adk

package
v0.6.0 Latest Latest
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 Go to latest Published: Mar 17, 2026 License: MIT Imports: 33 Imported by: 0

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Index

Constants

View Source 
const DefaultTokenBudget = 32000

DefaultTokenBudget is the token budget used when no explicit budget is provided.

Variables

This section is empty.

Functions

func AdaptTool 

func AdaptTool(t *agent.Tool) (tool.Tool, error)

AdaptTool converts an internal agent.Tool to an ADK tool.Tool.

func AdaptToolForAgent added in v0.4.0 

func AdaptToolForAgent(t *agent.Tool, agentName string) (tool.Tool, error)

AdaptToolForAgent converts an internal agent.Tool to an ADK tool.Tool and injects the given agentName into the context for every handler invocation. This allows downstream hooks and middleware to identify which agent owns the tool call.

func AdaptToolForAgentWithTimeout added in v0.4.0 

func AdaptToolForAgentWithTimeout(t *agent.Tool, agentName string, timeout time.Duration) (tool.Tool, error)

AdaptToolForAgentWithTimeout combines agent name injection with a per-call timeout.

func AdaptToolWithTimeout 

func AdaptToolWithTimeout(t *agent.Tool, timeout time.Duration) (tool.Tool, error)

AdaptToolWithTimeout converts an internal agent.Tool to an ADK tool.Tool with an enforced per-call timeout. If timeout <= 0, behaves like AdaptTool.

func AgentNameFromContext added in v0.4.0 

func AgentNameFromContext(ctx context.Context) string

AgentNameFromContext extracts the agent name stored in ctx. Returns an empty string when no agent name is present.

func ModelTokenBudget 

func ModelTokenBudget(modelName string) int

ModelTokenBudget returns an appropriate history token budget for the given model. It uses approximately 50-60% of each model family's context window, leaving room for system prompts, tool definitions, and generated output. Returns DefaultTokenBudget for unknown models.

func WithAgentName added in v0.4.0 

func WithAgentName(ctx context.Context, name string) context.Context

WithAgentName returns a context carrying the given agent name. This delegates to ctxkeys.WithAgentName so that any package importing ctxkeys can read the value without depending on the adk package.

func WithChildSession added in v0.4.0 

func WithChildSession(ctx context.Context, info ChildSessionInfo) context.Context

WithChildSession stores child session info in context.

Types

type Agent 

type Agent struct {
	// contains filtered or unexported fields
}

Agent wraps the ADK runner for integration with Lango.

func NewAgent 

func NewAgent(ctx context.Context, tools []tool.Tool, mod model.LLM, systemPrompt string, store internal.Store, opts ...AgentOption) (*Agent, error)

NewAgent creates a new Agent instance.

func NewAgentFromADK 

func NewAgentFromADK(adkAgent adk_agent.Agent, store internal.Store, opts ...AgentOption) (*Agent, error)

NewAgentFromADK creates a Lango Agent wrapping a pre-built ADK agent. Used for multi-agent orchestration where the agent tree is built externally.

func (*Agent) ADKAgent 

func (a *Agent) ADKAgent() adk_agent.Agent

ADKAgent returns the underlying ADK agent, or nil if not available.

func (*Agent) Run 

func (a *Agent) Run(ctx context.Context, sessionID string, input string) iter.Seq2[*session.Event, error]

Run executes the agent for a given session and returns an event iterator. It enforces a maximum turn limit to prevent unbounded tool-calling loops.

func (*Agent) RunAndCollect 

func (a *Agent) RunAndCollect(ctx context.Context, sessionID, input string, opts ...RunOption) (string, error)

RunAndCollect executes the agent and returns the full text response. If the agent encounters a "failed to find agent" error (hallucinated agent name), it sends a correction message and retries once.

func (*Agent) RunStreaming 

func (a *Agent) RunStreaming(ctx context.Context, sessionID, input string, onChunk ChunkCallback, opts ...RunOption) (string, error)

RunStreaming executes the agent and streams partial text chunks via the callback. It returns the full accumulated response text for backward compatibility.

func (*Agent) WithErrorFixProvider 

func (a *Agent) WithErrorFixProvider(p ErrorFixProvider) *Agent

WithErrorFixProvider sets an optional provider for learning-based error correction. When set, the agent will attempt to apply known fixes on errors before giving up.

func (*Agent) WithMaxTurns 

func (a *Agent) WithMaxTurns(n int) *Agent

WithMaxTurns sets the maximum number of tool-calling turns per run. Zero or negative values use the default (25).

type AgentError added in v0.5.0 

type AgentError struct {
	Code    ErrorCode
	Message string        // internal message
	Cause   error         // underlying error
	Partial string        // accumulated text before failure
	Elapsed time.Duration // time spent before failure
}

AgentError is a structured error type that preserves partial results accumulated before the failure, along with classification metadata.

func (*AgentError) Error added in v0.5.0 

func (e *AgentError) Error() string

func (*AgentError) Unwrap added in v0.5.0 

func (e *AgentError) Unwrap() error

func (*AgentError) UserMessage added in v0.5.0 

func (e *AgentError) UserMessage() string

UserMessage returns a user-facing formatted message with error code and hint.

type AgentOption 

type AgentOption func(*agentOptions)

AgentOption configures optional Agent behavior at construction time.

func WithAgentErrorFixProvider 

func WithAgentErrorFixProvider(p ErrorFixProvider) AgentOption

WithAgentErrorFixProvider sets a learning-based error correction provider.

func WithAgentMaxTurns 

func WithAgentMaxTurns(n int) AgentOption

WithAgentMaxTurns sets the maximum number of tool-calling turns per run.

func WithAgentTokenBudget 

func WithAgentTokenBudget(budget int) AgentOption

WithAgentTokenBudget sets the session history token budget. Use ModelTokenBudget(modelName) to derive an appropriate value.

type ChildSessionInfo added in v0.4.0 

type ChildSessionInfo struct {
	ChildKey  string
	ParentKey string
	AgentName string
}

ChildSessionInfo holds child session metadata in context.

func ChildSessionFromContext added in v0.4.0 

func ChildSessionFromContext(ctx context.Context) (ChildSessionInfo, bool)

ChildSessionFromContext retrieves child session info from context.

type ChildSessionServiceAdapter added in v0.4.0 

type ChildSessionServiceAdapter struct {
	// contains filtered or unexported fields
}

ChildSessionServiceAdapter wraps a ChildSessionStore to provide fork/merge/discard operations integrated with ADK's session management.

func NewChildSessionServiceAdapter added in v0.4.0 

func NewChildSessionServiceAdapter(childStore session.ChildSessionStore, summarizer Summarizer) *ChildSessionServiceAdapter

NewChildSessionServiceAdapter creates a new adapter.

func (*ChildSessionServiceAdapter) Discard added in v0.4.0 

func (a *ChildSessionServiceAdapter) Discard(childKey string) error

Discard removes a child session without merging.

func (*ChildSessionServiceAdapter) Fork added in v0.4.0 

func (a *ChildSessionServiceAdapter) Fork(parentKey, agentName string, cfg session.ChildSessionConfig) (*session.ChildSession, error)

Fork creates a child session for a sub-agent.

func (*ChildSessionServiceAdapter) MergeWithSummary added in v0.4.0 

func (a *ChildSessionServiceAdapter) MergeWithSummary(childKey string) error

MergeWithSummary merges a child session using the configured summarizer.

type ChunkCallback 

type ChunkCallback func(chunk string)

ChunkCallback is called for each streaming text chunk during agent execution.

type ContextAwareModelAdapter 

type ContextAwareModelAdapter struct {
	// contains filtered or unexported fields
}

ContextAwareModelAdapter wraps a ModelAdapter with context retrieval. Before each LLM call, it retrieves relevant knowledge and injects it into the system instruction.

func NewContextAwareModelAdapter 

func NewContextAwareModelAdapter(
	inner *ModelAdapter,
	retriever *knowledge.ContextRetriever,
	builder *prompt.Builder,
	logger *zap.SugaredLogger,
) *ContextAwareModelAdapter

NewContextAwareModelAdapter creates a context-aware model adapter. The builder is used to produce the base system prompt; dynamic context (knowledge, memory, RAG) is still appended at call time.

func (*ContextAwareModelAdapter) GenerateContent 

func (m *ContextAwareModelAdapter) GenerateContent(ctx context.Context, req *model.LLMRequest, stream bool) iter.Seq2[*model.LLMResponse, error]

GenerateContent retrieves context and injects an augmented system prompt before delegating to the inner adapter.

func (*ContextAwareModelAdapter) Name 

func (m *ContextAwareModelAdapter) Name() string

Name delegates to the inner adapter.

func (*ContextAwareModelAdapter) WithGraphRAG 

func (m *ContextAwareModelAdapter) WithGraphRAG(svc *graph.GraphRAGService) *ContextAwareModelAdapter

WithGraphRAG adds graph-enhanced RAG support. When set, graph expansion is performed on vector search results to discover structurally connected context.

func (*ContextAwareModelAdapter) WithMemory 

func (m *ContextAwareModelAdapter) WithMemory(provider MemoryProvider) *ContextAwareModelAdapter

WithMemory adds observational memory support to the adapter. The session key is resolved at call time from the request context via session.SessionKeyFromContext.

func (*ContextAwareModelAdapter) WithMemoryLimits 

func (m *ContextAwareModelAdapter) WithMemoryLimits(maxReflections, maxObservations int) *ContextAwareModelAdapter

WithMemoryLimits sets the maximum number of reflections and observations to include in the LLM context. Zero means unlimited (existing behavior).

func (*ContextAwareModelAdapter) WithMemoryTokenBudget 

func (m *ContextAwareModelAdapter) WithMemoryTokenBudget(budget int) *ContextAwareModelAdapter

WithMemoryTokenBudget sets the maximum token budget for the memory section injected into the system prompt. Reflections are prioritized first (higher information density), then observations fill the remaining budget. Zero means use default (4000 tokens).

func (*ContextAwareModelAdapter) WithRAG 

func (m *ContextAwareModelAdapter) WithRAG(svc *embedding.RAGService, opts embedding.RetrieveOptions) *ContextAwareModelAdapter

WithRAG adds RAG (retrieval-augmented generation) support.

func (*ContextAwareModelAdapter) WithRuntimeAdapter 

func (m *ContextAwareModelAdapter) WithRuntimeAdapter(adapter *RuntimeContextAdapter) *ContextAwareModelAdapter

WithRuntimeAdapter adds runtime context support to the adapter.

type ErrorCode added in v0.5.0 

type ErrorCode string

ErrorCode identifies the category of an agent error. 

const (
	ErrTimeout     ErrorCode = "E001"
	ErrModelError  ErrorCode = "E002"
	ErrToolError   ErrorCode = "E003"
	ErrTurnLimit   ErrorCode = "E004"
	ErrInternal    ErrorCode = "E005"
	ErrIdleTimeout ErrorCode = "E006"
)

type ErrorFixProvider 

type ErrorFixProvider interface {
	GetFixForError(ctx context.Context, toolName string, err error) (string, bool)
}

ErrorFixProvider returns a known fix for a tool error if one exists. Implemented by learning.Engine.

type EventsAdapter 

type EventsAdapter struct {
	// contains filtered or unexported fields
}

EventsAdapter adapts internal history to adk events. Uses token-budget truncation: includes messages from most recent until the budget is exhausted. Truncated history and converted events are lazily cached for O(1) repeated access.

func (*EventsAdapter) All 

func (e *EventsAdapter) All() iter.Seq[*session.Event]

func (*EventsAdapter) At 

func (e *EventsAdapter) At(i int) *session.Event

At returns the i-th event. The full event list is built once on first call and cached, making subsequent At calls O(1) instead of O(n).

func (*EventsAdapter) Len 

func (e *EventsAdapter) Len() int

type MemoryProvider 

type MemoryProvider interface {
	ListObservations(ctx context.Context, sessionKey string) ([]memory.Observation, error)
	ListReflections(ctx context.Context, sessionKey string) ([]memory.Reflection, error)
	ListRecentReflections(ctx context.Context, sessionKey string, limit int) ([]memory.Reflection, error)
	ListRecentObservations(ctx context.Context, sessionKey string, limit int) ([]memory.Observation, error)
}

MemoryProvider retrieves observations and reflections for a session.

type ModelAdapter 

type ModelAdapter struct {
	OnTokenUsage TokenUsageCallback
	// contains filtered or unexported fields
}

func NewModelAdapter 

func NewModelAdapter(p provider.Provider, model string) *ModelAdapter

func (*ModelAdapter) GenerateContent 

func (m *ModelAdapter) GenerateContent(ctx context.Context, req *model.LLMRequest, stream bool) iter.Seq2[*model.LLMResponse, error]

func (*ModelAdapter) Name 

func (m *ModelAdapter) Name() string

type PIIRedactingModelAdapter 

type PIIRedactingModelAdapter struct {
	// contains filtered or unexported fields
}

PIIRedactingModelAdapter wraps an LLM and redacts PII from user messages before forwarding them to the underlying model. It also scans tool results and model responses for known secret values.

func NewPIIRedactingModelAdapter 

func NewPIIRedactingModelAdapter(
	inner model.LLM,
	redactor *agent.PIIRedactor,
	scanner *agent.SecretScanner,
) *PIIRedactingModelAdapter

NewPIIRedactingModelAdapter creates a PII-redacting model adapter. If scanner is nil, output scanning is disabled.

func (*PIIRedactingModelAdapter) GenerateContent 

func (m *PIIRedactingModelAdapter) GenerateContent(
	ctx context.Context,
	req *model.LLMRequest,
	stream bool,
) iter.Seq2[*model.LLMResponse, error]

GenerateContent redacts PII from user messages, scans tool results for secrets, and wraps the response iterator to scan model output.

func (*PIIRedactingModelAdapter) Name 

func (m *PIIRedactingModelAdapter) Name() string

Name delegates to the inner adapter.

type RunOption added in v0.5.0 

type RunOption func(*runOptions)

RunOption configures optional behavior for a single agent run.

func WithOnActivity added in v0.5.0 

func WithOnActivity(fn func()) RunOption

WithOnActivity sets a callback that is invoked whenever the agent produces activity (text chunks, function calls). Useful for extending deadlines.

type RuntimeContextAdapter 

type RuntimeContextAdapter struct {
	// contains filtered or unexported fields
}

RuntimeContextAdapter provides runtime session/system state.

func NewRuntimeContextAdapter 

func NewRuntimeContextAdapter(toolCount int, encryption, knowledgeEnabled, memoryEnabled bool) *RuntimeContextAdapter

NewRuntimeContextAdapter creates a RuntimeContextAdapter with static system info.

func (*RuntimeContextAdapter) GetRuntimeContext 

func (a *RuntimeContextAdapter) GetRuntimeContext() knowledge.RuntimeContext

GetRuntimeContext returns a snapshot of the current runtime context.

func (*RuntimeContextAdapter) SetSession 

func (a *RuntimeContextAdapter) SetSession(sessionKey string)

SetSession updates the session key and derives the channel type.

type SessionAdapter 

type SessionAdapter struct {
	// contains filtered or unexported fields
}

SessionAdapter adapts internal.Session to adk.Session

func NewSessionAdapter 

func NewSessionAdapter(s *internal.Session, store internal.Store, rootAgentName string) *SessionAdapter

func (*SessionAdapter) AppName 

func (s *SessionAdapter) AppName() string

func (*SessionAdapter) Events 

func (s *SessionAdapter) Events() session.Events

func (*SessionAdapter) EventsWithTokenBudget 

func (s *SessionAdapter) EventsWithTokenBudget(budget int) session.Events

EventsWithTokenBudget returns an EventsAdapter that uses token-budget truncation.

func (*SessionAdapter) ID 

func (s *SessionAdapter) ID() string

func (*SessionAdapter) LastUpdateTime 

func (s *SessionAdapter) LastUpdateTime() time.Time

func (*SessionAdapter) State 

func (s *SessionAdapter) State() session.State

func (*SessionAdapter) UserID 

func (s *SessionAdapter) UserID() string

type SessionServiceAdapter 

type SessionServiceAdapter struct {
	// contains filtered or unexported fields
}

func NewSessionServiceAdapter 

func NewSessionServiceAdapter(store internal.Store, rootAgentName string) *SessionServiceAdapter

func (*SessionServiceAdapter) AppendEvent 

func (s *SessionServiceAdapter) AppendEvent(ctx context.Context, sess session.Session, evt *session.Event) error

func (*SessionServiceAdapter) Create 

func (s *SessionServiceAdapter) Create(ctx context.Context, req *session.CreateRequest) (*session.CreateResponse, error)

func (*SessionServiceAdapter) Delete 

func (s *SessionServiceAdapter) Delete(ctx context.Context, req *session.DeleteRequest) error

func (*SessionServiceAdapter) Get 

func (s *SessionServiceAdapter) Get(ctx context.Context, req *session.GetRequest) (*session.GetResponse, error)

func (*SessionServiceAdapter) List 

func (s *SessionServiceAdapter) List(ctx context.Context, req *session.ListRequest) (*session.ListResponse, error)

func (*SessionServiceAdapter) WithTokenBudget 

func (s *SessionServiceAdapter) WithTokenBudget(budget int) *SessionServiceAdapter

WithTokenBudget sets the token budget for history truncation. Use ModelTokenBudget(modelName) to derive an appropriate budget from the model name.

type StateAdapter 

type StateAdapter struct {
	// contains filtered or unexported fields
}

StateAdapter adapts internal.Session.Metadata to adk.State

func (*StateAdapter) All 

func (s *StateAdapter) All() iter.Seq2[string, any]

func (*StateAdapter) Get 

func (s *StateAdapter) Get(key string) (any, error)

func (*StateAdapter) Set 

func (s *StateAdapter) Set(key string, val any) error

type StructuredSummarizer added in v0.4.0 

type StructuredSummarizer struct{}

StructuredSummarizer extracts the last assistant response as the summary. This is the default zero-cost summarizer that avoids LLM calls.

func (*StructuredSummarizer) Summarize added in v0.4.0 

func (s *StructuredSummarizer) Summarize(messages []session.Message) (string, error)

Summarize returns the last assistant message content as the summary. If no assistant message is found, returns an empty string.

type Summarizer added in v0.4.0 

type Summarizer interface {
	Summarize(messages []session.Message) (string, error)
}

Summarizer produces a summary string from a child session's messages.

type TokenUsageCallback added in v0.5.0 

type TokenUsageCallback func(providerID, model string, input, output, total, cache int64)

TokenUsageCallback is called when a provider returns token usage data.

type ToolRegistryAdapter 

type ToolRegistryAdapter struct {
	// contains filtered or unexported fields
}

ToolRegistryAdapter adapts []*agent.Tool to knowledge.ToolRegistryProvider.

func NewToolRegistryAdapter 

func NewToolRegistryAdapter(tools []*agent.Tool) *ToolRegistryAdapter

NewToolRegistryAdapter creates a ToolRegistryAdapter from agent tools. The input slice is copied to prevent caller mutation.

func (*ToolRegistryAdapter) ListTools 

func (a *ToolRegistryAdapter) ListTools() []knowledge.ToolDescriptor

ListTools returns all available tools.

func (*ToolRegistryAdapter) SearchTools 

func (a *ToolRegistryAdapter) SearchTools(query string, limit int) []knowledge.ToolDescriptor

SearchTools returns tools whose name or description contains the query (case-insensitive).

Source Files

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