Readonly[ReadonlyincludeReadonlyincludeReadonlynameReadonlyoutputCallback executed after an agent's primary logic has completed.
This callback can be used to inspect, log, or modify the agent's final result before it is returned.
An optional Content object. If a value is returned, it will
replace the agent's original result. Returning undefined uses the
original, unmodified result.
Callback executed after context compaction.
This callback provides an opportunity to inspect the context after it has been compacted.
The context for the entire invocation.
The trigger for the context compaction.
Callback executed after a response is received from the model.
This is the ideal place to log model responses, collect metrics on token
usage, or perform post-processing on the raw LlmResponse.
An optional value. A non-undefined return may be used by the
framework to modify or replace the response. Returning undefined
allows the original response to be used.
Callback executed after a workflow node has run.
Not called for a node whose body was skipped by beforeNodeCallback, and
not called when the node throws.
The node that has just run.
The node's execution context.
The output the node produced.
An optional value replacing the node's output. Returning
undefined keeps the original.
Callback executed after an ADK runner run has completed.
This is the final callback in the ADK lifecycle, suitable for cleanup, final logging, or reporting tasks.
undefined
Callback executed after a tool has been called.
This callback allows for inspecting, logging, or modifying the result returned by a tool.
An optional dictionary. If a dictionary is returned, it will
replace the original result from the tool. This allows for
post-processing or altering tool outputs. Returning undefined uses
the original, unmodified result.
Callback executed before an agent's primary logic is invoked.
This callback can be used for logging, setup, or to short-circuit the agent's execution by returning a value.
An optional Content object. If a value is returned, it will
bypass the agent's callbacks and its execution, and return this value
directly. Returning undefined allows the agent to proceed normally.
Callback executed before context compaction.
This callback provides an opportunity to inspect or modify the context before it is compacted.
The context for the entire invocation.
The trigger for the context compaction.
Callback executed before a request is sent to the model.
This provides an opportunity to inspect, log, or modify the LlmRequest
object. It can also be used to implement caching by returning a cached
LlmResponse, which would skip the actual model call.
An optional value. The interpretation of a non-undefined
trigger an early exit and returns the response immediately. Returning
undefined allows the LLM request to proceed normally.
Callback executed before a workflow node runs.
The input the node is about to receive.
The node that is about to run.
The node's execution context.
An optional value. If anything other than undefined is returned,
the node's body is skipped and the returned value becomes its output,
which is how a plugin implements a node-level cache or a stub.
Returning undefined lets the node run normally.
Callback executed before the ADK runner runs.
This is the first callback to be called in the lifecycle, ideal for global setup or initialization tasks.
An optional Event to be returned to the ADK. Returning a value
to halt execution of the runner and ends the runner with that event.
Return undefined to proceed normally.
Callback executed before a tool is called.
This callback is useful for logging tool usage, input validation, or modifying the arguments before they are passed to the tool.
An optional dictionary. If a dictionary is returned, it will stop
the tool execution and return this response immediately. Returning
undefined uses the original, unmodified arguments.
Callback executed before a tool is selected.
This callback provides an opportunity to inspect, log, or modify the available tools before they are selected.
An optional value. A non-undefined return may be used by the
framework to modify or replace the available tools. Returning
undefined allows the original tools to be used.
Exposes active invocation states for testing and inspection.
Callback executed after an event is yielded from runner.
This is the ideal place to make modification to the event before the event is handled by the underlying agent app.
An optional value. A non-undefined return may be used by the
framework to modify or replace the response. Copy the incoming
event when constructing a replacement to preserve fields that are not
being modified, such as event actions. Returning undefined allows the
original response to be used.
Callback executed when a model call encounters an error.
This callback provides an opportunity to handle model errors gracefully, potentially providing alternative responses or recovery mechanisms.
An optional LlmResponse. If an LlmResponse is returned, it will be
used instead of propagating the error. Returning undefined allows
the original error to be raised.
Callback executed when a tool call encounters an error. tool: BaseTool; toolArgs: Record<string, unknown>; toolContext: Context; result: Record<string, unknown>; }): Promise<Record<string, unknown> | undefined> { return; }
/** Callback executed when a tool call encounters an error.
This callback provides an opportunity to handle tool errors gracefully, potentially providing alternative responses or recovery mechanisms.
An optional dictionary. If a dictionary is returned, it will be
used as the tool response instead of propagating the error. Returning
undefined allows the original error to be raised.
Callback executed when a user message is received before an invocation starts.
This callback helps logging and modifying the user message before the runner starts the invocation.
An optional Content to be returned to the ADK. Returning a
value to replace the user message. Returning undefined to proceed
normally.
Safely serializes an arbitrary value to a YAML/JSON-compatible format with credential, sensitive key, and private key redaction.
Serializes a Gemini Content object to a dictionary for YAML output.
A plugin that captures complete debug information to a YAML file.
This plugin records detailed interaction data including:
Each invocation is appended to the output file as a separate YAML document (separated by
---). Credentials, sensitive keys,temp:-scoped state keys, and armored private key blocks are automatically redacted to[REDACTED].