Harmonic has opened its Searcher Network to the public in beta. The network lets vetted trading firms pay to place a trade directly after a user's transaction on Solana, but never ahead of it. In its announcement on 5 November 2026, Harmonic said the network had generated "over 25,000 SOL for validators and stakers" since early August, and that it now opens with "backrunning only, no toxic MEV, and KYC/KYB-vetted searchers monitored by our compliance system."
Harmonic is the block-building marketplace run by Temporal, the Solana research and infrastructure firm that also operates HumidiFi and the Nozomi transaction-sending service. The 25,000 SOL figure is Harmonic's own and has not been independently audited.
What the Harmonic Searcher Network does
The Harmonic Searcher Network is an auction for backruns. A backrun is a trade placed immediately after someone else's transaction to capture the price move it causes, such as an arbitrage that rebalances two pools after a large swap. Searchers, the trading firms that hunt for these openings, bid for the right to place them, and the winning bids go to the validator producing the block.
MEV (maximal extractable value) is the profit available from choosing the order of transactions in a block. The "toxic" kind Harmonic says it excludes includes the sandwich, where a searcher trades just before a user to push the price against them and then sells just after. Harmonic's product page puts the rule plainly: "No searcher trades ahead of a user's transaction."
Harmonic's longer announcement article, excerpted on X, says the 25,000 SOL accrued "since the start of our private alpha in early August". The public beta widens that alpha to more searchers.
How Harmonic's KYC-vetted backrun auction works
According to the Harmonic Searcher Network page, a transaction that reaches Harmonic's transaction-processing unit is shown only to vetted searchers. "Every searcher passes KYC/KYB and AML checks before it sees a single transaction," the page says. KYC and KYB are identity checks on individuals and businesses; AML is anti-money-laundering screening.
Each searcher's backrun is recorded on a compliance server before it executes. Searchers then bid in what Harmonic calls "a frequent batch auction", which gathers bids over a short window and settles them together rather than rewarding whoever is fastest. "There is no fast lane," the page says. The winning bundle lands with the user's transaction first and the searcher's trade directly behind it in the same block.
Harmonic says it monitors trades in real time and that "Blockline, our contracted third-party auditor, reviews any contested trade." On revenue, the page says competition pushes most of a searcher's profit into the bid paid to the validator, and "any remaining searcher PnL is shared between the searcher and the validator."
Validators choose which searcher strategies they allow in their blocks, according to the product page: arbitrage, sniping, copy trading, or any combination. Harmonic's FAQ says tips on Harmonic are paid as ordinary compute-unit priority fees rather than transfers to a tip account, so validators receive the full tip.
Who is behind Harmonic and Temporal
Harmonic raised a $6 million seed round led by Paradigm in November 2025, The Block reported. The outlet said the team of about ten is based in New York and that co-founder Jakob Povsic also co-founded Temporal. Harmonic's core product lets validators take blocks from several competing builders each slot, and Povsic told The Block that "a validator might prefer blocks without toxic MEV." Temporal presented the marketplace at Breakpoint 2025.
On 27 October 2026, Temporal named ex-Galaxy DeFi head Michael Marcantonio as CEO. Its press release said Harmonic's block builder "serves validators representing roughly 30% of Solana's total stake." That figure covers the block builder; the Searcher Network is a separate opt-in on top of it.
Harmonic and Jito: two routes for Solana MEV
Harmonic has built its searcher interface so that firms already bidding through Jito JTO$0.343-3.8% can switch with little work. Harmonic's FAQ says its gRPC API is "backwards-compatible with Jito's searcher protos", so existing Jito client code needs only a new endpoint and imports. Users can protect a transaction from frontrunning by including a dontfront or jitodontfront account, and Harmonic honours both.
What Harmonic adds is a gate on who may bid: only identified firms that accept backrun-only rules and a pilot period. Jito is pursuing its own block-building changes through BAM, and on 2 November 2026 named Triton One, Bitwise and SOL Strategies as its first third-party BAM node operators.
For stakers, the point is the revenue line. Validators that share block revenue with delegators pass on part of what searchers pay, so a second, compliance-screened source of bids adds to what those validators can distribute. For a sense of the existing market, tips paid through Jito came to about 148,000 SOL between 9 August and 5 November 2026, according to our network fees data. The two figures are not like for like: Jito's is tips paid across the network, while Harmonic's 25,000 SOL is its own count of what its searchers generated for participating validators and stakers.
How to join the Harmonic Searcher Network beta
Searchers apply through Harmonic's searcher application. New searchers then run a "7 to 14 day pilot on sandboxed validators before full admission", according to the product page. Validators apply through the Run Harmonic form and pick their permitted strategies in their validator configuration.
Harmonic's announcement article says "never-before-seen and innovative searcher APIs" are in the works, with rollout "expected in the coming weeks". The details to watch are how many validators and how much stake opt in during the beta, whether Harmonic publishes the searcher-validator profit split, and whether Blockline's reviews are made public.
