Create a session — starts provisioning by default; optionally defer until the first turn [write]

An agent id, or "@handle" for an agent from the catalog (GET /catalog/agents). A handle that names a platform engine uses the workspace's agent for that engine, created on first use.

Model for this session (a current model for the agent's harness). Omitted = the agent's model

Reasoning effort for this session; omitted or null inherits the agent's setting normalized for the target model. Explicit values must fit both harness and target model - agoragentic_acp: not supported; amp_acp: not supported; auggie: not supported; autohand: not supported; cline: not supported; codebuddy_code: not supported; cortex_code: not supported; corust_agent: not supported; crow_cli: not supported; cursor: not supported; deepagents: not supported; devin: not supported; dimcode: not supported; dirac: not supported; factory_droid: not supported; fast_agent: not supported; gemini: not supported; github_copilot_cli: not supported; glm_acp_agent: not supported; antigravity_acp: not supported; goose: not supported; grok_build: not supported; harn: not supported; junie: not supported; kilo: not supported; kimchi: not supported; minimax_code: not supported; minion_code: not supported; mistral_vibe: not supported; nova: not supported; poolside: not supported; qoder: not supported; qwen_code: not supported; sigit: not supported; stakpak: not supported; vtcode: not supported; code_assistant: not supported; docker_cagent: not supported; kiro: not supported; muse_code: not supported; openhands: not supported; hermes: none/minimal/low/medium/high/xhigh/max/ultra; claude_code: low/medium/high/xhigh/max; codex: none/minimal/low/medium/high/xhigh/max; openclaw: not supported; jev: not supported; pi: off/minimal/low/medium/high/xhigh/max; dsh: not supported; kimi_code: not supported; opencode: none/minimal/low/medium/high/xhigh/max; workspace_acp: not supported; models: claude-fable-5-1: low/medium/high/xhigh/max; claude-fable-5: low/medium/high/xhigh/max; claude-opus-5-5: low/medium/high/xhigh/max; claude-opus-5: low/medium/high/xhigh/max; claude-opus-4-8: low/medium/high/xhigh/max; claude-sonnet-5-5: low/medium/high/xhigh/max; claude-sonnet-5: low/medium/high/xhigh/max; claude-sonnet-4-6: low/medium/high/max; claude-haiku-5-5: low/medium/high/xhigh/max; claude-haiku-4-5: not supported; gpt-6.1-sol: low/medium/high/xhigh/max; gpt-6-astra: low/medium/high/xhigh/max; gpt-6-sol: none/low/medium/high/xhigh/max; gpt-6-luna: none/low/medium/high/xhigh/max; gpt-5.6-sol: none/low/medium/high/xhigh/max; gpt-5.6-terra: none/low/medium/high/xhigh/max; gpt-5.6-luna: none/low/medium/high/xhigh/max; gpt-5.5: none/low/medium/high/xhigh; gpt-4.1: not supported; deepseek-v4-pro: low/high/max; deepseek-flash: low/high/max; kimi-k3.1-pro: low/high/max; kimi-k3: low/high/max; kimi-k2.7-code: not supported; minimax-m3: not supported; muse-spark-1.1: minimal/low/medium/high/xhigh; muse-spark-1.2: minimal/low/medium/high/xhigh; muse-spark-1.3: minimal/low/medium/high/xhigh/max; minimax-m3.1-flash: low/medium/high/xhigh/max; gemini-4-argon: low/medium/high; gemini-3.5-flash-lite: low/medium/high; gemini-3.8-flash: low/medium/high; gemini-3.5-flash: low/medium/high; glm-5.3: low/high/max; glm-5.3-flash: low/high/max; grok-4.6: low/medium/high; grok-4.7: low/medium/high/xhigh

Seconds this session's machine stays awake after a turn ends before it is paused (60-86400; omitted = the platform default of 60). A paused machine wakes on the next message; apps the agent serves on exposed ports are unreachable while it is paused, so set this to how long people keep using them after the agent finishes

eager (default) boots the sandbox as soon as the row exists; deferred leaves the session idle with no pod until its first turn, so a session waiting on a gate or a schedule costs nothing while it waits. Ignored when initial_events start the first turn

After every subscription account is exhausted, continue on the same model using the paid platform API; wallet and session budget still apply

Who pays for model calls: platform wallet or the user's connected subscription. Omitted = auto-apply (a connected subscription with "use for new agents" powers eligible compositions)

Which balance pays for the session, in a team workspace that has a wallet of its own: "workspace" (the default there) or "personal", the caller's own. Decided once, here, and shown as payer on the session and its task. "workspace" where the workspace has no wallet is refused with 409 workspace_wallet_unavailable.

Whether the session also starts with its workspace's defaults: the default environment when none is named, the default vault when it holds a secret, the team memory stores that attach by default, and the always-available files and skills. "none" attaches only what this request names. Omitted means "workspace".