Claude Platform Docs

Create Agent

$ ant beta:agents create
POST/v1/agents

Create Agent

Parameters
--model: BetaManagedAgentsModelConfigParams { id, effort, inference_geo, speed }

Body param: Model identifier. Accepts the model string, e.g. claude-opus-5, or a model_config object for additional configuration control

--name: string

Body param: Human-readable name for the agent.

minLength1
maxLength256
--description: optional string

Body param: Description of what the agent does.

maxLength2048
--mcp-server: optional array of BetaManagedAgentsURLMCPServerParams { name, type, url }

Body param: MCP servers this agent connects to. Maximum 20. Names must be unique within the array. Every server must be referenced by an mcp_toolset in tools; unreferenced servers are rejected. See the MCP connector guide.

--metadata: optional map[string]

Body param: Arbitrary key-value metadata. Maximum 16 pairs, keys up to 64 chars, values up to 512 chars.

--multiagent: optional object{ agents, type }

Body param: A coordinator topology: the session's primary thread orchestrates work by spawning session threads, each running an agent drawn from the agents roster.

--skill: optional array of BetaManagedAgentsSkillParams

Body param: Skills available to the agent.

--system: optional string

Body param: System prompt for the agent.

maxLength100000
--tool: optional array of BetaManagedAgentsAgentToolset20260401Params { type, configs, default_config } or BetaManagedAgentsMCPToolsetParams { mcp_server_name, type, configs, default_config } or BetaManagedAgentsCustomToolParams { description, input_schema, name, type }

Body param: Tool configurations available to the agent. Maximum of 128 tools across all toolsets allowed.

--beta: optional array of AnthropicBeta

Header param: Optional header to specify the beta version(s) you want to use.

Returns
beta_managed_agents_agent: object{ id, archived_at, created_at, 12 more }

A Managed Agents agent.

id: string
archived_at: string

A timestamp in RFC 3339 format

formatdate-time
created_at: string

A timestamp in RFC 3339 format

formatdate-time
description: string
mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition { name, type, url }
name: string
type: "url"
url: string
metadata: map[string]
model: object{ id, effort, inference_geo, speed }

Model identifier and configuration.

id: "claude-sonnet-5" or "claude-fable-5" or "claude-opus-5" or 10 more or string

The model that will power your agent.

See models for additional details and options.

One of the following:
"claude-sonnet-5"

High-performance model for coding and agents

"claude-fable-5"

Next generation of intelligence for the hardest knowledge work and coding problems

"claude-opus-5"

Powerful intelligence for long-running agents and coding

"claude-opus-4-8"

Powerful intelligence for long-running agents and coding

"claude-opus-4-7"

Powerful intelligence for long-running agents and coding

"claude-opus-4-6"

Powerful intelligence for long-running agents and coding

"claude-sonnet-4-6"

Best combination of speed and intelligence

"claude-haiku-4-5"

Fastest model with near-frontier intelligence

"claude-haiku-4-5-20251001"

Fastest model with near-frontier intelligence

"claude-opus-4-5"

Powerful intelligence for long-running agents and coding

"claude-opus-4-5-20251101"

Powerful intelligence for long-running agents and coding

"claude-sonnet-4-5"

High-performance model for agents and coding

"claude-sonnet-4-5-20250929"

High-performance model for agents and coding

effort: optional BetaManagedAgentsEffortLow { type } or BetaManagedAgentsEffortMedium { type } or BetaManagedAgentsEffortHigh { type } or 2 more

How hard Claude works on each turn. Sets output_config.effort on every Messages call the session makes.

One of the following:
beta_managed_agents_effort_low: object{ type }

Low effort. Favors latency over reasoning depth.

type: "low"
beta_managed_agents_effort_medium: object{ type }

Medium effort. Balances latency and reasoning depth.

type: "medium"
beta_managed_agents_effort_high: object{ type }

High effort. Favors reasoning depth.

type: "high"
beta_managed_agents_effort_xhigh: object{ type }

Extra-high effort. Not all models accept this level.

type: "xhigh"
beta_managed_agents_effort_max: object{ type }

Maximum effort. Favors reasoning depth over latency.

type: "max"
inference_geo: optional string

Geographic region for model inference. When unset, requests fall through to the workspace's default_inference_geo.

speed: optional "standard" or "fast"

Inference speed mode. fast provides significantly faster output token generation at premium pricing. Not all models support fast; invalid combinations are rejected at create time.

One of the following:
"standard"
"fast"
multiagent: object{ agents, type }

Resolved coordinator topology with a concrete agent roster.

agents: array of BetaManagedAgentsAgentReference { id, type, version } or BetaManagedAgentsAdvisor { model, type }

Agents the coordinator may spawn as session threads, each resolved to a specific version.

One of the following:
beta_managed_agents_agent_reference: object{ id, type, version }

A resolved agent reference with a concrete version.

id: string
type: "agent"
version: number
formatint32
beta_managed_agents_advisor: object{ model, type }

Platform advisor roster entry: a model the session's primary thread may consult mid-turn.

model: string

The advisor model id.

type: "advisor"
type: "coordinator"
name: string
skills: array of BetaManagedAgentsAnthropicSkill { skill_id, type, version } or BetaManagedAgentsCustomSkill { skill_id, type, version }
One of the following:
beta_managed_agents_anthropic_skill: object{ skill_id, type, version }

A resolved Anthropic-managed skill.

skill_id: string
type: "anthropic"
version: string
beta_managed_agents_custom_skill: object{ skill_id, type, version }

A resolved user-created custom skill.

skill_id: string
type: "custom"
version: string
system: string
tools: array of BetaManagedAgentsAgentToolset20260401 { configs, default_config, type } or BetaManagedAgentsMCPToolset { configs, default_config, mcp_server_name, type } or BetaManagedAgentsCustomTool { description, input_schema, name, type }
One of the following:
beta_managed_agents_agent_toolset20260401: object{ configs, default_config, type }
beta_managed_agents_mcp_toolset: object{ configs, default_config, mcp_server_name, type }
beta_managed_agents_custom_tool: object{ description, input_schema, name, type }

A custom tool as returned in API responses.

description: string
input_schema: object{ type, properties, required }

JSON Schema for custom tool input parameters.

type: "object"
properties: optional map[unknown]
required: optional array of string
name: string
type: "custom"
type: "agent"
updated_at: string

A timestamp in RFC 3339 format

formatdate-time
version: number

The agent's current version. Starts at 1 and increments when the agent is modified.

formatint32

Create Agent

ant beta:agents create \
  --api-key my-anthropic-api-key \
  --model '{id: claude-opus-5}' \
  --name 'My First Agent'
{
  "id": "agent_011CZkYpogX7uDKUyvBTophP",
  "archived_at": null,
  "created_at": "2026-03-15T10:00:00Z",
  "description": "A general-purpose starter agent.",
  "mcp_servers": [
    {
      "name": "example-mcp",
      "type": "url",
      "url": "https://example-server.modelcontextprotocol.io/sse"
    }
  ],
  "metadata": {
    "foo": "bar"
  },
  "model": {
    "id": "claude-opus-5",
    "effort": {
      "type": "low"
    },
    "inference_geo": "inference_geo",
    "speed": "standard"
  },
  "multiagent": {
    "agents": [
      {
        "id": "agent_011CZkYqphY8vELVzwCUpqiQ",
        "type": "agent",
        "version": 1
      }
    ],
    "type": "coordinator"
  },
  "name": "My First Agent",
  "skills": [
    {
      "skill_id": "xlsx",
      "type": "anthropic",
      "version": "1"
    },
    {
      "skill_id": "skill_011CZkZFNu9hAbo3jZPRgTlx",
      "type": "custom",
      "version": "2"
    }
  ],
  "system": "You are a general-purpose agent that can research, write code, run commands, and use connected tools to complete the user's task end to end.",
  "tools": [
    {
      "configs": [
        {
          "enabled": true,
          "name": "bash",
          "permission_policy": {
            "type": "always_allow"
          },
          "type": "bash"
        }
      ],
      "default_config": {
        "enabled": true,
        "permission_policy": {
          "type": "always_ask"
        }
      },
      "type": "agent_toolset_20260401"
    }
  ],
  "type": "agent",
  "updated_at": "2026-03-15T10:00:00Z",
  "version": 1
}
Returns Examples
{
  "id": "agent_011CZkYpogX7uDKUyvBTophP",
  "archived_at": null,
  "created_at": "2026-03-15T10:00:00Z",
  "description": "A general-purpose starter agent.",
  "mcp_servers": [
    {
      "name": "example-mcp",
      "type": "url",
      "url": "https://example-server.modelcontextprotocol.io/sse"
    }
  ],
  "metadata": {
    "foo": "bar"
  },
  "model": {
    "id": "claude-opus-5",
    "effort": {
      "type": "low"
    },
    "inference_geo": "inference_geo",
    "speed": "standard"
  },
  "multiagent": {
    "agents": [
      {
        "id": "agent_011CZkYqphY8vELVzwCUpqiQ",
        "type": "agent",
        "version": 1
      }
    ],
    "type": "coordinator"
  },
  "name": "My First Agent",
  "skills": [
    {
      "skill_id": "xlsx",
      "type": "anthropic",
      "version": "1"
    },
    {
      "skill_id": "skill_011CZkZFNu9hAbo3jZPRgTlx",
      "type": "custom",
      "version": "2"
    }
  ],
  "system": "You are a general-purpose agent that can research, write code, run commands, and use connected tools to complete the user's task end to end.",
  "tools": [
    {
      "configs": [
        {
          "enabled": true,
          "name": "bash",
          "permission_policy": {
            "type": "always_allow"
          },
          "type": "bash"
        }
      ],
      "default_config": {
        "enabled": true,
        "permission_policy": {
          "type": "always_ask"
        }
      },
      "type": "agent_toolset_20260401"
    }
  ],
  "type": "agent",
  "updated_at": "2026-03-15T10:00:00Z",
  "version": 1
}