 			Content: "System guidance.",
-			CacheControl: &domain.CacheControl{
-				Type: domain.CacheControlEphemeral,
+			CacheControl: &scriptorium.CacheControl{
+				Type: scriptorium.CacheControlEphemeral,
 				TTL:  "1h",
 			},
 		},
@@ -262,7 +261,7 @@ func TestJSONFormatterIncludesMessageCacheControlOnlyWhenPresent(t *testing.T) {
 	if !ok {
 		t.Fatalf("expected first message cache_control, got %#v", decoded.Messages[0])
 	}
-	if cacheControl["type"] != string(domain.CacheControlEphemeral) || cacheControl["ttl"] != "1h" {
+	if cacheControl["type"] != string(scriptorium.CacheControlEphemeral) || cacheControl["ttl"] != "1h" {
 		t.Fatalf("unexpected cache_control payload: %#v", cacheControl)
 	}
 	if _, ok := decoded.Messages[1]["cache_control"]; ok {
@@ -285,9 +284,8 @@ func TestJSONFormatterDoesNotIncludeResolvedAPIKeyValue(t *testing.T) {
 
 func TestJSONFormatterDoesNotIncludeDirectAPIKeyValue(t *testing.T) {
 	const directKey = "direct-format-key"
+	// PreparedRun intentionally has no field for direct API keys.
 	prepared := samplePreparedRun()
-	prepared.EffectiveModelParams.APIKey = directKey
-
 	out, err := FormatPreparedRun(prepared, PreparedRunFormatJSON)
 	if err != nil {
 		t.Fatalf("expected no error, got %v", err)
@@ -342,13 +340,13 @@ func TestFormatPreparedRunByNameUnknownFailsClearly(t *testing.T) {
 	}
 }
 
-func samplePreparedRun() *domain.PreparedRun {
-	return &domain.PreparedRun{
+func samplePreparedRun() *scriptorium.PreparedRun {
+	return &scriptorium.PreparedRun{
 		PromptID:          "prompt.id",
 		PromptVersion:     "v1",
 		PromptHash:        "prompt-hash",
 		SelectedProfileID: "local-fast",
-		EffectiveModelParams: domain.ExecutionTarget{
+		EffectiveModelParams: scriptorium.ExecutionTarget{
 			Endpoint:        "http://llm/v1",
 			Model:           "gpt-test",
 			Temperature:     0.4,
@@ -364,7 +362,7 @@ func samplePreparedRun() *domain.PreparedRun {
 			"glossary":   "hash-glossary",
 		},
 		RenderedPromptHash: "rendered-hash",
-		Messages: []domain.RenderedMessage{
+		Messages: []scriptorium.RenderedMessage{
 			{Role: "system", Content: "System guidance."},
 			{Role: "user", Content: "Summarize the transcript.\nInclude key entities."},
 			{Role: "user", Content: "Second user message."},

types.go

@@ -126,6 +126,14 @@ type Artifact struct {
 	Hash        string
 }
 
+// ArtifactReader resolves a prompt input reference into its content.
+//
+// Readers are responsible for supplying artifact metadata. The engine assigns
+// an input-map name only when the returned artifact name is empty.
+type ArtifactReader interface {
+	Read(context.Context, ArtifactRef) (*Artifact, error)
+}
+
 // ExecutionTarget represents effective model runtime settings.
 type ExecutionTarget struct {
 	Endpoint        string         `json:"endpoint"`