> ## Documentation Index
> Fetch the complete documentation index at: https://docs.beaconcha.in/llms.txt
> Use this file to discover all available pages before exploring further.

# Glamsterdam API (experimental)

> Try the API for the Glamsterdam hard fork on Hoodi before it reaches mainnet

Glamsterdam is the next Ethereum hard fork: **Gloas** on the consensus layer, which brings enshrined proposer-builder separation (EIP-7732), and **Amsterdam** on the execution layer. Hoodi forks first. Its fork, planned for 2026-10-26, was postponed and has no new date yet. Mainnet has no fork date yet either.

We publish the API for it early, so you can build against real Hoodi data and tell us what you need before mainnet forks.

> [!WARNING]
>
> Everything on this page is experimental. Endpoints and fields may change before the mainnet release, including breaking changes. We publish the final API before the mainnet fork and announce it in the changelog.

## What experimental means

* Data exists only on chains past the fork. Send `"chain": "hoodi"`.
* On a chain that has not forked, experimental endpoints return `404` and experimental fields are `null`.
* The request and response may change until the final API is published.
* Experimental endpoints carry an **Experimental** tag in the sidebar.

## Experimental endpoints

This list is not complete. We add more Glamsterdam endpoints and fields between the Hoodi fork and the mainnet fork, and list each one here when it ships.

| Endpoint | Returns |
| - | - |
| [`POST /api/v2/ethereum/validators/ptc-slots`](https://docs.beaconcha.in/api-reference/ethereum/validators/ptc-slots) | The slots where your validators held a Payload Timeliness Committee position, and how many of those positions voted |
| [`POST /api/v2/ethereum/slot/ptc-duties`](https://docs.beaconcha.in/api-reference/ethereum/slot/ptc-duties) | Every Payload Timeliness Committee position of one slot, which validator held it, and its vote |

## Experimental fields on existing endpoints

Only the fields below are experimental. The rest of each endpoint is stable, apart from the fields in the next section.

| Endpoint | Fields |
| - | - |
| [`POST /api/v2/ethereum/slot`](https://docs.beaconcha.in/api-reference/ethereum/slot/overview) | `payload_status`, `empty_reason` |
| [`POST /api/v2/ethereum/epoch`](https://docs.beaconcha.in/api-reference/ethereum/epoch/overview) | `ptc_participation` |
| [`POST /api/v2/ethereum/validators/performance-aggregate`](https://docs.beaconcha.in/api-reference/ethereum/validators/performance-aggregate) | `ptc` in the duties |
| [`POST /api/v2/ethereum/validators/performance-list`](https://docs.beaconcha.in/api-reference/ethereum/validators/performance-list) | `ptc` in the duties |
| [`POST /api/v2/ethereum/performance-aggregate`](https://docs.beaconcha.in/api-reference/ethereum/performance-aggregate) | `ptc` in the duties |

## Fields whose meaning changes at the fork

These fields keep their name but carry a different meaning from the Glamsterdam fork on. Each field description explains both meanings.

| Endpoint | Fields | Status |
| - | - | - |
| [`POST /api/v2/ethereum/block/rewards`](https://docs.beaconcha.in/api-reference/ethereum/block/rewards) | `total_reward`, `mev` | Experimental: the post-fork meaning may change |
| [`POST /api/v2/ethereum/block/mev-timing`](https://docs.beaconcha.in/api-reference/ethereum/block/mev-timing), [`POST /api/v2/ethereum/mev-timing`](https://docs.beaconcha.in/api-reference/ethereum/mev-timing), [`POST /api/v2/ethereum/entity/mev-timing`](https://docs.beaconcha.in/api-reference/ethereum/entity/mev-timing), [`POST /api/v2/ethereum/validators/mev-timing-aggregate`](https://docs.beaconcha.in/api-reference/ethereum/validators/mev-timing-aggregate) | `status` is `not_applicable` after the fork | Final |
| [`POST /api/v2/ethereum/block/mev-bids`](https://docs.beaconcha.in/api-reference/ethereum/block/mev-bids) | bid arrival times no longer measure proposer timing | Final |
| [`POST /api/v2/ethereum/slot/consolidations`](https://docs.beaconcha.in/api-reference/ethereum/consolidations) | `consensus_layer_queued` in `stage_history` | Final |

## Feedback

Tell us what works, what is missing, and what you would change at [support@beaconcha.in](mailto:support@beaconcha.in).


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.