# Relays **URL:** https://collective.flashbots.net/c/relays/15.md [Latest](https://collective.flashbots.net/latest.md) · [Categories](https://collective.flashbots.net/categories.md) · [Tags](https://collective.flashbots.net/tags.md) --- ## [About the Relays category](https://collective.flashbots.net/t/about-the-relays-category/125)
**Author:** [@guayabyte](https://collective.flashbots.net/u/guayabyte)\ **Replies:** 0\ **Last updated:** [August 17, 2022, 4:24pm UTC](https://collective.flashbots.net/t/about-the-relays-category/125 "2022-08-17T16:24:01Z")
Relays are a trusted communication interface between block builders and proposers that validates and routes execution payloads. Resources: :page\_facing\_up: Documentation: docs.flashbots.net/flashbots-mev-boost/relay … --- ## [Is the Sepolia relay behind a policy/whitelist? ](https://collective.flashbots.net/t/is-the-sepolia-relay-behind-a-policy-whitelist/5496)
**Author:** [@carlos23](https://collective.flashbots.net/u/carlos23)\ **Replies:** 0\ **Last updated:** [January 18, 2026, 11:43am UTC](https://collective.flashbots.net/t/is-the-sepolia-relay-behind-a-policy-whitelist/5496 "2026-01-18T11:43:37Z")
I’m getting signature is required / invalid flashbots signature from https://relay-sepolia.flashbots.net even with the official SDK and minimal payload. It does verifies the signature against the Mainnet relay though. I… --- ## ["signature is required" error occurs always!](https://collective.flashbots.net/t/signature-is-required-error-occurs-always/5495)
**Author:** [@simonjin](https://collective.flashbots.net/u/simonjin)\ **Replies:** 0\ **Last updated:** [January 18, 2026, 11:43am UTC](https://collective.flashbots.net/t/signature-is-required-error-occurs-always/5495 "2026-01-18T11:43:33Z")
Kindly check this code below. const { Wallet, JsonRpcProvider, id, getBytes, FetchRequest } = require('ethers'); async function send(relayUrl, body, header) { const req = new FetchRequest(relayUrl); req.setHeader('… --- ## [HTTP Status 400: Invalid Signature](https://collective.flashbots.net/t/http-status-400-invalid-signature/3220)
**Author:** [@mcryptid](https://collective.flashbots.net/u/mcryptid)\ **Replies:** 4\ **Last updated:** [September 18, 2024, 1:03am UTC](https://collective.flashbots.net/t/http-status-400-invalid-signature/3220 "2024-09-18T01:03:15Z")
Are there any known issues with mev-boost-relay related to invalid signatures a la https://collective.flashbots.net/t/impact-of-the-prysm-invalid-signature-bug-on-the-mev-boost-ecosystem-at-the-shapella-fork/1623? I hav… --- ## [The method eth\_callBundle does not exist/is not available](https://collective.flashbots.net/t/the-method-eth-callbundle-does-not-exist-is-not-available/3822)
**Author:** [@zeke](https://collective.flashbots.net/u/zeke)\ **Replies:** 0\ **Last updated:** [September 5, 2024, 1:18am UTC](https://collective.flashbots.net/t/the-method-eth-callbundle-does-not-exist-is-not-available/3822 "2024-09-05T01:18:22Z")
I am trying to implement flashbots when sending transactions and I am getting: the method eth\_callBundle does not exist/is not available. This when I use https://builder0x69.io/ as my relay. When I use https://relay.fla… --- ## [Question: Is it worthwhile to start operating a new relay at this point?](https://collective.flashbots.net/t/question-is-it-worthwhile-to-start-operating-a-new-relay-at-this-point/3807)
**Author:** [@nana](https://collective.flashbots.net/u/nana)\ **Replies:** 3\ **Last updated:** [August 30, 2024, 12:27pm UTC](https://collective.flashbots.net/t/question-is-it-worthwhile-to-start-operating-a-new-relay-at-this-point/3807 "2024-08-30T12:27:02Z")
I’m considering operating a neutral relay, but is it actually worth the effort, or how does the community view this? Flashbots has announced TEE-Boost. There are also discussions about Preconfirmation and PROF. Regardin… --- ## [Vulnerability in eth\_callBundle and eth\_sendBundle](https://collective.flashbots.net/t/vulnerability-in-eth-callbundle-and-eth-sendbundle/3803)
**Author:** [@aman9723](https://collective.flashbots.net/u/aman9723)\ **Replies:** 0\ **Last updated:** [August 27, 2024, 4:41pm UTC](https://collective.flashbots.net/t/vulnerability-in-eth-callbundle-and-eth-sendbundle/3803 "2024-08-27T16:41:55Z")
Is there any vulnerability in the eth\_callBundle and eth\_sendBundle rpc calls? In anyway my bundle transactions could be hacked or leaked when sending via them? --- ## [What is validation node within the Relay?](https://collective.flashbots.net/t/what-is-validation-node-within-the-relay/3786)
**Author:** [@Kosala](https://collective.flashbots.net/u/Kosala)\ **Replies:** 2\ **Last updated:** [August 26, 2024, 2:26pm UTC](https://collective.flashbots.net/t/what-is-validation-node-within-the-relay/3786 "2024-08-26T14:26:11Z")
I am trying to deploy and run mev-boost-relay. In mev-boost flashbots relay diagram on (Notion – The all-in-one workspace for your notes, tasks, wikis, and databases.), I can see validation nodes. What are validation n… --- ## [Troubleshooting bundle submission](https://collective.flashbots.net/t/troubleshooting-bundle-submission/3611)
**Author:** [@daniel.las](https://collective.flashbots.net/u/daniel.las)\ **Replies:** 0\ **Last updated:** [June 28, 2024, 6:42am UTC](https://collective.flashbots.net/t/troubleshooting-bundle-submission/3611 "2024-06-28T06:42:10Z")
Hi, I tried to send the bundle couple of days ago via https://relay.flashbots.net but failed to do so despite of many attempts. The bundle consisted of 4 transactions with total gas 5254130. The maxPriorityFeePerGas wa… --- ## [Hacking on Relayscan Bid Archive for half an hour](https://collective.flashbots.net/t/hacking-on-relayscan-bid-archive-for-half-an-hour/3537)
**Author:** [@guayabyte](https://collective.flashbots.net/u/guayabyte)\ **Replies:** 0\ **Last updated:** [June 12, 2024, 8:14pm UTC](https://collective.flashbots.net/t/hacking-on-relayscan-bid-archive-for-half-an-hour/3537 "2024-06-12T20:14:07Z")
With @metachris --- ## [Is the Flashbots "builder" repository used for ETH staking relayers or something else?](https://collective.flashbots.net/t/is-the-flashbots-builder-repository-used-for-eth-staking-relayers-or-something-else/3372)
**Author:** [@adamhurwitz.eth](https://collective.flashbots.net/u/adamhurwitz.eth)\ **Replies:** 0\ **Last updated:** [April 30, 2024, 12:28am UTC](https://collective.flashbots.net/t/is-the-flashbots-builder-repository-used-for-eth-staking-relayers-or-something-else/3372 "2024-04-30T00:28:13Z")
Hi Flashboters, I’m a researcher and nomad looking to learn more about Ethereum by running a validator on testnet. This week I’m starting research on remote self staking (RSS) \[1\] as I wrap up my current project on the S… --- ## [MB-Direct: An idea for MEV-Boost improvement](https://collective.flashbots.net/t/mb-direct-an-idea-for-mev-boost-improvement/3350)
**Author:** [@Quintus](https://collective.flashbots.net/u/Quintus)\ **Replies:** 6\ **Last updated:** [April 25, 2024, 1:23am UTC](https://collective.flashbots.net/t/mb-direct-an-idea-for-mev-boost-improvement/3350 "2024-04-25T01:23:09Z")
This post outlines some changes to how MEV-Boost works that both allows for improvement in the security and efficiency and the system and would serve as a kind out-of-protocol test for ePBS. tl;dr: proposer gets a list … --- ## [Sepolia relay doesnt produce blocks](https://collective.flashbots.net/t/sepolia-relay-doesnt-produce-blocks/3349)
**Author:** [@loban](https://collective.flashbots.net/u/loban)\ **Replies:** 0\ **Last updated:** [April 23, 2024, 4:25pm UTC](https://collective.flashbots.net/t/sepolia-relay-doesnt-produce-blocks/3349 "2024-04-23T16:25:04Z")
Sepolia relay doesnt produce blocks fix pls --- ## [Does Flashbots Relay accept blocks from external builders without a paid plan?](https://collective.flashbots.net/t/does-flashbots-relay-accept-blocks-from-external-builders-without-a-paid-plan/3294)
**Author:** [@Kosala](https://collective.flashbots.net/u/Kosala)\ **Replies:** 0\ **Last updated:** [April 11, 2024, 1:18pm UTC](https://collective.flashbots.net/t/does-flashbots-relay-accept-blocks-from-external-builders-without-a-paid-plan/3294 "2024-04-11T13:18:52Z")
Hi I have noticed, the bloXroute relay has paid plans for external builders to submit blocks. Is this same for the Flashbots Relay? Would the Flashbots Relay accept blocks from external builders without a paid plan? Than… --- ## [Cannot see OFAC filter implemented within the source code](https://collective.flashbots.net/t/cannot-see-ofac-filter-implemented-within-the-source-code/3153)
**Author:** [@Kosala](https://collective.flashbots.net/u/Kosala)\ **Replies:** 0\ **Last updated:** [March 6, 2024, 12:44pm UTC](https://collective.flashbots.net/t/cannot-see-ofac-filter-implemented-within-the-source-code/3153 "2024-03-06T12:44:26Z")
Hi Team, Within the given Relay source code (GitHub - flashbots/mev-boost-relay: MEV-Boost Relay for Ethereum proposer/builder separation (PBS)), I cannot find OFAC filtering implemented. I am planning to deploy a Relay … --- ## [Why boost Relay source code in Github does not support holesky?](https://collective.flashbots.net/t/why-boost-relay-source-code-in-github-does-not-support-holesky/3145)
**Author:** [@Kosala](https://collective.flashbots.net/u/Kosala)\ **Replies:** 0\ **Last updated:** [March 5, 2024, 11:04am UTC](https://collective.flashbots.net/t/why-boost-relay-source-code-in-github-does-not-support-holesky/3145 "2024-03-05T11:04:43Z")
I recently cloned the mev-boost relay (GitHub - flashbots/mev-boost-relay: MEV-Boost Relay for Ethereum proposer/builder separation (PBS)). I tried to deploy a relay using this source code. However, I cannot see this rep… --- ## [Block scoring for mev-boost relays](https://collective.flashbots.net/t/block-scoring-for-mev-boost-relays/202)
**Author:** [@thegostep](https://collective.flashbots.net/u/thegostep)\ **Replies:** 38\ **Last updated:** [February 22, 2024, 8:49am UTC](https://collective.flashbots.net/t/block-scoring-for-mev-boost-relays/202 "2024-02-22T08:49:11Z")
We need to come up with a standard way to score the value of a block under the mev-boost architecture. This standard is a dependency for a multitude of components including relay monitoring, validator accounting, builder… --- ## [How to test validator registrations in a testnet?](https://collective.flashbots.net/t/how-to-test-validator-registrations-in-a-testnet/2864)
**Author:** [@Kosala](https://collective.flashbots.net/u/Kosala)\ **Replies:** 0\ **Last updated:** [January 4, 2024, 4:16pm UTC](https://collective.flashbots.net/t/how-to-test-validator-registrations-in-a-testnet/2864 "2024-01-04T16:16:48Z")
I deployed flashbots relay on my local machine. When I am testing validator registration using curl -X POST localhost:9062/eth/v1/builder/validators -d @testdata/valreg1.json, gives an error - not a known validator. I tr… --- ## [Where do you get a list of builders addresses?](https://collective.flashbots.net/t/where-do-you-get-a-list-of-builders-addresses/443)
**Author:** [@metachris](https://collective.flashbots.net/u/metachris)\ **Replies:** 2\ **Last updated:** [January 4, 2024, 3:58pm UTC](https://collective.flashbots.net/t/where-do-you-get-a-list-of-builders-addresses/443 "2024-01-04T15:58:54Z")
where do you get the list of addresses for MEV boost block builders? --- ## [Error when trying to start the housekeeper within the Relay](https://collective.flashbots.net/t/error-when-trying-to-start-the-housekeeper-within-the-relay/2796)
**Author:** [@Kosala](https://collective.flashbots.net/u/Kosala)\ **Replies:** 4\ **Last updated:** [December 12, 2023, 2:41pm UTC](https://collective.flashbots.net/t/error-when-trying-to-start-the-housekeeper-within-the-relay/2796 "2023-12-12T14:41:40Z")
I need to deploy the flahbots Relay on my local environment. I followed the flashbots Relay Readme file and tried the following command to start the housekeeper of the Relay. $\> go run . housekeeper --network sepolia --… --- ## [Ideas for Incentivizing Relays](https://collective.flashbots.net/t/ideas-for-incentivizing-relays/586)
**Author:** [@dmarz](https://collective.flashbots.net/u/dmarz)\ **Replies:** 13\ **Last updated:** [October 23, 2023, 7:07pm UTC](https://collective.flashbots.net/t/ideas-for-incentivizing-relays/586 "2023-10-23T19:07:41Z")
It’s currently a problem that we do not have more relays, especially from organizations in differing geographies. But as it stands relays are not cheap and there is no incentive to run one unless you’re also a builder. C… --- ## [How to prevent MEV stealing by Proposer?](https://collective.flashbots.net/t/how-to-prevent-mev-stealing-by-proposer/2473)
**Author:** [@ywzx](https://collective.flashbots.net/u/ywzx)\ **Replies:** 2\ **Last updated:** [September 30, 2023, 1:11am UTC](https://collective.flashbots.net/t/how-to-prevent-mev-stealing-by-proposer/2473 "2023-09-30T01:11:19Z")
Regarding the FAQ on preventing MEV by Proposers, I’m having trouble fully understanding the concept and would like to confirm my understanding. What prevents block proposers from stealing MEV from submitted builders’ b… --- ## [Relayer Submission acknowledged but not recieved](https://collective.flashbots.net/t/relayer-submission-acknowledged-but-not-recieved/2249)
**Author:** [@dotokk](https://collective.flashbots.net/u/dotokk)\ **Replies:** 3\ **Last updated:** [August 30, 2023, 8:58am UTC](https://collective.flashbots.net/t/relayer-submission-acknowledged-but-not-recieved/2249 "2023-08-30T08:58:52Z")
I’m trying to send block submissions to the flashbots relay, and I’m getting a 202 response code with a body like {cs:0xc02d2ba000}. My builder is configured to submit 4s into the block every 1s. However, when calling /… --- ## [About relay-url](https://collective.flashbots.net/t/about-relay-url/2236)
**Author:** [@dongri](https://collective.flashbots.net/u/dongri)\ **Replies:** 0\ **Last updated:** [August 19, 2023, 11:57am UTC](https://collective.flashbots.net/t/about-relay-url/2236 "2023-08-19T11:57:25Z")
As write here, all relay-url is 0xXXX@domain.com. Where is the 0xXXX (BLS public key) used here? Do I need to set it up? --- ## [Towards Trustless Optimistic Relaying](https://collective.flashbots.net/t/towards-trustless-optimistic-relaying/1761)
**Author:** [@SFYLL](https://collective.flashbots.net/u/SFYLL)\ **Replies:** 1\ **Last updated:** [May 13, 2023, 10:12am UTC](https://collective.flashbots.net/t/towards-trustless-optimistic-relaying/1761 "2023-05-13T10:12:36Z")
Hey sirs, I think we should get started on the conversation of reducing trust towards relayers. They are low hanging fruits with relatively little overhead that can benefit not only the proposer-builder-relayer trifecta… --- ## [Monitoring Validator\_Registration for Fee Recipients](https://collective.flashbots.net/t/monitoring-validator-registration-for-fee-recipients/1719)
**Author:** [@0xSmoothly](https://collective.flashbots.net/u/0xSmoothly)\ **Replies:** 1\ **Last updated:** [May 9, 2023, 1:34pm UTC](https://collective.flashbots.net/t/monitoring-validator-registration-for-fee-recipients/1719 "2023-05-09T13:34:05Z")
Hey All! I’m Kody, and we’re building Smoothly, an open source tool for solo stakers to use to pool together tips and MEV from block proposals. We’ve been live on Goerli for a few months now fixing bugs and refining our … --- ## [Bookmarks relevant for relays](https://collective.flashbots.net/t/bookmarks-relevant-for-relays/401)
**Author:** [@guayabyte](https://collective.flashbots.net/u/guayabyte)\ **Replies:** 12\ **Last updated:** [April 12, 2023, 11:16am UTC](https://collective.flashbots.net/t/bookmarks-relevant-for-relays/401 "2023-04-12T11:16:52Z")
Share your links here :chains: . --- ## [Optimistic relaying on ultra sound relay](https://collective.flashbots.net/t/optimistic-relaying-on-ultra-sound-relay/1486)
**Author:** [@mikeneuder.eth](https://collective.flashbots.net/u/mikeneuder.eth)\ **Replies:** 0\ **Last updated:** [March 20, 2023, 3:24pm UTC](https://collective.flashbots.net/t/optimistic-relaying-on-ultra-sound-relay/1486 "2023-03-20T15:24:05Z")
hello Flashbots community! on March 17, 2023 at 12pm UTC, the ultra sound relay launched optimistic relaying. after monitoring the launch and collecting data this weekend, we are happy to share “An optimistic weekend” –… --- ## [The Flashbots Builder is now sending to external relays](https://collective.flashbots.net/t/the-flashbots-builder-is-now-sending-to-external-relays/898)
**Author:** [@angelfish](https://collective.flashbots.net/u/angelfish)\ **Replies:** 1\ **Last updated:** [March 1, 2023, 5:08pm UTC](https://collective.flashbots.net/t/the-flashbots-builder-is-now-sending-to-external-relays/898 "2023-03-01T17:08:42Z")
To foster a more competitive and healthy relay ecosystem, the Flashbots Builder is now sending blocks to Agnostic Relay by GnosisDAO and Ultrasound Relay by Ultrasound Money. We have also added this feature to submit bl… --- ## [Getting cors error in sendRawTransaction function from reactjs localhost](https://collective.flashbots.net/t/getting-cors-error-in-sendrawtransaction-function-from-reactjs-localhost/1347)
**Author:** [@jatinder](https://collective.flashbots.net/u/jatinder)\ **Replies:** 0\ **Last updated:** [February 27, 2023, 11:47am UTC](https://collective.flashbots.net/t/getting-cors-error-in-sendrawtransaction-function-from-reactjs-localhost/1347 "2023-02-27T11:47:20Z")
Hello everyone ,I need some help for transfer ethers using flashbots sendRawTransction on testnet from reactjs localhost. I am getting the cors error in sendRawTransaction request , can anyone help me out. Access to fe… [Next page](https://collective.flashbots.net/c/relays/15.md?page=1)