Relayers

Relayers evaluated across what the relayer is authorised to do and whether you can keep the address; exactly-once execution and stuck-queue recovery; what a stolen API credential can do before anyone notices; and where the gas float sits and how you get it back.

7providers tracked

7ranked (methodology v2026.10.18)

3 November 2026Ranking snapshot

11 August 2026oldest read · due 25 Sep

Independent. Evidence-based.We rank with a published method and sourced evidence. No one can pay to rank.How it works

7 providers match your requirements

Out of 7 ranked providers. 0 excluded.

What this ranks

Ranked here: transaction relayers that hold a key and front gas so a backend can send transactions as itself.Not ranked here: anything that does not send transactions for a backend, holding the key and fronting the gas on its behalf.7 of the 7 assessed are ranked.Requirements narrow the list; they never change a published ChainChoice Score. How the ranking works

Coinbase CDP Server Wallets (API-key wallets)

How Coinbase CDP Server Wallets (API-key wallets) was chosen

Leads this ranking on What a stolen API credential can do before anyone notices

A backend API

ChainChoice Score81 out of 100

Evidence

High

4/4 criteria scored, with 4 dated sources quoted.

What a stolen API credential can do before anyone noticesWhat the relayer is authorised to do, and whether you can keep the addressWhere the gas float sits and how you get it back

Why it leads

Coinbase CDP Server Wallets (API-key wallets) is 3 points ahead of Privy server wallets, mainly because it scores higher on its credential blast radius and its gas float custody.
Best in this ranking on credential blast radius (10/10; next 9/10)
Ahead of Privy server wallets on credential blast radius (+1.4 points) and gas float custody (+1.2 points)

Tradeoff

Relayer authority and key custody: 1 point below the best in this ranking

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#ProviderPriceCompare

A REST/SDK service

78 out of 100

An AGPL-licensed Rust service a backend team...

73 out of 100

Same score, not joint · ordered by weighted total (45.50 against 45.40)

A hosted relayer

73 out of 100

Circle fronts network fees

70 out of 100

A custodial server-side signer

69 out of 100

A hosted meta-transaction relay

59 out of 100

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See key differences in features, fees, security and more.

Relayer authority and key custody

What the relayer is authorised to do, and whether you can keep the address

32% of the published criteria weight. Scored 0–10 from the published evidence; the order below is by this criterion, then the published ranking.

Provider	Relayer authority and key custody (0–10)	ChainChoice Score
OpenZeppelin Relayer	10	73
Coinbase CDP Server Wallets (API-key wallets)	9	81
Privy server wallets	9	78
Sequence Transactions API (Relayer)	9	73
Openfort backend wallets	9	69
Gelato Relay	7	59
Circle Gas Station	6	70

Gas float custody

Where the gas float sits and how you get it back

20% of the published criteria weight. Scored 0–10 from the published evidence; the order below is by this criterion, then the published ranking.

Provider	Gas float custody (0–10)	ChainChoice Score
OpenZeppelin Relayer	9	73
Coinbase CDP Server Wallets (API-key wallets)	8	81
Circle Gas Station	8	70
Privy server wallets	7	78
Sequence Transactions API (Relayer)	7	73
Openfort backend wallets	7	69
Gelato Relay	2	59

Exactly once execution

Exactly-once execution and stuck-queue recovery

26% of the published criteria weight. Scored 0–10 from the published evidence; the order below is by this criterion, then the published ranking.

Provider	Exactly once execution (0–10)	ChainChoice Score
Coinbase CDP Server Wallets (API-key wallets)	7	81
Privy server wallets	7	78
Circle Gas Station	7	70
OpenZeppelin Relayer	6	73
Sequence Transactions API (Relayer)	6	73
Openfort backend wallets	4	69
Gelato Relay	4	59

Credential blast radius

What a stolen API credential can do before anyone notices

22% of the published criteria weight. Scored 0–10 from the published evidence; the order below is by this criterion, then the published ranking.

Provider	Credential blast radius (0–10)	ChainChoice Score
Coinbase CDP Server Wallets (API-key wallets)	10	81
Privy server wallets	9	78
Sequence Transactions API (Relayer)	6	73
Circle Gas Station	6	70
Openfort backend wallets	6	69
Gelato Relay	6	59
OpenZeppelin Relayer	3	73

All 4 published criteria

Every ranked row’s score on each criterion, in the published order. Choose a column to order by it.

	Provider					ChainChoice Score
1	Coinbase CDP Server Wallets (API-key wallets)	9	7	10	8	81
2	Privy server wallets	9	7	9	7	78
3	OpenZeppelin Relayer	10	6	3	9	73
4	Sequence Transactions API (Relayer)	9	6	6	7	73
5	Circle Gas Station	6	7	6	8	70
6	Openfort backend wallets	9	4	6	7	69
7	Gelato Relay	7	4	6	2	59

How this ranking works

How firm the #1 is, the per-criterion arithmetic behind each score, who pays ChainChoice, and which relayers were assessed and left out.

FirmThis verdict holds under every one-point re-read

See the arithmetic

Every published criterion was moved up and down by one point and the ranking re-run. The same product came first each time. The published rankings file

Why this score4 published criteria · leads 2 of 4

Published criterionWtScore, and the best hereGap out of 10Pts

What the relayer is authorised to do, and whether you can keep the address7.7−199.2

Exactly-once execution and stuck-queue recovery6.2·75.8

What a stolen API credential can do before anyone notices5.3·107.0

Where the gas float sits and how you get it back4.8−185.1

Σ methodology points27.2/32

Each bar is the score on that criterion’s own 0–10 scale, never rescaled to the pool. The dark line is the best any product here reached on that axis. Wt is the most the criterion can add to the 86-point weighted total. Pts is weight × score × 32; the sum is the methodology score, and each weighted point behind the leader costs 2.6 on the displayed score. how these are weighted

Why it ranks first

Why Coinbase CDP Server Wallets (API-key wallets) leads this category right now

A backend API that creates EOAs whose private keys are generated inside Coinbase's AWS Nitro Enclave TEE, then signs and broadcasts transactions from them on seven EVM mainnets and Solana, with import and export of the raw private key both exposed as REST endpoints. Strongest on what a stolen API credential can do before anyone notices (10/10): The send-transaction policy takes five server-side criteria (value cap, destination allowlist, network, calldata function and arguments, and a USD net-change cap) and rejects by default. Every send also needs a separate X-Wallet-Auth signature, so a stolen API key alone cannot move funds. Weakest on exactly-once execution and stuck-queue recovery (7/10): Wallet webhooks publish a replacement lifecycle in which the original transaction "will never land onchain", and flag sends pending over 30 seconds with their gas values. The docs sitemap lists no wallet cancel or nonce-reset endpoint; the buyer builds any replacement and must pin the nonce. Published price: "CDP non-custodial wallets use a pay-as-you-go model with no contracts or minimum commitments." / "Wallet usage is billed in wallet operations.

Best for

What a stolen API credential can do before anyone notices — 10/10

Main tradeoff

CDP does publish replacement semantics — a replaced original "will never land onchain" and fires a `failed` event — but it never uses the word nonce, and there is no cancel or nonce-reset endpoint anywhere in the v2 API. After 30 seconds it hands your backend the stuck transaction's gas parameters and expects you to build the replacement yourself. The X-Idempotency-Key that would protect you cannot be reused: the API "Returns an error if the same key is used with different request parameters", so a higher-gas payload needs a NEW key — and if you then omit the optional nonce field, "the API will assign a nonce to the transaction based on the current state of the account." A fresh nonce makes it a second transaction, not a replacement, and both can land. Pin the nonce yourself or the same intent can be mined twice.

Verify before signup

"CDP non-custodial wallets use a pay-as-you-go model with no contracts or minimum commitments." / "Wallet usage is billed in wallet operations. A wallet operation is consumed by write actions such as wallet creation, message signing, transaction signing, transaction broadcasting, and policy evaluation." / "Read operations are not billed." / table rows: "Send a transaction (sign + broadcast) | 2" and "Policy evaluation (API key auth workflows) | 1" / "Each wallet operation costs $0.005." / "The first 5,000 wallet operations per month are free." / "Usage is billed at the beginning of each calendar month for the previous month." (Coinbase Developer Platform wallet pricing page, https://docs.cdp.coinbase.com/wallets/pricing, fetched 28 September 2026; the per-operation price, free tier and send/policy rows match the 11 August 2026 read, and the same table also lists "Create EIP-7702 delegation | 2"). Recorded for the record only — this page publishes no cost ranking for relayers; per-transaction price is scored on account_abstraction_infra and cost-per-call on rpc_nodes, and no criterion here touches this figure. The unit is a "wallet operation", not a transaction: a relayed send consumes 2, and 3 when an API-key policy is evaluated. The gas itself is not priced here — on the EOA path it is paid from the buyer's own account balance, so no markup or premium is published for it.

Recommendation summary

What should decide this category

Does the vendor's address become msg.sender inside your contracts, or does it only fund a call your end user signed?

Can you keep the address — import a key, export the one they generated, or point the service at a signer you control?

If a repriced transaction is resubmitted, does it reuse the original nonce, so the intent executes at most once?

What can a stolen API token send before anyone notices — and can that same token delete the limits meant to bound it?

Quick picks

Strong options in this category

Start with the lead choice first, then use the shortlist only if you still need a challenger or stronger fit for a specific setup.

Best overall

Coinbase CDP Server Wallets (API-key wallets)

Best for: What a stolen API credential can do before anyone notices — 10/10

What the relayer is authorised to do, and whether you can keep the address · weight 32%9/10Exactly-once execution and stuck-queue recovery · weight 26%7/10What a stolen API credential can do before anyone notices · weight 22%10/10Where the gas float sits and how you get it back · weight 20%8/10

Quick pick

Privy server wallets

A REST/SDK service that generates or imports secp256k1 and Ed25519 keys into a TEE, holds them under an app-held P-256 authorization key (optionally an m-of-n key quorum), and signs and broadcasts transactions from those addresses on request from the buyer's backend — with gas paid by default from the wallet's own native balance, or optionally sponsored from a prepaid app-level gas-credits balance, or collected on-chain from the wallet's stablecoin balance by an ERC-20 paymaster in 'User pays' mode. Strongest on what the relayer is authorised to do, and whether you can keep the address (9/10): The server wallet's own address is msg.sender. Privy documents importing private keys into its API and exporting server-side wallets through its server SDKs or REST API; export needs a wallet owner and can be disabled by a deny policy. No buyer-run external signer is offered. Weakest on exactly-once execution and stuck-queue recovery (7/10): Privy states that a replacement sent with the same nonce as a pending transaction carries no risk of both executing, and idempotency keys block duplicate requests for 24 hours. It does not retry or reprice for the buyer, and its API specification has no cancel, nonce-sync or gap-advance endpoint. Published price: NOT USED IN ANY SCORE ON THIS PAGE (cost is scored on account_abstraction_infra and rpc_nodes); recorded because the schema requires it.

Best for: What the relayer is authorised to do, and whether you can keep the address — 9/10

What the relayer is authorised to do, and whether you can keep the address · weight 32%9/10Exactly-once execution and stuck-queue recovery · weight 26%7/10What a stolen API credential can do before anyone notices · weight 22%9/10Where the gas float sits and how you get it back · weight 20%7/10

Quick pick

OpenZeppelin Relayer

An AGPL-licensed Rust service a backend team runs itself to submit transactions from its own EOA on EVM, Solana and Stellar networks, where the signing key stays in the buyer's own keystore file, HashiCorp Vault, AWS KMS, Google Cloud KMS, Turnkey or Coinbase CDP account rather than in a vendor's vault. Strongest on what the relayer is authorised to do, and whether you can keep the address (10/10): The relayer's EOA is msg.sender, but its key sits in a signer backend the buyer controls: a local keystore, HashiCorp Vault, Vault Transit, Turnkey, Google Cloud KMS, AWS KMS or Coinbase CDP. The API also accepts a plain private key for import, so the address survives a change of operator. Weakest on what a stolen API credential can do before anyone notices (3/10): On EVM the policy object carries two server-side limits, a receiver allowlist and a gas-price cap, but the single bearer API key that sends transactions can also rewrite that policy through the relayer update endpoint. The schema has no value cap, selector restriction, spend ceiling or user-signature requirement. Published price: No price of any kind is published for OpenZeppelin Relayer. https://www.openzeppelin.com/pricing returns HTTP 404 (re-checked 2026-09-28).

Best for: What the relayer is authorised to do, and whether you can keep the address — 10/10

What the relayer is authorised to do, and whether you can keep the address · weight 32%10/10Exactly-once execution and stuck-queue recovery · weight 26%6/10What a stolen API credential can do before anyone notices · weight 22%3/10Where the gas float sits and how you get it back · weight 20%9/10

Quick pick

Same score, not joint · ordered by weighted total (45.50 against 45.40)

Sequence Transactions API (Relayer)

A hosted relayer that accepts a signed Sequence smart-contract-wallet transaction bundle from a backend, fronts the network gas either from a Builder-funded sponsorship balance or from an ERC-20 fee transaction included inside the bundle, and submits it on chain-specific relayer hosts (52 published in the vendor's OpenAPI servers block, of which 21 mainnet hosts answered live on 2026-08-11). Strongest on what the relayer is authorised to do, and whether you can keep the address (9/10): The backend acts through a Sequence smart-contract wallet built from a key the buyer supplies: a local private key, AWS KMS or GCP KMS. The quickstart states that msg.sender is the Sequence wallet address rather than the EOA, so contracts grant their role to that wallet. Weakest on exactly-once execution and stuck-queue recovery (6/10): The transactions API asserts automatic nonce management and resubmits after 3 blocks, with no repricing ceiling. Signed wallet nonces stop a resubmitted bundle from running twice, but no at-most-once guarantee is stated, and the transactions overview names no cancel or nonce-reset method. Published price: No rate for relayed transactions or gas is published on any page that could be fetched.

Best for: What the relayer is authorised to do, and whether you can keep the address — 9/10

What the relayer is authorised to do, and whether you can keep the address · weight 32%9/10Exactly-once execution and stuck-queue recovery · weight 26%6/10What a stolen API credential can do before anyone notices · weight 22%6/10Where the gas float sits and how you get it back · weight 20%7/10

Considered and not ranked

None left out by name

We assessed 7 products here and rank all 7. No product has been turned away by name; when one is, its name and the reason appear here. Evidence last read 11 August 2026.

What this ranking does not assess

Exit failure: you cannot get out at par, on time, or with what is yours.

These can still cost you money here; the ranking does not measure them, so a high place says nothing about them. Which criterion scores each family, and why the others do not apply, is in /data/risk-coverage.json.

How this ranking is built

Reviewed on what the relayer is authorised to do, and whether you can keep the address, exactly-once execution and stuck-queue recovery, what a stolen API credential can do before anyone notices, and where the gas float sits and how you get it back.

Data checked Oct 2026 · Independent rankings · We show our work

Reviewed 11 August 2026

Re-read in progress

Overdue; re-read by 10 November 2026.

Published 11 August 2026Methodology v2026.10.18

How this page is reviewed

Reviewed means every product ranked on this page was read against its sources on or after that date; every ranked category is re-read at least every 45 days. Models research, extract and parse. A deterministic engine ranks. Every quote passes an adversarial refute pass.

Accountable for this review: Mathias Siemonsmeier, Founder.

How we review · Review calendar · Corrections log · How we make money

Direct answer

What is the best relayer service in 2026?

Coinbase CDP Server Wallets (API-key wallets) ranks #1 overall for relayers on ChainChoice. A backend API that creates EOAs whose private keys are generated inside Coinbase's AWS Nitro Enclave TEE, then signs and broadcasts transactions from them on seven EVM mainnets and Solana, with import and export of the raw private key both exposed as REST endpoints. It holds that rank under an affiliate-blind methodology scored across 4 published, weighted criteria — the code that ranks providers physically cannot read affiliate payouts (CI-enforced), so a payout can't move a rank. The verdict re-computes on every fee change, incident, or regulatory action; the full reasoning and the audit receipt are under Methodology.

How you can lose money here, and what the ranking scores

Liveness failure: the operator stops, censors you or loses data.
Scored by Exactly-once execution and stuck-queue recovery · 26% (Coinbase CDP Server Wallets (API-key wallets) 7/10, Privy server wallets 7/10, OpenZeppelin Relayer 6/10)
Custody failure: whoever holds the assets loses or withholds them.
Scored by What the relayer is authorised to do, and whether you can keep the address · 32% (Coinbase CDP Server Wallets (API-key wallets) 9/10, Privy server wallets 9/10, OpenZeppelin Relayer 10/10)
Scored by What a stolen API credential can do before anyone notices · 22% (Coinbase CDP Server Wallets (API-key wallets) 10/10, Privy server wallets 9/10, OpenZeppelin Relayer 3/10)
Scored by Where the gas float sits and how you get it back · 20% (Coinbase CDP Server Wallets (API-key wallets) 8/10, Privy server wallets 7/10, OpenZeppelin Relayer 9/10)

Not assessed by this ranking: Exit failure. A high place says nothing about these; the Methodology tab says what each means.

FAQs

5 questions readers ask before choosing relayers.

Frequently asked

Questions people ask before choosing relayers

What can a stolen API credential actually send?

On OpenZeppelin Relayer the credential that sends your transactions can also delete the limits that bound it. RelayerEvmPolicy carries exactly seven fields and, because additionalProperties is false, the absences are provable: no per-transaction value cap, no function-selector restriction, no daily or monthly ceiling. Only two fields bound a stolen token at all — whitelist_receivers and gas_price_cap — and PATCH /api/v1/relayers/{relayer_id} accepts the policy object, so the same unscoped bearer token can rewrite both, repoint custom_rpc_urls, execute plugins and call POST /sign. It is an operator-error guard, not a security boundary.

If the relayer retries, can the same transaction execute twice?

Not one relayer in this pool can tell you whether a retry charges your user twice. Every provider scored here lands between 4 and 7 out of 10 on exactly-once execution, and the reason is uniform: they publish the words "nonce management, gas estimation and resubmission" and stop. Across all 38 live Gelato relay and Gas Tank pages the strings retry, resubmit, reprice, idempotent, at-most-once, duplicate, cancel, stuck and escalate occur ZERO times, and the two knobs its older docs advertised now survive only on pages Gelato itself files under "Legacy Documentation". Coinbase does state that a replaced transaction "will never land onchain" — and never once uses the word nonce.

Can I get the gas I deposit back out?

Ask before you fund, because one provider's answer is no and it is not written where you would look. Money goes into Gelato's Gas Tank and the only statement in the whole of its documentation about getting it out is "It's important to remember that the current Gas Tank system does not support withdrawals after depositing funds." — published on a VRF integration guide, not on any relay page, and not on the Gas Tank page that the relay setup guide itself links to, which walks through depositing in five numbered steps and never mentions withdrawal. The float is also single-chain and single-token: "Since Gas Tank is deployed on Polygon, you can deposit USDC in one step", funding all 42 mainnets from one bridged balance. Elsewhere the mechanics differ enough to matter — a prefunded balance in a vendor-controlled address, a deposit contract you can withdraw from, a fee taken on-chain out of the transaction itself, or a postpaid invoice — and where a vendor is silent about what happens to a residual balance on shutdown, that silence is recorded here as the finding rather than smoothed over.

Why is there no price ranking on this page?

Because it is already published twice, and printing it a third time would make this site contradict itself. Price per user operation and the markup a vendor adds to the gas it fronts are scored on Account Abstraction Infra; cost per call is scored on RPC & Node Services. Several vendors here sell across those pages on one meter — one bills relay, bundling and node access from a single compute-unit balance whose plan table is already quoted verbatim on the rollup-as-a-service page, and another is already ranked as having the lowest published gas surcharge in its pool, on a different product line from the one ranked here. Publishing a second number for the same company under a new heading would be a contradiction a reader would find before we did. So this page ranks trust and correctness instead: authority over the address, retry semantics, credential blast radius, and float custody. Every provider's published pricing is still recorded verbatim in its entry — it is simply not permitted to move the ranking.

Does the advertised chain list mean the relayer actually works there?

Not reliably. Seven mainnet chains one provider advertises do not resolve at all: Sequence's own OpenAPI servers block publishes relayer hosts for polygon-zkevm, blast, sei, xai, incentiv, laos and rootnet that return NXDOMAIN, and 18 of the 57 published hosts overall have no DNS record (checked 2026-08-11). Nothing on any Sequence page says whether those are deprecated, pre-announced or an oversight, so the published grid cannot be read as a capability list — verify your chain answers before you build on it. A related trap runs the other way: enabling gas sponsorship on Circle requires an ERC-4337 smart contract account, and Circle's own queue table gives that wallet a limit of 1 transaction on Ethereum, Polygon and Avalanche against 32, 16 and 32 for a plain EOA, so the buyer who turns sponsorship on to improve the experience drops to one in-flight transaction at a time on three of the largest chains.

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Best picks

Best relayers in 2026

This page deliberately publishes no cost ranking, and that is the first thing to know about it. Price per transaction and the markup on sponsored gas are already scored on Account Abstraction Infra, and cost per call on RPC & Node Services, so ranking them again here would print the same numbers under a different heading — and in one case contradict them. What is left is the part nobody else asks, because a relayer inverts the usual arrangement: everywhere else on this site the user signs and the vendor forwards, but a relayer holds a key and transacts as your backend, which means its address ends up holding a privileged role inside your own contracts. So start with what that address is allowed to do and whether you can keep it, because an address is wired into contracts as a role grant and a key you cannot export turns leaving into an on-chain re-permissioning exercise. Then read the retry semantics, where this pool is uniformly weak: nobody here scores above 7, because vendors publish the words "nonce management, gas estimation and resubmission" and stop short of saying whether a repriced transaction reuses its nonce. Then check what a leaked API token can actually send, and last, whether the gas you deposit can ever come back out.

Best overall

Coinbase CDP Server Wallets (API-key wallets)

Data checked Oct 2026

Best for: What a stolen API credential can do before anyone notices — 10/10

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Written and reviewed by Mathias Siemonsmeier Founder

Not financial advice · For informational purposes only · Always do your own research

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7 providers match your requirements

Why it leads

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