# `settings_changed`

**Status 409.** The programme changed after it was read, so nothing was changed.

## What it means

The programme was changed after the reading this change was built over: the one named by your `if_version`, or the one the API made itself to build the change, so that a change made in your Shopify admin or by another key in between is never quietly undone. Nothing was changed.

## What to do

Read the programme again with [`GET /stores/{store_key}/programme`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#getProgramme), check the change still makes sense against it, and send it with a new `Idempotency-Key`.

## Safe to send again?

Not as it is. Change what the answer points to, then send the request.

## Where you can meet it

- [`POST /stores/{store_key}/programme`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#updateProgramme): Change the earn rate, the bonuses, what a point is worth, referrals, spending any amount, the time zone, the ways to earn, or when points expire
- [`POST /stores/{store_key}/programme/rewards`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#addReward): Add a reward shoppers can spend points on
- [`POST /stores/{store_key}/programme/rewards/{reward_id}`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#changeReward): Change a reward's cost, value, minimum order or label
- [`POST /stores/{store_key}/programme/rewards/{reward_id}/remove`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#removeReward): Remove a reward
- [`POST /stores/{store_key}/programme/offers`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#addOffer): Add an offer: a campaign, a product offer or a channel offer
- [`POST /stores/{store_key}/programme/offers/{offer_id}`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#changeOffer): Change an offer
- [`POST /stores/{store_key}/programme/offers/{offer_id}/remove`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#removeOffer): Remove an offer
- [`POST /stores/{store_key}/design`](https://matrixrewards.co.uk/docs/api/2026-10/stores.md#updateDesign): Change the design: colours, words, the panel and product-line look, the account page layout, the terms link

Every code, and the shape of an error answer: [Errors](https://matrixrewards.co.uk/docs/errors.md).

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Page: https://matrixrewards.co.uk/docs/errors/settings_changed
Contract: 2026-10 sha256:35af153960028890fea5738799f5a71e535e1eea4dd3f6b8d5f50b37f02363da