Agent Class
The Agent class is the foundation for creating AI agents in Mastra. It provides methods for generating responses, streaming interactions, and handling voice capabilities.
Usage example
src/mastra/agents/test-agent.ts
import { openai } from "@ai-sdk/openai";
import { Agent } from "@mastra/core/agent";
export const agent = new Agent({
name: "test-agent",
instructions: 'message for agent',
model: openai("gpt-4o")
});Constructor parameters
id?:
string
Optional unique identifier for the agent. Defaults to `name` if not provided.
name:
string
Unique identifier for the agent.
description?:
string
Optional description of the agent's purpose and capabilities.
instructions:
string | ({ runtimeContext: RuntimeContext }) => string | Promise<string>
Instructions that guide the agent's behavior. Can be a static string or a function that returns a string dynamically.
model:
MastraLanguageModel | ({ runtimeContext: RuntimeContext }) => MastraLanguageModel | Promise<MastraLanguageModel>
The language model used by the agent. Can be provided statically or resolved at runtime.
tools?:
ToolsInput | ({ runtimeContext: RuntimeContext }) => ToolsInput | Promise<ToolsInput>
Tools that the agent can access. Can be provided statically or resolved dynamically.
workflows?:
Record<string, Workflow> | ({ runtimeContext: RuntimeContext }) => Record<string, Workflow> | Promise<Record<string, Workflow>>
Workflows that the agent can execute. Can be static or dynamically resolved.
defaultGenerateOptions?:
AgentGenerateOptions | ({ runtimeContext: RuntimeContext }) => AgentGenerateOptions | Promise<AgentGenerateOptions>
Default options used when calling `generate()`.
defaultStreamOptions?:
AgentStreamOptions | ({ runtimeContext: RuntimeContext }) => AgentStreamOptions | Promise<AgentStreamOptions>
Default options used when calling `stream()`.
defaultVNextStreamOptions?:
AgentExecutionOptions | ({ runtimeContext: RuntimeContext }) => AgentExecutionOptions | Promise<AgentExecutionOptions>
Default options used when calling `stream()` in vNext mode.
mastra?:
Mastra
Reference to the Mastra runtime instance (injected automatically).
scorers?:
MastraScorers | ({ runtimeContext: RuntimeContext }) => MastraScorers | Promise<MastraScorers>
Scoring configuration for runtime evaluation and telemetry. Can be static or dynamically provided.
evals?:
Record<string, Metric>
Evaluation metrics for scoring agent responses.
memory?:
MastraMemory | ({ runtimeContext: RuntimeContext }) => MastraMemory | Promise<MastraMemory>
Memory module used for storing and retrieving stateful context.
voice?:
CompositeVoice
Voice settings for speech input and output.
inputProcessors?:
Processor[] | ({ runtimeContext: RuntimeContext }) => Processor[] | Promise<Processor[]>
Input processors that can modify or validate messages before they are processed by the agent. Must implement the `processInput` function.
outputProcessors?:
Processor[] | ({ runtimeContext: RuntimeContext }) => Processor[] | Promise<Processor[]>
Output processors that can modify or validate messages from the agent, before it is sent to the client. Must implement either (or both) of the `processOutputResult` and `processOutputStream` functions.
Returns
agent:
Agent<TAgentId, TTools, TMetrics>
A new Agent instance with the specified configuration.