Quickstart

1. Inspect Supported Movements

Call GET /v1/movements before building a compute payload.

curl https://api.workcapacity.io/v1/movements

This tells you:

• which movements exist
• which inputs are required
• which alternative inputs are allowed
• which overrides are supported
• which assumptions the compute model uses

Sample fragment:

{
  "air_squat": {
    "required_inputs": [],
    "supported_overrides": ["height_coefficient"]
  },
  "thruster": {
    "required_inputs": [
      {
        "name": "external_load",
        "allowed_units": ["kg", "lb"]
      }
    ]
  },
  "row": {
    "alternative_inputs": [
      {
        "description": "Provide either rowing distance or displayed calories.",
        "options": [
          { "name": "travel_distance", "allowed_units": ["m", "ft"] },
          { "name": "calories", "allowed_units": ["kcal"] }
        ]
      }
    ]
  }
}

2. Build A Minimal Split-Aware Request

This example uses distinct movement chunks as separate splits. Top-level duration_seconds is session elapsed time, while each split duration_seconds is active time only.

{
  "athlete_uuid": "11111111-1111-1111-1111-111111111111",
  "evaluation_context": "completed",
  "performed_date": "2026-03-20",
  "duration_seconds": 133,
  "user": {
    "height": { "value": 70, "unit": "in" },
    "body_mass": { "value": 180, "unit": "lb" },
    "age_years": 35,
    "sex": "male"
  },
  "splits": [
    {
      "label": "21 thrusters",
      "duration_seconds": 33,
      "work": {
        "movements": [
          {
            "movement": "thruster",
            "reps": 21,
            "inputs": {
              "external_load": { "value": 95, "unit": "lb" }
            },
            "spec_overrides": {}
          }
        ]
      }
    },
    {
      "label": "21 pull-ups",
      "duration_seconds": 27,
      "work": {
        "movements": [
          {
            "movement": "pull_up",
            "reps": 21,
            "spec_overrides": {}
          }
        ]
      }
    },
    {
      "label": "15 thrusters",
      "duration_seconds": 24,
      "work": {
        "movements": [
          {
            "movement": "thruster",
            "reps": 15,
            "inputs": {
              "external_load": { "value": 95, "unit": "lb" }
            },
            "spec_overrides": {}
          }
        ]
      }
    },
    {
      "label": "15 pull-ups",
      "duration_seconds": 20,
      "work": {
        "movements": [
          {
            "movement": "pull_up",
            "reps": 15,
            "spec_overrides": {}
          }
        ]
      }
    }
  ]
}

3. Call The Paid Endpoint

First request:

curl https://api.workcapacity.io/v1/compute-power \
  -H 'Content-Type: application/json' \
  -d @payload.json

In production, POST /v1/compute-power is a paid route. The first response may be:

HTTP/1.1 402 Payment Required
PAYMENT-REQUIRED: <x402 payment requirement payload>
WWW-Authenticate: L402 macaroon="<token>", invoice="<lightning invoice>"

4. Pay And Retry

If your client supports x402, send the proof in:

PAYMENT-SIGNATURE: <x402 proof>

Successful x402 responses also include:

PAYMENT-RESPONSE: <x402 settlement payload>

If your client supports L402, pay the Lightning invoice from WWW-Authenticate and retry with:

Authorization: L402 <token>:<preimage>

For the current route price and any revision-route pricing, read GET /v1/payment-requirements or inspect the machine-readable metadata in https://api.workcapacity.io/openapi.json. x402 uses the published USD display price directly. L402 invoices are sats derived from that same USD price using a cached live BTC/USD quote.

5. Read The Response

Small response excerpt:

{
  "results": {
    "session": {
      "duration_seconds": 133,
      "active_duration_seconds": 104,
      "unattributed_duration_seconds": 29,
      "total_work": { "value": 33873.0, "unit": "ft·lbf" },
      "average_power_elapsed": { "value": 15281.05, "unit": "ft·lbf/min" },
      "average_power_active": { "value": 19542.12, "unit": "ft·lbf/min" }
    },
    "summary": {
      "peak_split_power": { "value": 22295.0, "unit": "ft·lbf/min" },
      "min_split_power": { "value": 16065.0, "unit": "ft·lbf/min" },
      "power_dropoff_percent": 27.94,
      "consistency_score": 85.03
    }
  },
  "notes": [
    "Session average power uses full session elapsed time (top-level duration_seconds).",
    "Split average power uses split duration_seconds only and excludes rest_seconds_after.",
    "Top-level duration_seconds exceeds accounted split time by 29 seconds; that remainder is included in session metrics but not assigned to any split."
  ]
}

Interpretation:

• results.session tells you how the full session behaved.
• results.splits[] tells you how each work segment behaved in active time.
• results.summary tells you whether output stayed steady or dropped off.
• notes explains denominator semantics and unattributed duration.