Swap an exercise

Replaces a slot’s exercise from the given week on (default all unlogged weeks). Logged sets keep the exercise they were done with.

PATCH/api/training/slots/{id}

Authorization

__Secure-better-auth.session_tokenAPI key · cookierequired

Better Auth session. Signing in (Google or email magic link) sets an HttpOnly session cookie that scopes every request to that account. The web app and CLI use this; agents use the OAuth 2.1 flow of the MCP server.

AuthorizationBearer token · headerrequired

Personal API key sent as Authorization: Bearer skcal_…. Create and scope keys in the app under your profile → API keys. Keys default to full access; a scoped key is limited to its granted resource:action permissions and cannot manage other keys.

Path parameters

idstringrequired

Identifier of the mesocycle, set, slot, or custom exercise the path names.

Request body

requiredapplication/json

The replacement exercise, by id or name.

exerciseIdstring

Id of the replacement exercise from the library.

exerciseNamestring

Exercise name, matched against the library within the slot's muscle.

fromWeekinteger

First week to change (default 1, every unlogged set).

Responses

200

The exercise was swapped.

object

400

The request body or parameters failed validation.

errorstringrequired

Human-readable failure reason.

detailstring

Optional extra context, present on upstream failures.

404

No matching resource owned by the caller.

errorstringrequired

Human-readable failure reason.

detailstring

Optional extra context, present on upstream failures.

Try it

Server

Base URLCustom base URLOverrides the selected server when set.

Authorization

API keyRemember on this deviceInclude my values in samples

Parameters

idpath*Identifier of the mesocycle, set, slot, or custom exercise the path names.

Bodyapplication/json

exerciseIdstringId of the replacement exercise from the library.exerciseNamestringExercise name, matched against the library within the slot's muscle.fromWeekintegerFirst week to change (default 1, every unlogged set).

Request

curl -X PATCH 'https://app.skcal.fit/api/training/slots/9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d' \
  -H 'Cookie: __Secure-better-auth.session_token=YOUR_API_KEY' \
  -H 'Accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
  "exerciseId": "incline_dumbbell_press",
  "exerciseName": "incline dumbbell press",
  "fromWeek": 3
}'

const response = await fetch("https://app.skcal.fit/api/training/slots/9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d", {
  method: "PATCH",
  headers: {
    "Cookie": "__Secure-better-auth.session_token=YOUR_API_KEY",
    "Accept": "application/json",
    "Content-Type": "application/json"
  },
  body: "{\n  \"exerciseId\": \"incline_dumbbell_press\",\n  \"exerciseName\": \"incline dumbbell press\",\n  \"fromWeek\": 3\n}"
});

import requests

response = requests.patch(
    "https://app.skcal.fit/api/training/slots/9a8b7c6d-5e4f-4a3b-8c2d-1e0f9a8b7c6d",
    headers={
        "Cookie": "__Secure-better-auth.session_token=YOUR_API_KEY",
        "Accept": "application/json",
        "Content-Type": "application/json"
    },
    data="{\n  \"exerciseId\": \"incline_dumbbell_press\",\n  \"exerciseName\": \"incline dumbbell press\",\n  \"fromWeek\": 3\n}",
)

Response

{
  "ok": true,
  "week": 2,
  "day": 1,
  "exerciseName": "Barbell Bench Press",
  "muscle": "chest"
}

{
  "error": "weightKg must be 9-320 kg",
  "detail": "upstream model returned 500"
}

{
  "error": "weightKg must be 9-320 kg",
  "detail": "upstream model returned 500"
}