---
title: Build workouts
description: Resolve exercises, build a draft session, read it back, and publish separately.
---

`buildSession()` creates one session inside a program, saves its blocks and exercises, and can
optionally publish it. The safer workflow is draft first, inspect second, publish last.

1. **Resolve every exercise**

    Use the [exercise library](/developers/sdk/exercises) to turn names into TrainHeroic ids.

2. **Build a draft**

    Set `publish: false` and keep the returned `pwId`.

3. **Read it back**

    Verify the encoded session before it becomes athlete-visible.

4. **Publish deliberately**

    Call `publishSession()` only after the draft matches the intended programming.

```ts
import { buildSession } from "@trainheroic-unofficial/js";

const { match } = await library.resolve("Back Squat");
if (!match) throw new Error("Choose one exercise before building");

const { pwId, workoutId } = await buildSession(client, {
  programId: 12345,
  date: [2026, 8, 17], // [year, month, day], with a 1-based month
  instruction: "Warm up first.",
  blocks: [
    {
      title: "Strength",
      exercises: [{ id: match.id, sets: 5, reps: 5, weight: 225, rpe: 8 }],
    },
  ],
  publish: false,
});
```

`reps` and `weight` accept one scalar for every set or a per-set array such as
`reps: [5, 5, 3]`. Loads use the unit configured on the exercise in TrainHeroic.

## Session handles

- `pwId` identifies the session's placement in the program. Read, publish, unpublish, copy,
  and remove operations use it.
- `workoutId` identifies the underlying workout record.

:::warning
Publishing makes the session visible to athletes. The MCP and CLI surfaces require explicit
confirmation for that step; direct SDK callers own their own confirmation policy.
:::