Runtime Capacity - Crewship

The runtime capacity endpoint reports the in-memory admission snapshot for this Crewship instance: its limits, host signal, container starts currently in flight, and starts held until capacity is available. A held start is queued before a container is created; this endpoint does not pause, evict, or change an already-running container.

This is a host-wide diagnostic, not a workspace resource. The response can include holds from other workspaces because the host admission controller is shared by the daemon.

Get capacity

GET /api/v1/runtime/capacity

Authentication: An authenticated session or CLI token is required. The route is read-only and has no workspace-role or admin gate. It does not use a request body or query parameters. Response: 200 OK, application/json

{
  "enabled": true,
  "limits": {
    "MaxConcurrentStarts": 4,
    "MinStartInterval": 150000000,
    "RequiredFreeMB": 3072,
    "MaxPressurePct": 20
  },
  "in_flight_starts": 1,
  "held": [
    {
      "crew_id": "crew_123",
      "crew_slug": "alpha",
      "reason": "host_memory",
      "detail": "host has 900 MiB available, 3072 MiB needed for one more agent container",
      "since": "2026-05-19T14:00:11Z",
      "waited_ms": 42000
    }
  ],
  "held_total": 3,
  "host_signal_available": true,
  "host": {
    "AvailableMB": 900,
    "TotalMB": 16000,
    "SomeStallPct": 3.1
  }
}

limits.MinStartInterval is a Go duration encoded as nanoseconds. held is always an array, including when it is empty. held_total is the cumulative number of holds since the daemon started, while in_flight_starts and held describe the current snapshot.

Field	Type	Meaning
`enabled`	boolean	Whether admission control is wired into this instance.
`limits.MaxConcurrentStarts`	integer	Maximum container creates/starts in flight; `0` disables this leg.
`limits.MinStartInterval`	integer	Minimum spacing between admitted starts, in nanoseconds; `0` disables staggering.
`limits.RequiredFreeMB`	integer	Host memory that must remain available for a start; `0` disables this leg.
`limits.MaxPressurePct`	number	PSI `some avg10` ceiling; `0` disables this veto.
`in_flight_starts`	integer	Starts currently admitted but not finished.
`held`	array	Current holds, with reason, detail, start time, and wait duration.
`held_total`	integer	Holds observed since daemon startup.
`host_signal_available`	boolean	Whether Linux host memory signals are available.
`host_signal_error`	string?	Why the host signal is unavailable or admission control is not configured; omitted when empty.
`host.AvailableMB`	integer	Current `MemAvailable` in MiB when the signal is available.
`host.TotalMB`	integer	Current `MemTotal` in MiB.
`host.SomeStallPct`	number	PSI memory `some avg10` percentage, or `-1` when PSI is unavailable.

The stable hold reasons are host_memory, host_pressure, concurrency, and pacing. On macOS, or where the Linux /proc signals are unavailable, host_signal_available is false; the memory and pressure checks are inactive, but concurrency and staggering can still apply. Errors:

Status	Condition
`401 Unauthorized`	Missing or invalid authentication.

When admission control is not configured, the endpoint still returns 200: enabled is false, held is an empty array, and host_signal_error explains the state. The handler is read-only and does not return a documented application-level 4xx or 5xx for a capacity snapshot.

crewship capacity — human-readable and formatted output.
crewship now — includes held starts on the live board.
crewship instance — change the instance settings used by the next admission decision.

​Get capacity

​Related CLI

Get capacity

Related CLI