## Issue Addressed
Closes#3896Closes#3998Closes#3700
## Proposed Changes
- Optimise the calculation of withdrawals for payload attributes by avoiding state clones, avoiding unnecessary state advances and reading from the snapshot cache if possible.
- Use the execution layer's payload attributes cache to avoid re-calculating payload attributes. I actually implemented a new LRU cache just for withdrawals but it had the exact same key and most of the same data as the existing payload attributes cache, so I deleted it.
- Add a new SSE event that fires when payloadAttributes are calculated. This is useful for block builders, a la https://github.com/ethereum/beacon-APIs/issues/244.
- Add a new CLI flag `--always-prepare-payload` which forces payload attributes to be sent with every fcU regardless of connected proposers. This is intended for use by builders/relays.
For maximum effect, the flags I've been using to run Lighthouse in "payload builder mode" are:
```
--always-prepare-payload \
--prepare-payload-lookahead 12000 \
--suggested-fee-recipient 0x0000000000000000000000000000000000000000
```
The fee recipient is required so Lighthouse has something to pack in the payload attributes (it can be ignored by the builder). The lookahead causes fcU to be sent at the start of every slot rather than at 8s. As usual, fcU will also be sent after each change of head block. I think this combination is sufficient for builders to build on all viable heads. Often there will be two fcU (and two payload attributes) sent for the same slot: one sent at the start of the slot with the head from `n - 1` as the parent, and one sent after the block arrives with `n` as the parent.
Example usage of the new event stream:
```bash
curl -N "http://localhost:5052/eth/v1/events?topics=payload_attributes"
```
## Additional Info
- [x] Tests added by updating the proposer re-org tests. This has the benefit of testing the proposer re-org code paths with withdrawals too, confirming that the new changes don't interact poorly.
- [ ] Benchmarking with `blockdreamer` on devnet-7 showed promising results but I'm yet to do a comparison to `unstable`.
Co-authored-by: Michael Sproul <micsproul@gmail.com>
## Issue Addressed
Cleans up all the remnants of 4844 in capella. This makes sure when 4844 is reviewed there is nothing we are missing because it got included here
## Proposed Changes
drop a bomb on every 4844 thing
## Additional Info
Merge process I did (locally) is as follows:
- squash merge to produce one commit
- in new branch off unstable with the squashed commit create a `git revert HEAD` commit
- merge that new branch onto 4844 with `--strategy ours`
- compare local 4844 to remote 4844 and make sure the diff is empty
- enjoy
Co-authored-by: Paul Hauner <paul@paulhauner.com>
* Import BLS to execution changes before Capella
* Test for BLS to execution change HTTP API
* Pack BLS to execution changes in LIFO order
* Remove unused var
* Clippy
## Summary
The deposit cache now has the ability to finalize deposits. This will cause it to drop unneeded deposit logs and hashes in the deposit Merkle tree that are no longer required to construct deposit proofs. The cache is finalized whenever the latest finalized checkpoint has a new `Eth1Data` with all deposits imported.
This has three benefits:
1. Improves the speed of constructing Merkle proofs for deposits as we can just replay deposits since the last finalized checkpoint instead of all historical deposits when re-constructing the Merkle tree.
2. Significantly faster weak subjectivity sync as the deposit cache can be transferred to the newly syncing node in compressed form. The Merkle tree that stores `N` finalized deposits requires a maximum of `log2(N)` hashes. The newly syncing node then only needs to download deposits since the last finalized checkpoint to have a full tree.
3. Future proofing in preparation for [EIP-4444](https://eips.ethereum.org/EIPS/eip-4444) as execution nodes will no longer be required to store logs permanently so we won't always have all historical logs available to us.
## More Details
Image to illustrate how the deposit contract merkle tree evolves and finalizes along with the resulting `DepositTreeSnapshot`
## Other Considerations
I've changed the structure of the `SszDepositCache` so once you load & save your database from this version of lighthouse, you will no longer be able to load it from older versions.
Co-authored-by: ethDreamer <37123614+ethDreamer@users.noreply.github.com>
* add capella gossip boiler plate
* get everything compiling
Co-authored-by: realbigsean <sean@sigmaprime.io
Co-authored-by: Mark Mackey <mark@sigmaprime.io>
* small cleanup
* small cleanup
* cargo fix + some test cleanup
* improve block production
* add fixme for potential panic
Co-authored-by: Mark Mackey <mark@sigmaprime.io>
## Issue Addressed
https://github.com/ethereum/beacon-APIs/pull/222
## Proposed Changes
Update Lighthouse's randao verification API to match the `beacon-APIs` spec. We implemented the API before spec stabilisation, and it changed slightly in the course of review.
Rather than a flag `verify_randao` taking a boolean value, the new API uses a `skip_randao_verification` flag which takes no argument. The new spec also requires the randao reveal to be present and equal to the point-at-infinity when `skip_randao_verification` is set.
I've also updated the `POST /lighthouse/analysis/block_rewards` API to take blinded blocks as input, as the execution payload is irrelevant and we may want to assess blocks produced by builders.
## Additional Info
This is technically a breaking change, but seeing as I suspect I'm the only one using these parameters/APIs, I think we're OK to include this in a patch release.
## Issue Addressed
[Have --checkpoint-sync-url timeout](https://github.com/sigp/lighthouse/issues/3478)
## Proposed Changes
I added a parameter for `get_bytes_opt_accept_header<U: IntoUrl>` which accept a timeout duration, and modified the body of `get_beacon_blocks_ssz` and `get_debug_beacon_states_ssz` to pass corresponding timeout durations.
## Issue Addressed
NA
## Proposed Changes
As we've seen on Prater, there seems to be a correlation between these messages
```
WARN Not enough time for a discovery search subnet_id: ExactSubnet { subnet_id: SubnetId(19), slot: Slot(3742336) }, service: attestation_service
```
... and nodes falling 20-30 slots behind the head for short periods. These nodes are running ~20k Prater validators.
After running some metrics, I can see that the `network_recv` channel is processing ~250k `AttestationSubscribe` messages per minute. It occurred to me that perhaps the `AttestationSubscribe` messages are "washing out" the `SendRequest` and `SendResponse` messages. In this PR I separate the `AttestationSubscribe` and `SyncCommitteeSubscribe` messages into their own queue so the `tokio::select!` in the `NetworkService` can still process the other messages in the `network_recv` channel without necessarily having to clear all the subscription messages first.
~~I've also added filter to the HTTP API to prevent duplicate subscriptions going to the network service.~~
## Additional Info
- Currently being tested on Prater
## Issue Addressed
Resolves#3388Resolves#2638
## Proposed Changes
- Return the `BellatrixPreset` on `/eth/v1/config/spec` by default.
- Allow users to opt out of this by providing `--http-spec-fork=altair` (unless there's a Bellatrix fork epoch set).
- Add the Altair constants from #2638 and make serving the constants non-optional (the `http-disable-legacy-spec` flag is deprecated).
- Modify the VC to only read the `Config` and not to log extra fields. This prevents it from having to muck around parsing the `ConfigAndPreset` fields it doesn't need.
## Additional Info
This change is backwards-compatible for the VC and the BN, but is marked as a breaking change for the removal of `--http-disable-legacy-spec`.
I tried making `Config` a `superstruct` too, but getting the automatic decoding to work was a huge pain and was going to require a lot of hacks, so I gave up in favour of keeping the default-based approach we have now.
## Issue Addressed
NA
## Proposed Changes
Modifies `lcli skip-slots` and `lcli transition-blocks` allow them to source blocks/states from a beaconAPI and also gives them some more features to assist with benchmarking.
## Additional Info
Breaks the current `lcli skip-slots` and `lcli transition-blocks` APIs by changing some flag names. It should be simple enough to figure out the changes via `--help`.
Currently blocked on #3263.
## Issue Addressed
https://github.com/status-im/nimbus-eth2/issues/3930
## Proposed Changes
We can trivially support beacon nodes which do not provide the `is_optimistic` field by wrapping the field in an `Option`.
## Issue Addressed
https://github.com/sigp/lighthouse/issues/3091
Extends https://github.com/sigp/lighthouse/pull/3062, adding pre-bellatrix block support on blinded endpoints and allowing the normal proposal flow (local payload construction) on blinded endpoints. This resulted in better fallback logic because the VC will not have to switch endpoints on failure in the BN <> Builder API, the BN can just fallback immediately and without repeating block processing that it shouldn't need to. We can also keep VC fallback from the VC<>BN API's blinded endpoint to full endpoint.
## Proposed Changes
- Pre-bellatrix blocks on blinded endpoints
- Add a new `PayloadCache` to the execution layer
- Better fallback-from-builder logic
## Todos
- [x] Remove VC transition logic
- [x] Add logic to only enable builder flow after Merge transition finalization
- [x] Tests
- [x] Fix metrics
- [x] Rustdocs
Co-authored-by: Mac L <mjladson@pm.me>
Co-authored-by: realbigsean <sean@sigmaprime.io>
## Issue Addressed
As specified in the [Beacon Chain API specs](https://github.com/ethereum/beacon-APIs/blob/master/apis/node/syncing.yaml#L32-L35) we should return `is_optimistic` as part of the response to a query for the `eth/v1/node/syncing` endpoint.
## Proposed Changes
Compute the optimistic status of the head and add it to the `SyncingData` response.
## Issue Addressed
#3031
## Proposed Changes
Updates the following API endpoints to conform with https://github.com/ethereum/beacon-APIs/pull/190 and https://github.com/ethereum/beacon-APIs/pull/196
- [x] `beacon/states/{state_id}/root`
- [x] `beacon/states/{state_id}/fork`
- [x] `beacon/states/{state_id}/finality_checkpoints`
- [x] `beacon/states/{state_id}/validators`
- [x] `beacon/states/{state_id}/validators/{validator_id}`
- [x] `beacon/states/{state_id}/validator_balances`
- [x] `beacon/states/{state_id}/committees`
- [x] `beacon/states/{state_id}/sync_committees`
- [x] `beacon/headers`
- [x] `beacon/headers/{block_id}`
- [x] `beacon/blocks/{block_id}`
- [x] `beacon/blocks/{block_id}/root`
- [x] `beacon/blocks/{block_id}/attestations`
- [x] `debug/beacon/states/{state_id}`
- [x] `debug/beacon/heads`
- [x] `validator/duties/attester/{epoch}`
- [x] `validator/duties/proposer/{epoch}`
- [x] `validator/duties/sync/{epoch}`
Updates the following Server-Sent Events:
- [x] `events?topics=head`
- [x] `events?topics=block`
- [x] `events?topics=finalized_checkpoint`
- [x] `events?topics=chain_reorg`
## Backwards Incompatible
There is a very minor breaking change with the way the API now handles requests to `beacon/blocks/{block_id}/root` and `beacon/states/{state_id}/root` when `block_id` or `state_id` is the `Root` variant of `BlockId` and `StateId` respectively.
Previously a request to a non-existent root would simply echo the root back to the requester:
```
curl "http://localhost:5052/eth/v1/beacon/states/0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/root"
{"data":{"root":"0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"}}
```
Now it will return a `404`:
```
curl "http://localhost:5052/eth/v1/beacon/blocks/0xaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa/root"
{"code":404,"message":"NOT_FOUND: beacon block with root 0xaaaa…aaaa","stacktraces":[]}
```
In addition to this is the block root `0x0000000000000000000000000000000000000000000000000000000000000000` previously would return the genesis block. It will now return a `404`:
```
curl "http://localhost:5052/eth/v1/beacon/blocks/0x0000000000000000000000000000000000000000000000000000000000000000"
{"code":404,"message":"NOT_FOUND: beacon block with root 0x0000…0000","stacktraces":[]}
```
## Additional Info
- `execution_optimistic` is always set, and will return `false` pre-Bellatrix. I am also open to the idea of doing something like `#[serde(skip_serializing_if = "Option::is_none")]`.
- The value of `execution_optimistic` is set to `false` where possible. Any computation that is reliant on the `head` will simply use the `ExecutionStatus` of the head (unless the head block is pre-Bellatrix).
Co-authored-by: Paul Hauner <paul@paulhauner.com>
## Issue Addressed
Resolves#3276.
## Proposed Changes
Add a timeout for the sync committee contributions at 1/4 the slot length such that we may be able to try backup beacon nodes in the case of contribution post failure.
## Additional Info
1/4 slot length seemed standard for the timeouts, but may want to decrease this to 1/2.
I did not find any timeout related / sync committee related tests, so there are no tests. Happy to write some with a bit of guidance.
## Issue Addressed
* #3173
## Proposed Changes
Moved all `fee_recipient_file` related logic inside the `ValidatorStore` as it makes more sense to have this all together there. I tested this with the validators I have on `mainnet-shadow-fork-5` and everything appeared to work well. Only technicality is that I can't get the method to return `401` when the authorization header is not specified (it returns `400` instead). Fixing this is probably quite difficult given that none of `warp`'s rejections have code `401`.. I don't really think this matters too much though as long as it fails.
## Issue Addressed
This PR is a subset of the changes in #3134. Unstable will still not function correctly with the new builder spec once this is merged, #3134 should be used on testnets
## Proposed Changes
- Removes redundancy in "builders" (servers implementing the builder spec)
- Renames `payload-builder` flag to `builder`
- Moves from old builder RPC API to new HTTP API, but does not implement the validator registration API (implemented in https://github.com/sigp/lighthouse/pull/3194)
Co-authored-by: sean <seananderson33@gmail.com>
Co-authored-by: realbigsean <sean@sigmaprime.io>
## Issue Addressed
Lays the groundwork for builder API changes by implementing the beacon-API's new `register_validator` endpoint
## Proposed Changes
- Add a routine in the VC that runs on startup (re-try until success), once per epoch or whenever `suggested_fee_recipient` is updated, signing `ValidatorRegistrationData` and sending it to the BN.
- TODO: `gas_limit` config options https://github.com/ethereum/builder-specs/issues/17
- BN only sends VC registration data to builders on demand, but VC registration data *does update* the BN's prepare proposer cache and send an updated fcU to a local EE. This is necessary for fee recipient consistency between the blinded and full block flow in the event of fallback. Having the BN only send registration data to builders on demand gives feedback directly to the VC about relay status. Also, since the BN has no ability to sign these messages anyways (so couldn't refresh them if it wanted), and validator registration is independent of the BN head, I think this approach makes sense.
- Adds upcoming consensus spec changes for this PR https://github.com/ethereum/consensus-specs/pull/2884
- I initially applied the bit mask based on a configured application domain.. but I ended up just hard coding it here instead because that's how it's spec'd in the builder repo.
- Should application mask appear in the api?
Co-authored-by: realbigsean <sean@sigmaprime.io>
## Proposed Changes
Add a new HTTP endpoint `POST /lighthouse/analysis/block_rewards` which takes a vec of `BeaconBlock`s as input and outputs the `BlockReward`s for them.
Augment the `BlockReward` struct with the attestation data for attestations in the block, which simplifies access to this information from blockprint. Using attestation data I've been able to make blockprint up to 95% accurate across Prysm/Lighthouse/Teku/Nimbus. I hope to go even higher using a bunch of synthetic blocks produced for Prysm/Nimbus/Lodestar, which are underrepresented in the current training data.
## Issue Addressed
Web3Signer validators do not support client authentication. This means the `--tls-known-clients-file` option on Web3Signer can't be used with Lighthouse.
## Proposed Changes
Add two new fields to Web3Signer validators, `client_identity_path` and `client_identity_password`, which specify the path and password for a PKCS12 file containing a certificate and private key. If `client_identity_path` is present, use the certificate for SSL client authentication.
## Additional Info
I am successfully validating on Prater using client authentication with Web3Signer and client authentication.
## Issue Addressed
Which issue # does this PR address?
#3114
## Proposed Changes
1. introduce `mime` package
2. Parse `Accept` field in the header with `mime`
## Additional Info
Please provide any additional information. For example, future considerations
or information useful for reviewers.
## Issue Addressed
#3068
## Proposed Changes
Adds support for remote key API.
## Additional Info
Needed to add `is_local_keystore` argument to `delete_definition_and_keystore` to know if we want to delete local or remote key. Previously this wasn't necessary because remotekeys(web3signers) could be deleted.
## Proposed Changes
I did some gardening 🌳 in our dependency tree:
- Remove duplicate versions of `warp` (git vs patch)
- Remove duplicate versions of lots of small deps: `cpufeatures`, `ethabi`, `ethereum-types`, `bitvec`, `nix`, `libsecp256k1`.
- Update MDBX (should resolve#3028). I tested and Lighthouse compiles on Windows 11 now.
- Restore `psutil` back to upstream
- Make some progress updating everything to rand 0.8. There are a few crates stuck on 0.7.
Hopefully this puts us on a better footing for future `cargo audit` issues, and improves compile times slightly.
## Additional Info
Some crates are held back by issues with `zeroize`. libp2p-noise depends on [`chacha20poly1305`](https://crates.io/crates/chacha20poly1305) which depends on zeroize < v1.5, and we can only have one version of zeroize because it's post 1.0 (see https://github.com/rust-lang/cargo/issues/6584). The latest version of `zeroize` is v1.5.4, which is used by the new versions of many other crates (e.g. `num-bigint-dig`). Once a new version of chacha20poly1305 is released we can update libp2p-noise and upgrade everything to the latest `zeroize` version.
I've also opened a PR to `blst` related to zeroize: https://github.com/supranational/blst/pull/111
## Proposed Changes
Increase the default `--slots-per-restore-point` to 8192 for a 4x reduction in freezer DB disk usage.
Existing nodes that use the previous default of 2048 will be left unchanged. Newly synced nodes (with or without checkpoint sync) will use the new 8192 default.
Long-term we could do away with the freezer DB entirely for validator-only nodes, but this change is much simpler and grants us some extra space in the short term. We can also roll it out gradually across our nodes by purging databases one by one, while keeping the Ansible config the same.
## Additional Info
We ignore a change from 2048 to 8192 if the user hasn't set the 8192 explicitly. We fire a debug log in the case where we do ignore:
```
DEBG Ignoring slots-per-restore-point config in favour of on-disk value, on_disk: 2048, config: 8192
```
## Issue Addressed
MEV boost compatibility
## Proposed Changes
See #2987
## Additional Info
This is blocked on the stabilization of a couple specs, [here](https://github.com/ethereum/beacon-APIs/pull/194) and [here](https://github.com/flashbots/mev-boost/pull/20).
Additional TODO's and outstanding questions
- [ ] MEV boost JWT Auth
- [ ] Will `builder_proposeBlindedBlock` return the revealed payload for the BN to propogate
- [ ] Should we remove `private-tx-proposals` flag and communicate BN <> VC with blinded blocks by default once these endpoints enter the beacon-API's repo? This simplifies merge transition logic.
Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: realbigsean <sean@sigmaprime.io>
## Proposed Changes
Allow Lighthouse to speculatively create blocks via the `/eth/v1/validators/blocks` endpoint by optionally skipping the RANDAO verification that we introduced in #2740. When `verify_randao=false` is passed as a query parameter the `randao_reveal` is not required to be present, and if present will only be lightly checked (must be a valid BLS sig). If `verify_randao` is omitted it defaults to true and Lighthouse behaves exactly as it did previously, hence this PR is backwards-compatible.
I'd like to get this change into `unstable` pretty soon as I've got 3 projects building on top of it:
- [`blockdreamer`](https://github.com/michaelsproul/blockdreamer), which mocks block production every slot in order to fingerprint clients
- analysis of Lighthouse's block packing _optimality_, which uses `blockdreamer` to extract interesting instances of the attestation packing problem
- analysis of Lighthouse's block packing _performance_ (as in speed) on the `tree-states` branch
## Additional Info
Having tested `blockdreamer` with Prysm, Nimbus and Teku I noticed that none of them verify the randao signature on `/eth/v1/validator/blocks`. I plan to open a PR to the `beacon-APIs` repo anyway so that this parameter can be standardised in case the other clients add RANDAO verification by default in future.
## Proposed Changes
Lots of lint updates related to `flat_map`, `unwrap_or_else` and string patterns. I did a little more creative refactoring in the op pool, but otherwise followed Clippy's suggestions.
## Additional Info
We need this PR to unblock CI.
## Issue Addressed
N/A
## Proposed Changes
Add a HTTP API which can be used to compute the block packing data for all blocks over a discrete range of epochs.
## Usage
### Request
```
curl "http:localhost:5052/lighthouse/analysis/block_packing_efficiency?start_epoch=57730&end_epoch=57732"
```
### Response
```
[
{
"slot": "1847360",
"block_hash": "0xa7dc230659802df2f99ea3798faede2e75942bb5735d56e6bfdc2df335dcd61f",
"proposer_info": {
"validator_index": 1686,
"graffiti": ""
},
"available_attestations": 7096,
"included_attestations": 6459,
"prior_skip_slots": 0
},
...
]
```
## Additional Info
This is notably different to the existing lcli code:
- Uses `BlockReplayer` #2863 and as such runs significantly faster than the previous method.
- Corrects the off-by-one #2878
- Removes the `offline` validators component. This was only a "best guess" and simply was used as a way to determine an estimate of the "true" packing efficiency and was generally not helpful in terms of direct comparisons between different packing methods. As such it has been removed from the API and any future estimates of "offline" validators would be better suited in a separate/more targeted API or as part of 'beacon watch': #2873
- Includes `prior_skip_slots`.
## Issue Addressed
#2883
## Proposed Changes
* Added `suggested-fee-recipient` & `suggested-fee-recipient-file` flags to validator client (similar to graffiti / graffiti-file implementation).
* Added proposer preparation service to VC, which sends the fee-recipient of all known validators to the BN via [/eth/v1/validator/prepare_beacon_proposer](https://github.com/ethereum/beacon-APIs/pull/178) api once per slot
* Added [/eth/v1/validator/prepare_beacon_proposer](https://github.com/ethereum/beacon-APIs/pull/178) api endpoint and preparation data caching
* Added cleanup routine to remove cached proposer preparations when not updated for 2 epochs
## Additional Info
Changed the Implementation following the discussion in #2883.
Co-authored-by: pk910 <philipp@pk910.de>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
Co-authored-by: Philipp K <philipp@pk910.de>
## Issue Addressed
Implements the standard key manager API from https://ethereum.github.io/keymanager-APIs/, formerly https://github.com/ethereum/beacon-APIs/pull/151
Related to https://github.com/sigp/lighthouse/issues/2557
## Proposed Changes
- [x] Add all of the new endpoints from the standard API: GET, POST and DELETE.
- [x] Add a `validators.enabled` column to the slashing protection database to support atomic disable + export.
- [x] Add tests for all the common sequential accesses of the API
- [x] Add tests for interactions with remote signer validators
- [x] Add end-to-end tests for migration of validators from one VC to another
- [x] Implement the authentication scheme from the standard (token bearer auth)
## Additional Info
The `enabled` column in the validators SQL database is necessary to prevent a race condition when exporting slashing protection data. Without the slashing protection database having a way of knowing that a key has been disabled, a concurrent request to sign a message could insert a new record into the database. The `delete_concurrent_with_signing` test exercises this code path, and was indeed failing before the `enabled` column was added.
The validator client authentication has been modified from basic auth to bearer auth, with basic auth preserved for backwards compatibility.
## Issue Addressed
N/A
## Proposed Changes
Add a HTTP API which can be used to compute the attestation performances of a validator (or all validators) over a discrete range of epochs.
Performances can be computed for a single validator, or for the global validator set.
## Usage
### Request
The API can be used as follows:
```
curl "http://localhost:5052/lighthouse/analysis/attestation_performance/{validator_index}?start_epoch=57730&end_epoch=57732"
```
Alternatively, to compute performances for the global validator set:
```
curl "http://localhost:5052/lighthouse/analysis/attestation_performance/global?start_epoch=57730&end_epoch=57732"
```
### Response
The response is JSON formatted as follows:
```
[
{
"index": 72,
"epochs": {
"57730": {
"active": true,
"head": false,
"target": false,
"source": false
},
"57731": {
"active": true,
"head": true,
"target": true,
"source": true,
"delay": 1
},
"57732": {
"active": true,
"head": true,
"target": true,
"source": true,
"delay": 1
},
}
}
]
```
> Note that the `"epochs"` are not guaranteed to be in ascending order.
## Additional Info
- This API is intended to be used in our upcoming validator analysis tooling (#2873) and will likely not be very useful for regular users. Some advanced users or block explorers may find this API useful however.
- The request range is limited to 100 epochs (since the range is inclusive and it also computes the `end_epoch` it's actually 101 epochs) to prevent Lighthouse using exceptionally large amounts of memory.
