API documentation | API docs for agents | OpenAPI 3.1

agent-sessions

ark.start_agent_session

Creates an MCP or hosted-agent session record for run tracking, budgets, approval linkage, and audit attribution.

Availability: Expanded preview
Scopes: agents:write
ARK permissions: None
Team visibility: Not entity-scoped
Idempotency-Key: Required for this write
Approval: No MCP approval on REST API-token calls
Rate limit: API credential and organization budgets

Parameters

Idempotency-Keyheaderstringrequired: Required for external write operations. Reuse the same key only for exact retries of the same request body.; min length: 1; max length: 200

Request body

titlestring

min length: 1; max length: 160

goalstring

min length: 1; max length: 2000

clientNamestring

min length: 1; max length: 160

clientSessionIdstring

min length: 1; max length: 200

maxToolCallsinteger

min: 1; max: 10000

expiresInMinutesinteger

default: 480; min: 5; max: 43200

metadataobject

Example request

Shell

curl -X POST 'https://arktms.com/api/v1/agent-sessions' \
  -H "Authorization: Bearer $ARK_API_TOKEN" \
  -H "Idempotency-Key: <unique-key>" \
  -H "Content-Type: application/json" \
  -d '{}'

Success response

Started agent session

objectstringrequired

okbooleanrequired

api_versionstringrequired

request_idstringrequired

dataobjectrequired

data.sessionobjectrequired

Errors

HTTP 400: Invalid request
HTTP 401: Authentication required
HTTP 403: Permission, scope, team, or entitlement denied
HTTP 409: Idempotency conflict or in-progress retry