---
title: "Submit a microblock (Epoch 2.x)"
method: POST
path: "/v2/microblocks"
tags: ["Blocks", "Microblocks"]
---

# Submit a microblock (Epoch 2.x)

`POST /v2/microblocks`

Submit a microblock to the node for validation and relay.
The body **must** be the SIP-003 binary serialization of a `Microblock`
and sent with `Content-Type: application/octet-stream`.

## Response `200`

Index-block hash of the accepted microblock

- string — 32-byte block-header hash (hex)

## Other responses

- `400` — Bad request
- `404` — Not found
- `500` — Internal Server Error

## Changes

- **2026-01-28** `30468ca2533f` — 1 breaking
  - the request's body minLength was increased from `0` to `1`
- **2026-01-14** `f7f733b4a1fc` — 1 info
  - the request's body minLength was decreased from `1` to `0`
- **2026-01-14** `eb2153a4a3ad` — 1 breaking
  - the request's body minLength was increased from `0` to `1`
- **2026-01-02** `96224b968a3e` — 1 info
  - the request's body minLength was decreased from `1` to `0`
- **2025-12-18** `97e7080a8130` — 1 breaking
  - the request's body minLength was increased from `0` to `1`

[Full history](https://skmtc.dev/stacks-network/apis/stacks-3-0-rpc-api/changes/v2/microblocks/post.md)

---

[API](https://skmtc.dev/stacks-network/apis/stacks-3-0-rpc-api.md) · [All operations](https://skmtc.dev/stacks-network/apis/stacks-3-0-rpc-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/stacks-network/stacks-3-0-rpc-api/revisions/bfe6e0b30f62/schema)