Make GoDoc the public API contract

This commit is contained in:
2026-07-29 14:06:54 +00:00
parent c1cecb1ee8
commit 086cf0fc86
10 changed files with 798 additions and 359 deletions

165
engine.go
View File

@@ -22,42 +22,93 @@ import (
"gitea.maximumdirect.net/eric/promptkit/internal/validate"
)
// ErrInvalidConfig indicates invalid public engine configuration.
// ErrInvalidConfig identifies invalid engine construction, including missing
// required configuration, invalid options, and a nil Engine receiver.
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")
ErrProfileRequired = errors.New("profile selection is required")
ErrPromptLoad = errors.New("failed to load prompt definition")
ErrProfileLoad = errors.New("failed to load execution profile")
// ErrInvalidRequest identifies a request whose required values, overrides,
// credentials, or effective settings are invalid.
ErrInvalidRequest = errors.New("invalid run request")
// ErrPromptNotFound identifies a requested prompt ID or version that is not
// present in the selected prompt source. It does not also match
// ErrPromptLoad.
ErrPromptNotFound = errors.New("prompt not found")
// ErrProfileNotFound identifies a selected profile ID that is absent from
// every configured profile source. It does not also match ErrProfileLoad.
ErrProfileNotFound = errors.New("profile not found")
// ErrProfileRequired identifies a request for which neither RunRequest.ProfileID
// nor the selected prompt's default profile is present. Such an error also
// matches ErrInvalidRequest.
ErrProfileRequired = errors.New("profile selection is required")
// ErrPromptLoad identifies a failure to read, decode, validate, select, or
// hash a prompt definition, except for the not-found case represented by
// ErrPromptNotFound.
ErrPromptLoad = errors.New("failed to load prompt definition")
// ErrProfileLoad identifies a failure to read, decode, validate, or select
// an execution profile, except for the not-found case represented by
// ErrProfileNotFound.
ErrProfileLoad = errors.New("failed to load execution profile")
// ErrAPIKeyEnvMissing identifies an APIKeyEnv whose environment variable is
// unset or empty when no direct RunRequest.APIKey takes precedence. Such an
// error also matches ErrInvalidRequest.
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")
// ErrArtifactLoad identifies a failure to resolve an input artifact. Errors
// returned by an injected ArtifactReader remain available through errors.Is.
ErrArtifactLoad = errors.New("failed to load artifact")
// ErrPromptRender identifies a failure to render prompt messages or the
// session ID from the resolved inputs and variables.
ErrPromptRender = errors.New("failed to render prompt")
// ErrLLMGenerate identifies a model-client failure or a nil successful
// response. Errors returned by an injected LLMClient remain available
// through errors.Is.
ErrLLMGenerate = errors.New("failed to generate output")
// ErrValidation identifies an operational failure to load or compile a
// schema or validate output. A completed validation whose Status is
// ValidationFailed is returned in RunResult without this error.
ErrValidation = errors.New("failed to validate output")
)
// Engine prepares and runs Promptkit prompt requests.
//
// An Engine is safe for concurrent calls to [Engine.Prepare] and [Engine.Run].
// Injected collaborators may consequently be invoked concurrently.
type Engine struct {
runner *usecase.Runner
}
// Config configures a public Promptkit engine.
// Config selects the directory-backed sources and built-in model-client
// transport used by [NewEngine]. Config has no stable JSON representation.
type Config struct {
PromptDir string
// PromptDir is the directory searched recursively for prompt definitions.
// It is required unless a WithPromptFS or WithPromptFile option supplies the
// prompt source.
PromptDir string
// ProfileDir is an optional directory whose profiles take precedence over
// embedded built-in profiles. An empty value selects only built-ins unless
// profile options are also supplied.
ProfileDir string
SchemaDir string
// SchemaDir is the root for JSON Schema files. An empty value uses the
// current directory. WithSchemaFS or WithSchemaFile replaces this source.
SchemaDir string
// Timeout is the transport-wide safety cap for the built-in LLM client
// when HTTPClient is absent or has a non-positive timeout.
// when HTTPClient is absent or has a non-positive timeout. A zero or negative
// value selects the 10-minute default.
Timeout time.Duration
// HTTPClient is cloned for the built-in LLM client. Its positive Timeout
// takes precedence over Config.Timeout as the transport-wide safety cap.
// takes precedence over Timeout. A zero or negative client Timeout inherits
// Timeout or the 10-minute default. The supplied client is not mutated. This
// field is ignored when WithLLMClient is used.
HTTPClient *http.Client
}
// Option customizes engine construction.
//
// NewEngine applies options in argument order and ignores nil options. Within
// each prompt-source, profile-source, in-memory-profile, schema-source,
// model-client, and artifact-reader category, the last non-nil valid option
// replaces earlier options in that category. An invalid option fails
// construction even if a later option would replace it.
type Option interface {
apply(*engineOptions) error
}
@@ -82,7 +133,10 @@ type engineOptions struct {
artifactSource bool
}
// WithLLMClient injects a custom LLM client for execution.
// WithLLMClient replaces the built-in model client used by [Engine.Run].
//
// A nil client makes NewEngine fail with ErrInvalidConfig. The client may be
// called concurrently and is not used by [Engine.Prepare].
func WithLLMClient(client LLMClient) Option {
return optionFunc(func(options *engineOptions) error {
if client == nil {
@@ -93,7 +147,11 @@ func WithLLMClient(client LLMClient) Option {
})
}
// WithArtifactReader injects a reader for every input artifact reference.
// WithArtifactReader replaces the default reader for every input artifact
// reference, regardless of its ArtifactRef.Type.
//
// A nil reader makes NewEngine fail with ErrInvalidConfig. The reader may be
// called concurrently.
func WithArtifactReader(reader ArtifactReader) Option {
return optionFunc(func(options *engineOptions) error {
if reader == nil {
@@ -109,6 +167,9 @@ func WithArtifactReader(reader ArtifactReader) Option {
//
// The source uses the same strict prompt YAML rules as configured prompt
// directories, and prompt content_file paths resolve within this source.
// fsys must be non-nil and root must be non-empty; otherwise NewEngine fails
// with ErrInvalidConfig. This option replaces Config.PromptDir and earlier
// prompt-source options.
func WithPromptFS(fsys fs.FS, root string) Option {
return optionFunc(func(options *engineOptions) error {
if fsys == nil {
@@ -125,7 +186,9 @@ func WithPromptFS(fsys fs.FS, root string) Option {
// WithPromptFile loads prompt definitions from the single prompt file at path.
//
// Relative prompt content_file paths resolve from the file's directory.
// Relative prompt content_file paths resolve from the file's directory. path
// must name an existing non-directory file when NewEngine applies the option.
// This option replaces Config.PromptDir and earlier prompt-source options.
func WithPromptFile(path string) Option {
return optionFunc(func(options *engineOptions) error {
fsys, root, err := fileSource(path)
@@ -142,6 +205,10 @@ func WithPromptFile(path string) Option {
//
// Profiles from this source overlay built-in profiles. Profile YAML must use
// api_key_env for environment-based credentials; raw API keys are rejected.
// fsys must be non-nil and root must be non-empty; otherwise NewEngine fails
// with ErrInvalidConfig. This option replaces Config.ProfileDir and earlier
// file or FS profile-source options, but remains below WithProfiles in
// precedence.
func WithProfileFS(fsys fs.FS, root string) Option {
return optionFunc(func(options *engineOptions) error {
if fsys == nil {
@@ -159,7 +226,10 @@ func WithProfileFS(fsys fs.FS, root string) Option {
// WithProfileFile loads execution profiles from the single profile file at path.
//
// The profile overlays built-in profiles. Profile YAML must use api_key_env for
// environment-based credentials; raw API keys are rejected.
// environment-based credentials; raw API keys are rejected. path must name an
// existing non-directory file when NewEngine applies the option. This option
// replaces Config.ProfileDir and earlier file or FS profile-source options,
// but remains below WithProfiles in precedence.
func WithProfileFile(path string) Option {
return optionFunc(func(options *engineOptions) error {
fsys, root, err := fileSource(path)
@@ -174,6 +244,11 @@ func WithProfileFile(path string) Option {
// WithProfiles configures in-memory profiles that take precedence over
// configured profile files and built-in profiles.
//
// NewEngine validates and copies every profile. IDs must be unique within one
// call. An invalid profile, duplicate ID, or unsupported ExtraParams value
// makes construction fail with ErrInvalidConfig. Repeating WithProfiles
// replaces the complete earlier in-memory set rather than merging it.
func WithProfiles(profiles ...Profile) Option {
return optionFunc(func(options *engineOptions) error {
repo, err := newMemoryProfileRepository(profiles)
@@ -189,7 +264,9 @@ func WithProfiles(profiles ...Profile) Option {
// WithSchemaFS loads JSON Schema documents from fsys under root.
//
// Prompt schema_path values resolve within this source when schema validation
// or structured output is requested.
// or structured output is requested. fsys must be non-nil and root must be
// non-empty; otherwise NewEngine fails with ErrInvalidConfig. This option
// replaces Config.SchemaDir and earlier schema-source options.
func WithSchemaFS(fsys fs.FS, root string) Option {
return optionFunc(func(options *engineOptions) error {
if fsys == nil {
@@ -206,7 +283,9 @@ func WithSchemaFS(fsys fs.FS, root string) Option {
// WithSchemaFile loads JSON Schema documents from the single schema file at path.
//
// Prompt schema_path values refer to the file's base name.
// Prompt schema_path values refer to the file's base name. path must name an
// existing non-directory file when NewEngine applies the option. This option
// replaces Config.SchemaDir and earlier schema-source options.
func WithSchemaFile(path string) Option {
return optionFunc(func(options *engineOptions) error {
fsys, root, err := fileSource(path)
@@ -220,6 +299,15 @@ func WithSchemaFile(path string) Option {
}
// NewEngine constructs an Engine from configuration and options.
//
// Options are applied in order according to [Option]. PromptDir is required
// unless a prompt-source option is present. Construction validates option
// arguments and in-memory profiles but defers reading and validating prompt,
// file-backed profile, and schema contents until Prepare or Run needs them.
//
// NewEngine returns an error matching ErrInvalidConfig for invalid
// configuration or options. It does not perform model requests or require
// credentials.
func NewEngine(cfg Config, opts ...Option) (*Engine, error) {
var options engineOptions
for _, opt := range opts {
@@ -305,7 +393,22 @@ func fileSource(name string) (fs.FS, string, error) {
return os.DirFS(dir), filepath.ToSlash(base), nil
}
// Prepare resolves a prompt request without calling an LLM.
// Prepare resolves and renders a prompt request without calling an LLM.
//
// Prepare selects the prompt and profile, resolves effective execution
// settings and the output contract, loads and hashes inputs, loads structured
// output schema metadata when required, and renders the session ID and
// messages. The returned PreparedRun is owned by the caller and never contains
// a resolved API-key value, model output, or validation result.
//
// A nil Engine returns an error matching ErrInvalidConfig. Request and
// preparation failures may match ErrInvalidRequest, ErrPromptNotFound,
// ErrPromptLoad, ErrProfileNotFound, ErrProfileLoad, ErrProfileRequired,
// ErrAPIKeyEnvMissing, ErrArtifactLoad, ErrPromptRender, or ErrValidation as
// applicable. Cancellation is passed to the active collaborator and is
// reported in the applicable operation category; no general errors.Is
// relationship to ctx.Err is promised. Prepare returns no partial result on
// error.
func (e *Engine) Prepare(ctx context.Context, req RunRequest) (*PreparedRun, error) {
if e == nil || e.runner == nil {
return nil, fmt.Errorf("%w: engine is nil", ErrInvalidConfig)
@@ -323,7 +426,21 @@ func (e *Engine) Prepare(ctx context.Context, req RunRequest) (*PreparedRun, err
return fromDomainPreparedRun(prepared), nil
}
// Run executes a prompt request and returns the generated artifact and metadata.
// Run prepares a request, invokes the configured LLMClient, and validates the
// generated output.
//
// A content-validation failure is a successful run whose
// RunResult.Validation has Status ValidationFailed. An inability to perform
// validation returns an error matching ErrValidation and no partial result.
// The public Engine does not perform output repair, so validation is
// single-pass even when OutputContract.RepairAttempts is positive.
//
// Run can return every error category documented by [Engine.Prepare], plus
// ErrLLMGenerate. Errors from injected clients remain available through
// errors.Is. Cancellation is passed through the active collaborator and is
// reported in the applicable operation category; no general errors.Is
// relationship to ctx.Err is promised. A nil Engine returns ErrInvalidConfig.
// Run returns no partial result on error.
func (e *Engine) Run(ctx context.Context, req RunRequest) (*RunResult, error) {
if e == nil || e.runner == nil {
return nil, fmt.Errorf("%w: engine is nil", ErrInvalidConfig)