---
title: "Fetch packed slabs for upload"
method: POST
path: "/bus/slabbuffer/fetch"
tags: ["bus"]
---

# Fetch packed slabs for upload

`POST /bus/slabbuffer/fetch`

Returns packed slabs that are ready to be uploaded.

## Request body

- object
  - `lockingDuration` integer — Duration in milliseconds to lock the slabs
  - `minShards` integer — The number of data shards a piece of an object gets erasure-coded into
  - `totalShards` integer — The number of total data shards a piece of an object gets erasure-coded into
  - `limit` integer — Maximum number of packed slabs to return

## Response `200`

Successfully retrieved packed slabs

- PackedSlab[]
  - `bufferID` integer — ID of the buffer containing the slab
  - `data` string, binary — The slab data
  - `encryptionKey` string — A key used to encrypt and decrypt data. The key is either a regular key (key) or a salted key (skey). The latter requires a seed to be used for encryption and decryption.

## Other responses

- `500` — Internal server error

## Changes

- **2025-01-23** `c38282599c5a` — 2 warning, 2 info
  - the `minShards` request property's min was set to `1.00`
  - the `totalShards` request property's min was set to `2.00`
  - the `minShards` request property default value `10` was added
  - the `totalShards` request property default value `30` was added
- **2024-12-18** `922f156353c9` — 1 breaking, 1 info
  - removed the media type `text/plain` for the response with the status `500`
  - api tag `bus` added
- **2024-12-17** `593be511b682` — 1 info
  - endpoint added
- **2024-12-09** `f062c35d8f47` — 1 breaking
  - api path removed without deprecation

[Change history](https://skmtc.dev/siafoundation/apis/renterd-api/changes/bus/slabbuffer/fetch/post.md)

---

[API](https://skmtc.dev/siafoundation/apis/renterd-api.md) · [All operations](https://skmtc.dev/siafoundation/apis/renterd-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/siafoundation/renterd-api/revisions/184a3d5207da/schema)