---
title: Steering and checkpoints
description: How to redirect a running session, answer its questions, pause, resume, cancel, extend the budget, change permissions, ask about its evidence, and rewind to an exact earlier version.
---

A session isn't fire-and-forget. While it runs — and after it finishes — you can
redirect it at any point, from the portal or your phone.

## Everything you can do to a session

| Action | When to use it | What happens |
|---|---|---|
| **Steer** | The work is heading the wrong way, or you know something Ysra doesn't. | Your message is queued and applied at the next checkpoint, without restarting. |
| **Answer** | Ysra asked you a question and is waiting. | The answer unblocks exactly that question. Answers are kept separate from steering, so they never change the scope by accident. |
| **Interrupt / resume** | You need it to stop for now. | Work pauses at a safe point and resumes from the last checkpoint. |
| **Cancel** | You no longer want the result. | The session ends; the work so far stays inspectable. |
| **Continue / retry** | A session stopped on a boundary — budget, time, a transient failure. | It resumes with the same goal and the same candidate, not a fresh start. |
| **Extend budget** | It stopped at its ceiling and the work is worth finishing. | The ceiling rises by what you choose; the session continues. |
| **Update permissions** | It asked to install a package or use the network. | Approve once, or change the repository's [policy](../workspace/autonomy-policy.md). |
| **Ask about the evidence** | You want to understand a result. | Ysra answers from the session's recorded evidence — "why did the test fail?" — without doing new work. |
| **Rewind** | A later change made things worse. | The candidate returns to an exact earlier checkpoint. |
| **Preview** | You want to click through it. | See [Previews](previews.md). |

### Steering well

Steering works best when it is specific and early:

> Use the existing `DateRange` type rather than a new one.

> Don't touch the checkout module — the bug is in the cart.

Up to three steering messages can wait in the queue at once. Each is marked
*applied* only once a checkpoint has recorded it, so nothing you said can be
silently lost to a restart.

## Checkpoints

A **checkpoint** is a saved, exact version of the work: the candidate, the plan,
what has been checked, and the conversation so far. Sessions create them as they
go — after implementation steps, after verification, after review.

Checkpoints are what make Ysra safe to interrupt:

- **Resuming** after an interruption continues from the latest checkpoint with
  everything already established — it doesn't start over or forget.
- **Long jobs** run in slices; each slice ends at a checkpoint and the next picks
  up from it.
- **Crashes** are recoverable: another worker resumes from the checkpoint, not
  from memory.

## Rewinding

Open the checkpoint list for a session to see each version, labelled by what
happened there — implementation, verification, review — with its diff.

When you rewind:

1. The exact candidate from that checkpoint is restored, byte for byte. Ysra
   never "re-creates" old work from a description.
2. The restored version becomes the newest version, and is marked
   **unverified** — the checks and reviews that ran later described different
   code, so they no longer count.
3. Continue from there: steer, re-run checks, or deliver.

Some checkpoints can't be rewound to — for example, a task inside a
[Project](projects.md) that has already been integrated with others. The list
tells you why.

## When a session stops by itself

A session stops rather than loop when:

- **the budget is reached** — it asks before the next paid step;
- **the same failure repeats with no progress** — it keeps the candidate and
  explains what is blocking it;
- **it needs a decision only you can make**;
- **something outside the code failed** — a revoked permission, an unreachable
  service. It waits for the outside change instead of rewriting working code.

In every case the candidate, the checkpoints and the evidence are kept. A
materially different instruction from you is usually all it takes to continue.