Request Syntax URI Request Parameters Request Body Response Syntax Response Elements Errors See Also

CreateHarness

Operation to create a Harness.

Request Syntax


POST /harnesses HTTP/1.1
Content-type: application/json

{
   "allowedTools": [ "string" ],
   "authorizerConfiguration": { ... },
   "clientToken": "string",
   "environment": { ... },
   "environmentArtifact": { ... },
   "environmentVariables": { 
      "string" : "string" 
   },
   "executionRoleArn": "string",
   "harnessName": "string",
   "maxIterations": number,
   "maxTokens": number,
   "memory": { ... },
   "model": { ... },
   "skills": [ 
      { ... }
   ],
   "systemPrompt": [ 
      { ... }
   ],
   "tags": { 
      "string" : "string" 
   },
   "timeoutSeconds": number,
   "tools": [ 
      { 
         "config": { ... },
         "name": "string",
         "type": "string"
      }
   ],
   "truncation": { 
      "config": { ... },
      "strategy": "string"
   }
}

URI Request Parameters

The request does not use any URI parameters.

Request Body

The request accepts the following data in JSON format.

allowedTools

The tools that the agent is allowed to use. Supports glob patterns such as * for all tools, @builtin for all built-in tools, or @serverName/toolName for specific MCP server tools.

Type: Array of strings

Length Constraints: Minimum length of 1. Maximum length of 64.

Pattern: (\*|@?[^/]+(/[^/]+)?)

Required: No

authorizerConfiguration

Represents inbound authorization configuration options used to authenticate incoming requests.

Type: AuthorizerConfiguration object

Note: This object is a Union. Only one member of this object can be specified or returned.

Required: No

clientToken

A unique, case-sensitive identifier to ensure idempotency of the request.

Type: String

Length Constraints: Minimum length of 33. Maximum length of 256.

Pattern: [a-zA-Z0-9](-*[a-zA-Z0-9]){0,256}

Required: No

environment

The compute environment configuration for the harness, including network and lifecycle settings.

Type: HarnessEnvironmentProviderRequest object

Note: This object is a Union. Only one member of this object can be specified or returned.

Required: No

environmentArtifact

The environment artifact for the harness, such as a custom container image containing additional dependencies.

Type: HarnessEnvironmentArtifact object

Note: This object is a Union. Only one member of this object can be specified or returned.

Required: No

environmentVariables

Environment variables to set in the harness runtime environment.

Type: String to string map

Map Entries: Minimum number of 0 items. Maximum number of 50 items.

Key Length Constraints: Minimum length of 1. Maximum length of 100.

Value Length Constraints: Minimum length of 0. Maximum length of 5000.

Required: No

executionRoleArn

The ARN of the IAM role that the harness assumes when running. This role must have permissions for the services the agent needs to access, such as Amazon Bedrock for model invocation.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 2048.

Pattern: arn:aws(-[^:]+)?:iam::([0-9]{12})?:role/.+

Required: Yes

harnessName

The name of the harness. Must start with a letter and contain only alphanumeric characters and underscores.

Type: String

Pattern: [a-zA-Z][a-zA-Z0-9_]{0,39}

Required: Yes

maxIterations

The maximum number of iterations the agent loop can execute per invocation.

Type: Integer

Required: No

maxTokens

The maximum total number of output tokens the agent can generate across all model calls within a single invocation.

Type: Integer

Required: No

memory

The AgentCore Memory configuration for persisting conversation context across sessions.

Type: HarnessMemoryConfiguration object

Note: This object is a Union. Only one member of this object can be specified or returned.

Required: No

model

The model configuration for the harness. Supports Amazon Bedrock, OpenAI, and Google Gemini model providers.

Type: HarnessModelConfiguration object

Note: This object is a Union. Only one member of this object can be specified or returned.

Required: No

skills

The skills available to the agent. Skills are bundles of files that the agent can pull into its context on demand.

Type: Array of HarnessSkill objects

Required: No

systemPrompt

The system prompt that defines the agent's behavior and instructions.

Type: Array of HarnessSystemContentBlock objects

Required: No

tags

Tags to apply to the harness resource.

Type: String to string map

Map Entries: Minimum number of 0 items. Maximum number of 50 items.

Key Length Constraints: Minimum length of 1. Maximum length of 128.

Key Pattern: [a-zA-Z0-9\s._:/=+@-]*

Value Length Constraints: Minimum length of 0. Maximum length of 256.

Value Pattern: [a-zA-Z0-9\s._:/=+@-]*

Required: No

timeoutSeconds

The maximum duration in seconds for the agent loop execution per invocation.

Type: Integer

Required: No

tools

The tools available to the agent, such as remote MCP servers, AgentCore Gateway, AgentCore Browser, Code Interpreter, or inline functions.

Type: Array of HarnessTool objects

Required: No

truncation

The truncation configuration for managing conversation context when it exceeds model limits.

Type: HarnessTruncationConfiguration object

Required: No

Response Syntax


HTTP/1.1 201
Content-type: application/json

{
   "harness": { 
      "allowedTools": [ "string" ],
      "arn": "string",
      "authorizerConfiguration": { ... },
      "createdAt": "string",
      "environment": { ... },
      "environmentArtifact": { ... },
      "environmentVariables": { 
         "string" : "string" 
      },
      "executionRoleArn": "string",
      "failureReason": "string",
      "harnessId": "string",
      "harnessName": "string",
      "maxIterations": number,
      "maxTokens": number,
      "memory": { ... },
      "model": { ... },
      "skills": [ 
         { ... }
      ],
      "status": "string",
      "systemPrompt": [ 
         { ... }
      ],
      "timeoutSeconds": number,
      "tools": [ 
         { 
            "config": { ... },
            "name": "string",
            "type": "string"
         }
      ],
      "truncation": { 
         "config": { ... },
         "strategy": "string"
      },
      "updatedAt": "string"
   }
}

Response Elements

If the action is successful, the service sends back an HTTP 201 response.

The following data is returned in JSON format by the service.

harness

The harness that was created.

Type: Harness object

Errors

For information about the errors that are common to all actions, see Common Error Types.

AccessDeniedException

This exception is thrown when a request is denied per access permissions

HTTP Status Code: 403

ConflictException

This exception is thrown when there is a conflict performing an operation

HTTP Status Code: 409

InternalServerException

This exception is thrown if there was an unexpected error during processing of request

HTTP Status Code: 500

ServiceQuotaExceededException

This exception is thrown when a request is made beyond the service quota

HTTP Status Code: 402

ThrottlingException

This exception is thrown when the number of requests exceeds the limit

HTTP Status Code: 429

ValidationException

The input fails to satisfy the constraints specified by the service.

HTTP Status Code: 400