An exchange is a regulated machine — built to be owned, not rented
Whether you start from a blank sheet or a white-label box, the hard part is the same everywhere: the regulated plumbing around the order book. This workspace compiles what we learned scoping and building exchanges across markets — use it before any vendor shows you a slide deck. Sections 01–07 are the buyer’s view: routes, vendors, licensing, corridors. Sections 08–11 are ours to defend — the engagements behind those numbers, the architecture we assemble, a written boundary between what we have run in production and what gets built new, and the operational answer on custody security, incident response and proof of reserves.
3 routesvendor core · composable · fully custom
8 stepsin one order’s regulated round trip
22 regimeson the global licensing map
9 engagementsbehind every number here (section 08)
Three expensive surprises
How to use this workspace
Surprise 01
The white-label ceiling
A vendor box gets you an order book fast — and stops there. Local payment rails, reporting formats, your own roadmap and your own token listings live outside the box. Teams discover this after signing, not before.
Surprise 02
The market layer nobody quotes
Per-transfer reporting, local KYC stacks, payment-rail limits — and in some markets per-trade tax withholding. The mechanics that make an exchange legal in its market exist in no off-the-shelf product. Someone builds them, every time.
Surprise 03
Custody is where exchanges bleed
The largest exchange security losses of recent years were custody-operations failures, not matching-engine failures. Cold-storage segregation, proof-of-reserves and incident playbooks belong in the design — not the post-mortem. Section 10 is the rest of this answer.
The takeaway
Every bidder will sell you their default. This workspace exists so you can walk into that conversation knowing the routes, the vendors, the licensing map and the honest corridors — ask any bidder to show you the path of one dollar through their platform.
10 minutes
Self-serve
Run the route finder — five answers, multi-select what will trade, get a route and corridor.
Drag the anatomy slider — see the 8 steps of one order’s round trip and what a box really covers.
Skim the vendor landscape and the licensing map for your market.
Then
With us
Bring your vendor shortlist — we map it module-by-module: covered / partial / missing.
Discovery turns the corridor into a phased plan with hour ranges and written assumptions.
Gates at every phase — you can stop at any of them.
Compiled from our exchange engagements and estimation library across markets. Vendor and regulatory facts current to mid-2026.
03 · Route finder · Interactive — five answers
Your route, phase one and a corridor
No forms, no email gate. Multi-select what will trade — the finder maps your answers onto the three routes we actually deliver, and says honestly when the answer is “decide in discovery”.
Where are you today?
Your starting point — it changes the route more than anything else.
Where will you be licensed / serve users first?
Pick the closest — the licensing map (section 07) has the full detail per regime.
What will trade? MULTI-SELECT
Add everything on the roadmap — day-one scope vs later phases is exactly what discovery sequences.
How do you feel about renting the core?
In business terms — the engine, order books and admin can be rented from a vendor or owned as your code.
What does the first milestone look like?
Not a commitment — the size of the first bet.
Corridors are indicative bands from module-level estimations of comparable builds; not a quote. The finder’s logic is the same one our architects argue about in discovery — just faster.
05 · Anatomy of one order · The section other bidders will not show you
One order, round trip — eight steps, every market
Money in, buy, sell, money out. Drag the amount, switch the market profile, then flip the white-label toggle and see which steps a vendor box actually covers — and which ones are your build list.
$10,000
Generic market
EU · MiCA
India · FIU
Dubai · VARA
Hong Kong · SFC
Our build — every step covered. Flip to see a typical white-label, out of the box.
How to read it
Every step is something the exchange operator must build, integrate or answer for. The steps a vendor skips in their demo are the ones you will be building — usually under deadline, after signing.
06 · Vendor landscape · 2026
The stack you can rent — and what it honestly covers
The market is real and often good. The mistake is not renting — it is not knowing where the box ends. Facts below are current to mid-2026; published pricing only.
Cross-cutting: on every core, the engine and order books remain the vendor’s; jurisdiction mechanics are in no box. First-year white-label TCO seen across deals: $50–200K.
Vendor
Out of the box
Watch-out
Published pricing
Fireblocks
MPC wallet infrastructure + transfer network; 550M+ wallets served
Enterprise quotes; budget a six-figure annual line at scale
not published
BitGo
Qualified custodian, multi-sig + MPC, wallet-as-a-service; OCC trust charter
Custody vs wallet-tech product lines differ in regulatory cover — pick deliberately
not published
Copper
MPC custody + ClearLoop off-exchange settlement
MiCA authorization was still pending as of mid-2026
not published
Cobo
Custody + wallet-as-a-service; HK TCSP, MAS in-principle
APAC-centric licensing footprint
not published
Utila
Institutional MPC wallet ops incl. DeFi access
Younger vendor, shorter track record
not published
Reference OPEX from deal research: MPC custody $50–250K/yr + $10–50K setup. Custody choice shapes the licence application — decide them together.
Vendor
Out of the box
Watch-out
Published pricing
Sumsub
IDV, liveness, KYB, AML screening, Travel Rule in one platform
Local ID stacks (e.g. national eKYC registries) are not native — pair locally
from $1.35/check, $149/mo min
Jumio
Enterprise IDV, broad document/biometric coverage
Sales-led, quote-based
not published
Onfido (Entrust)
IDV + biometrics inside the Entrust portfolio
Post-acquisition packaging is Entrust-driven — re-verify SLAs
End-to-end Travel Rule SaaS aggregating major protocols
Reachability depends on the counterparty VASP’s network
not published
Reference OPEX: KYT $30–120K/yr · Travel Rule $15–60K/yr · sanctions/PEP $10–40K/yr · KYC $1–3/check (cheaper via local-market IDV vendors). EU TFR threshold is now zero; several regulators require originator/beneficiary data with no de-minimis.
Vendor
Out of the box
Watch-out
Published pricing (typical)
MoonPay
Widest-known widget on/off-ramp, cards + wallets
Highest fees of the majors
~4.0–5.5%
Ramp Network
Widget on/off-ramp with cheap bank rails
Regional coverage narrower than MoonPay
SEPA ~0.49% · card ~2.9%
Transak
On/off-ramp incl. local rails; locally registered in several markets
Coverage gaps by state/market — verify yours
~1–3%
Banxa
Listed provider, broad payment-method coverage
Mid-pack pricing
card ~2.99–3.99% · SEPA ~1.99%
Mercuryo
On/off-ramp with strong SEPA Instant rails
Card side is pricey
SEPA ~1.95% · card ~3.95%
Pattern from deals: ramp aggregators are the MVP fast-track; direct banking rails come later and are never advertised — a discovery item, not a checkbox.
Vendor
Out of the box
Watch-out
Published pricing
B2C2
Institutional OTC liquidity / electronic LP
OTC LP model, not designated MM on your books by default
not published
GSR / Wintermute
Global algorithmic market making across CEX + DEX venues
Prioritize larger venues and tokens
not published
FalconX
Prime brokerage: execution, credit, custody access
Multi-asset trade surveillance for the largest venues
Big-institution pricing and implementation weight
not published
Solidus Labs / Eventus
Crypto-native and mid-market surveillance (wash trading, spoofing, cross-venue)
Coverage DNA differs — crypto-native vs multi-asset
not published
Reference: MM retainers ~$10–50K+/mo, quote-based. A pragmatic MVP alternative is a vendor liquidity bridge — with an exit plan to direct arrangements.
Covered
What the box does well
Matching engine and order books
Spot trading UI (web)
Hot wallets (basic)
Admin panel, accounts, standard listings
Charting
Partial
Exists — needs a wrapper
KYC (a vendor hook, not your market’s onboarding flow)
Fiat gateway (generic PSPs, not your local rails)
AML hooks (no casework, no Travel Rule ops)
Mobile apps (templated), API gateway, generic reporting
Liquidity arrangements; own-token listing freedom; derivatives stack on most cores
The honest score
In our module-level gap analysis of a white-label-based offer against a full institutional scope, the box genuinely covered about 11% of the modules, partially covered a third, and left the majority to custom build. The box is not a scam — it is a start. Price the other 89% before you sign.
Aggregate third-party TCO seen across exchange deals: one-off $85–270K, annual $293K–1.47M. Vendor facts current to mid-2026; verify at contract time.
02 · Build vs buy · No strawmen
Three routes — including the one that pays us the same and locks you in
Each route below is a real delivery we would sign up for. The matrix shows the trade-offs; the watch-outs are the ones we say in the room.
The three routes
Comparison matrix
Also evaluated — and parked
Route 1
Vendor core + custom market layer
The engine, order books and admin come from the box. Your market layer — local rails, reporting, tax mechanics, your listings policy — is built beside it.
Fastest first trade
Vendor carries engine hardening
Smallest first budget
Core stays the vendor’s IP
Roadmap capped by vendor releases
Rev-share / lock-in economics
Watch-out: the box covers the order book, not your market. The market layer is a custom build on this route too.
Indicative build
$50–150K
Plus
market layer
First trade
fastest
Exit story
re-platform
★ Route 2 · Recommended for most
Progressive / composable
Your contracts, data model and code from day one; vendor components behind adapters ship the MVP at near-box speed. Implementations degrade — contracts never do: every rented piece stays swappable.
Near-vendor time to market
IP and data model yours from day one
No scaling ceiling by design
Clean licence story for regulators and investors
Adapter discipline must be enforced in code review
Slightly higher first budget than Route 1
Watch-out: without discipline the adapter boundary erodes — and you have quietly bought Route 1 at Route 2 prices.
Indicative build
$150–500K
Plus
market layer
First trade
near-vendor
Exit story
none needed
Route 3
Fully custom
You build the engine the vendors spent years hardening. Total control, total responsibility — justified when derivatives mechanics or exotic market structure genuinely demand it.
Total IP control
No ceiling, no vendor economics
Exotic market structures possible
Slowest to first trade
You own every failure mode
Largest budget
Watch-out: it pays us more and delays your launch. We recommend it only when the maths of your market demands it.
Indicative build
$300K–1.5M+
Plus
market layer
First trade
slowest
Exit story
you are the platform
Route 1 · Vendor + layer
★ Route 2 · Composable
Route 3 · Custom
Ownership & IP
Code & contracts ownership
✕vendor’s core
✓yours from day one
✓total
Own-token / listings freedom
◖vendor policy applies
✓yours
✓yours
Delivery characteristics
Time to first trade
✓fastest
✓near-vendor
✕slowest
Market layer (rails, reporting, tax)
✕custom on every route
✕custom on every route
✕custom on every route
Risk & growth
Vendor lock-in
✕structural
✓every piece swappable
✓none
Scales past MVP without rebuild
◖until the ceiling
✓by design
✓by design
Watch-outs — the trade-off you accept
The honest one
re-platforming later costs more than Route 2 would have
Live in weeks on a major exchange’s infrastructure. Ruled out for most: you cannot list your own token or stablecoin in your own order books, and the economics are permanent rev-share. Parked for franchise-style ventures.
Evaluated
Pure open-source core
Full source ownership at licence-price zero. Ruled out as a primary route: you inherit the maintenance burden on day one without the vendor’s hardening cadence. Viable inside Route 2 as one adapter among several.
Evaluated
Standalone matching-engine licence
Institutional engines (SaaS or licensed) are excellent — and only ~10% of the scope. Sensible inside Route 2 or 3; not a route by itself. Parked.
Budget figures are indicative corridors at a blended rate, before the market layer; the matrix criteria mirror the ones we use in delivery grammar internally: time-to-market, IP control, lock-in, scaling ceiling.
07 · Licensing map · Facts current to mid-2026
Where exchanges get licensed — and what changed in 2026
Twenty-plus regimes, one table. The dates matter: several markets closed their transition windows this year — sequencing the licence is now part of the build plan, not an afterthought.
Europe
Americas
Middle East & Africa
Asia-Pacific
Market
Regime · licence
What is distinct · 2026 status
EU / EEA
MiCA — CASP authorisation
One licence passports to 30 states. Transition ended 1 Jul 2026; ~204 CASPs authorised, unlicensed firms must exit.
Norway
Crypto Asset Act (MiCA via EEA)
Same CASP regime, offset transition closed 30 Jun 2026; local venues already authorised.
UK
FCA — FSMA regime, QCATP category
Brand-new full regime: final rules Jun 2026, application window Sep 2026–Feb 2027, fully live Oct 2027.
Switzerland
FINMA — FinTech / securities-firm + DLT facility
Reputation-grade; dedicated crypto-institution licence category expected from 2027.
Market
Regime · licence
What is distinct · 2026 status
USA
FinCEN MSB + SEC/CFTC + state MTLs; NY BitLicense
Highest-cost patchwork (45+ state licences). Stablecoin law in force; market-structure bill cleared committee, not yet law mid-2026.
Canada
CSA/CIRO — investment-dealer registration
Platforms regulated as securities dealers; 4-tier custody framework (2026). Strict.
Brazil
BCB — VASP authorisation
Effective Feb 2026: capital ~$2–7M, monthly proof-of-reserves, existing firms deadline 30 Oct 2026.
Mexico
Fintech Law (ITF)
Grey-light: regulated entities restricted from public crypto offering; exchanges operate under AML reporting.
Fastest GCC route; often obtained first while other applications run in parallel.
Turkey
CMB — CASP licence
Capital ~$4.1M; unlicensed operation criminal; the 30 Jun 2026 deadline for unlicensed firms has passed — confirm current status before relying on this line.
Kenya operationalising 2026; South Africa most mature African pipeline (310 approved).
Market
Regime · licence
What is distinct · 2026 status
Singapore
MAS — MPI (DPT services)
High bar, top credibility; 37 active holders; overseas-only DTSP licences effectively not issued.
Hong Kong
SFC — VATP licence
13 licensed platforms (29 May 2026), 6 applications pending. 98% of client assets in cold storage; assets held via a wholly owned HK subsidiary with a TCSP licence. Circular of 3 Nov 2025 allows a shared order book with a licensed global affiliate, on approval and full pre-funding.
Japan
FSA registration + JVCEA
Regime mid-upgrade: 2026 FIEA amendment moves crypto into securities law; flat 20% tax from 2028.
South Korea
FSC/FIU — VASP + VAUPA
Real-name bank accounts; effectively closed to foreign platforms without local structure.
Australia
AFSL (Digital Asset Platforms) + AUSTRAC
Licensing cliff: existing platforms had to lodge AFSL applications by 30 Jun 2026.
India
FIU-IND registration (PMLA)
AML-registration regime (54 entities), not a market-structure licence; 30% tax + 1% TDS; travel rule with no de-minimis.
Kazakhstan
AIFC — AFSA trading-facility licence
~$200K capital, ~6–7 months; crypto legal inside the AIFC perimeter; active regional hub.
Sequencing is a strategy. Real programs often stack licences — a fast first regime for launch, a passporting regime for scale — and the entity structure has to be designed for that on day one. This is a discovery workstream, not a legal footnote.
Summary only, not legal advice; regimes verified against primary and legal-industry sources, mid-2026. Your counsel owns the licence; we build to its conditions.
08 · Delivery proof · What we have actually shipped
The engagements behind everything above
Every corridor, vendor watch-out and licensing note in this workspace came out of real builds. Here they are — split honestly into what we shipped and what we architected, because conflating the two does not survive a technical call.
6production systems we built that are still operating
8vault tiers in a live custody topology
2institutional exchange architectures specified end to end
One engagement below is named, live and independently verifiable — start there if you want to check us before reading the rest. The others are described without client names or jurisdictions: the architecture and the trade-offs are what transfer, the logos do not. Named references for those are available under mutual NDA.
Built and running
Architected and costed
Where the line is
Production · licensed bank
Digital-asset platform for a licensed bank
custody · vault topology · ledger · treasury · AML
Hybrid omnibus custody: per-customer deposit addresses, threshold sweep into an omnibus vault, MPC key management, four-eyes withdrawal approval.
Eight-tier vault topology — customer, per-user quarantine, omnibus, withdrawal, warm, company, gas station, cold — with automated top-up between tiers and safety interlocks.
Self-hosted double-entry ledger: per-user, per-network, per-asset balances; internal transfers settle off-chain with no gas.
Durable workflow orchestration on every money movement, with compensation steps: reserve, settle, revert.
AML and KYT as a hard gate before broadcast, with per-user quarantine for flagged deposits and manual-only release.
Operations portal: fee policy, kill switch, granular per-asset and per-network blocking, full audit trail.
The operational core of an exchange, in production: custody, ledger, treasury and compliance as one consistent system — 4 EVM networks, ~12 engineers, phase one in 3 months.
Production · named client
Haust Network — trading venue on a zk-rollup L2
named · live mainnet · publicly verifiable
Uniswap-v3-based venue: concentrated liquidity, configurable fee tiers per pool, custom price ranges, LP positions issued as ERC-721.
Custom liquidity-incentive module beyond swap fees, with LP-token staking and pro-rata reward accrual by share and elapsed time.
Cross-chain liquidity through AggLayer's unified bridge — the token trades on the L2 venue and on Ethereum L1 concurrently.
Account abstraction in Rust across ERC-4337, ERC-6900 and ERC-7579: paymaster-sponsored gas, fees payable in any ERC-20, batch transactions, session keys, guardian recovery.
Purpose-built lightweight multi-sig on that abstract-account system after rejecting an off-the-shelf vault as too heavy.
Overcollateralised lending on an Aave-v3 base, adapted to the same account model.
Mainnet live since October 2025 · 10.4M wallets and 15.4M transactions through the testnet phase · engagement running since 2024 and extended by the client into a second product.
Production
Order execution and delegated signing layer
order lifecycle · deferred signing · embedded wallets
Market, limit and recurring order types over one order model — a parent order record with type-specific child tables, so the lifecycle stays uniform while parameters differ per type.
Interactive and deferred signing separated properly: interactive orders signed client-side; scheduled orders signed at execution time by a service holding delegated authority through an MPC provider, behind a boundary never exposed to the client.
Event-driven data plane: chain streamers produce to a single trade-event topic; catalog, history, live broadcast and notification consumers attach without touching each other.
Per-user notification channel correlating on-chain transaction signatures back to order records, regardless of which side broadcast.
OHLC aggregation with idempotent upserts and backfill markers, so re-aggregation after a restart cannot double-count.
Order lifecycleDelegated signingMPC embedded walletsEvent-driven
Six services on one event backbone — order lifecycle, signing authority and market data separated cleanly enough that each scales on its own.
Production
Market-making engine for an exchange operator
liquidity · smart order routing · hedging
Purpose-built market maker in Go after rejecting the off-the-shelf framework — the hot path and the exchange connector both failed the requirement.
Symmetric bid/ask grid pricing with an inventory-aware model on the roadmap; live reconfiguration without restart.
Smart order routing through an execution gateway, with hedging legs into two major external venues.
Freeze and recovery on connectivity loss or net-delta breach — the venue stops quoting rather than accumulating silent exposure.
Full observability stack with metric, log and trace pipelines and alerting into team channels.
GogRPCKubernetes OpenTelemetry
A venue that can quote its own book from day one instead of waiting for external market makers to show up.
Production
Multi-chain custody and wallet infrastructure
omnibus vs segregated · taint · sweeping · AML
Custody model decided in engineering detail rather than by preference: omnibus versus segregated, with taint and quarantine consequences spelled out separately for UTXO and account-based chains.
Sweeping strategy, intermediate vault design and withdrawal-wallet sizing tied to actual flow volumes.
Multi-chain across Bitcoin, Ethereum, XRP and stablecoins on both ERC-20 and TRC-20 rails.
Gas economics: network-fee prediction and energy staking on the low-fee chain to cut per-withdrawal cost.
Internal off-chain ledger for settlement between platform accounts with no on-chain cost.
MPC custodyBTC · ETH · XRP · TRONChain analyticsTravel Rule
The custody and settlement layer of an exchange, built for a live multi-chain platform and priced against real gas economics.
Production
Compliance surface: KYC, KYT and Travel Rule
onboarding · screening · sanctions · case management
Provider-agnostic KYC layer behind an interface, so the onboarding vendor is a configuration decision rather than a rewrite.
Risk-category to action mapping — exchange, gambling, mixer, darknet — resolved into hard block, manual review or pass.
Address screening and transaction monitoring on deposit, withdrawal and counterparty paths, with a dust threshold that filters noise before the paid API call.
Travel Rule with hosted and unhosted wallet classification and proof of ownership.
Case management and an audit trail sized for a regulator, not for a dashboard.
KYC / KYBKYT screeningTravel RuleBiometrics
Onboarding and monitoring built once as a reusable surface across several regulated platforms, not bolted on per venue.
An earlier full CEX stack — trading core, wallets, back office and compliance surface — also sits in the portfolio; it is no longer operated by its owner, which is why we lead with the systems above.
Architecture
Architecture audit of a live trading backend
Full architectural audit of a trading system, written for client leadership and external reviewers rather than as an internal note.
Eight design decisions documented as strengths, eleven open risks ranked by exposure, a ten-item remediation list ordered by impact-to-effort.
Findings named plainly: an unauthenticated market-data websocket, missing idempotency on order submission, an undocumented key-storage policy, no reconciliation between on-chain broadcast and the order record, synchronous coupling inside the live-broadcast hot path.
Every finding traced to documented behaviour, with uncertainty named as uncertainty rather than asserted as implementation detail.
Eleven risks named in our own build before anyone else could name them — the same review we run on an exchange before it takes customer money.
Architecture
Institutional exchange architecture review
Independent review of a tokenized-equities venue: we showed the published performance targets could not be met on the stack the incumbent had proposed, with the reasoning laid out rather than asserted.
Target architecture: matching engine in Rust with FIX 4.4 / 5.0 SP2 plus a binary API for latency-sensitive flow.
Settlement on a high-throughput chain with permissioned transfer hooks for regulated instruments.
Phased plan with ranged estimates per phase, so scope could be cut against budget rather than against quality.
An architecture review that changed what the venue was going to build — including telling them what would not work.
Architecture
Full exchange build: scope and estimate
Complete work breakdown for a full exchange: spot, margin and futures, automated order matching, maker-taker fee tiers, staking, launchpad, P2P lending, payment gateway, proof of reserves.
Custody design with cold storage and staged key handling; KYC with live face recognition plus AML screening.
Module-level hour ranges across a defined team shape and a phased timeline, decomposed far enough that scope could be cut against budget.
Annual infrastructure cost modelled separately from build cost, so operating burn was visible before signature.
One of the decompositions behind the corridors in section 04 — the estimation library is built from engagements like this, not from a rate card.
A full-scope exchange broken down to modules, team shape and infrastructure burn — the level of detail a board can be shown before signature.
The fastest way to lose a technical evaluation is to be caught overstating one thing. So here is the boundary, unprompted.
Run in production
Proven, with systems still operating
Custody and vault topology at eight tiers, with quarantine, sweep and automated inter-tier movement.
Double-entry ledger with off-chain internal settlement and idempotent postings.
Order execution and routing across multiple venues, with embedded MPC wallets.
Market making with quoting, smart order routing, external hedging and freeze-on-breach.
Compliance: KYC, KYT, sanctions, Travel Rule, quarantine and case management under a real regulator.
Purpose-built for you
Not previously shipped — and priced as new work
The matching engine. Our live venue is an AMM, not a central limit order book — different mechanics, and we will not blur the two. We have architected an institutional CLOB and estimated a full one, but not shipped one.
Derivatives risk and liquidation. Specified and estimated, not previously delivered end to end.
Throughput claims. We will size a matching core against your instrument set and flow profile. We will not repeat a benchmark number we have not measured.
Licensing and market structure. We build to your counsel's regulatory posture; we do not supply the licence or the legal opinion.
Why this section exists
Every bidder you meet will claim the matching engine. Ask each of them the same question we just answered: which of these have you run in production, and which are you building for the first time on my budget?
Engagements described without client names except where the client is public. Named references available under mutual NDA.
09 · Reference architecture · What actually gets assembled
The stack behind the eight steps
Section 05 shows what one order has to survive. This is the machine that survives it — and where each part comes from. Red outline: built by us and proven in production. Grey: an integration we already run. Dashed: purpose-built per venue, because no shortcut exists.
Built by us, proven in productionIntegration we already runPurpose-built per venue
Layer by layer
Vault topology
Demo stand
Vault topology ours
Eight tiers in production: customer, per-user quarantine, omnibus, withdrawal, warm, company, gas station, cold. Automated top-up between tiers with a safety interlock that suspends automation after repeated emergency refills instead of silently draining the floor.
Ledger integration
Self-hosted double-entry ledger as the single source of truth. Every trade, fee, deposit and withdrawal is a balanced posting with an idempotency reference, so webhook redelivery is safe and reconciliation is a query rather than a monthly fire drill.
Treasury automation ours
Sweep-on-threshold from customer addresses, scheduled and floor-triggered refills, per-asset minimum and target balances. A custody vendor's native rebalancing covers a couple of vaults; everything past that is webhook-and-worker logic someone has to write.
Custody integration
MPC custody in production, abstracted behind a provider interface. Hot and cold cannot share a workspace on the platform — that constraint shapes the topology, and knowing it in advance is worth more than a slide about it.
Gas circuit breaker ours
Per-network fee monitoring with normal, elevated and spike modes against a rolling baseline. In spike mode withdrawals queue FIFO per network with a TTL and drain at a metered rate. Fee tiers are sized from the 95th percentile of observed cost, not guessed.
Kill switch ours
Not one button: a pricing state machine with automatic and manual transitions, granular blocking per asset, network and operation, manual override behind four-eyes approval with a mandatory reason code. Internal transfers keep working while external flow is halted.
Compliance integration
KYC behind a provider-agnostic interface, chain analytics for transaction and address screening, Travel Rule with hosted and unhosted classification, per-user quarantine with manual-only release. Never an automatic allow.
Matching engine purpose-built
The order book is built for the venue, not reused from a previous one — instrument set, fee model, latency target and settlement path all change the design. We have specified an institutional core in Rust with FIX and a binary API; the throughput profile gets sized against your actual flow rather than quoted as a headline number.
The eight-tier topology running in production. Every arrow is a policy someone has to write, test and be able to defend to an auditor — none of it comes with a custody vendor, and none of it is in a white-label box.
Vault we design and operateIsolation tier Deep coldOutside the vault perimeter
Why quarantine is its own tier
A flagged deposit that lands in the omnibus vault has contaminated the pool — on UTXO chains permanently. Isolating it per user, before the sweep, is the difference between one frozen balance and a custody-wide taint problem.
Why a gas station
Every sweep and every refill costs native gas on its own network. Without a dedicated funded tier, treasury automation stops silently at the worst possible moment — during the volume spike that triggered it.
Why the interlock
Automation that keeps topping up a draining float will drain it faster. After repeated emergency refills the system suspends itself and asks a human, instead of executing the incident.
This is the layer no vendor box ships and no custody provider replaces — a provider's native rebalancing typically covers a pair of vaults. Everything past that is policy code someone writes. Where a regime sets a hard cold-storage ratio — Hong Kong requires 98% of client virtual assets in cold storage, with compensation arrangements over 50% of cold and 100% of hot holdings — this diagram stops being an engineering artefact and becomes licence evidence.
Walkthrough
What the stand shows
Spot and derivatives markets; order placement directly from the chart.
Limit, stop-limit, stop-market, price alerts; order book, open orders, trade history.
Sub-accounts with instant switching; wallet, deposits, asset overview.
AI assistant for balances, positions and order entry.
Referral tiers, API keys for trading bots, key management.
Back office: listings, market pause, fee and asset configuration.
Vault view: warm / hot / omnibus with rebalancing thresholds.
Read this first
How the stand differs from production
Key management on the stand runs through a simplified provider service without MPC, so the environment stands up quickly across many assets. In production it is replaced by an MPC custody provider through configuration — the interface does not change. Market data on the stand is a controlled feed; production connects to live venues and to your own liquidity arrangements.
We show a stand rather than a live venue on purpose. The exchanges we built earlier belong to their owners and several no longer operate. Screenshots of dead products prove nothing; we would rather run the architecture in front of you and walk the production integrations case by case.
Sequencing: phase zero maps jurisdiction, instruments, custody and banking partners into an architecture decision record. Phase one is the tradable venue — spot core, ledger, custody, treasury, compliance, back office. Phase two adds derivatives, risk, liquidity connectivity and institutional APIs on a core already proven in operation.
10 · Security & assurance · The section we opened in 01 and owe you
Custody is where exchanges bleed — so here is the rest of that sentence
Section 01 says the large losses were custody-operations failures rather than matching-engine failures. That is easy to write and worth nothing on its own. This is the operational answer: who can move funds, what stops them, what happens in the first thirty minutes, and how you prove solvency to a regulator who is not taking your word for it.
Keys & authority
Incident response
Proof of reserves
The design question is never “is the key safe”. It is which combination of humans and systems can move customer funds, and what has to fail simultaneously for that to happen by accident or under coercion. Answer that on a whiteboard before choosing a custody vendor — the answer constrains the vendor, not the other way round.
Separation
Three roles that must never be one person
Requests a withdrawal — operations or the automated treasury worker.
Approves it — a second human, above a threshold, with a mandatory reason code recorded against their identity.
Changes the policy that defines the threshold — a third role, on a different approval path, because whoever can lower the limit can bypass the limit.
The third one is the one teams forget. A four-eyes rule that a single admin can disable is theatre.
Where policy lives
Outside the application
Transaction policy sits in the custody layer, not in application code — a compromised backend then cannot authorise a transfer it was never allowed to authorise.
Signing quorum defined per vault tier: the hot float and the cold reserve do not share a policy, and on most platforms cannot share a workspace.
Withdrawal allowlists with a cooling period on new destinations. Instant allowlisting is how drained accounts stay drained.
Kill switch granular to asset, network and operation, with internal transfers still clearing while external flow is halted.
Ceremony
Key generation and recovery
Generation as a witnessed ceremony with a written script, recorded participants and a signed record — if the phrase “we set it up on a laptop” applies, the licence conversation gets harder.
Share distribution across roles and locations so no single custodian, office or jurisdiction reconstitutes the key.
Recovery rehearsed, not documented. An untested recovery procedure is a hypothesis.
Rotation and offboarding: a departing engineer must lose signing authority the same day, and that must be provable afterwards.
Float discipline
Sized to flow, not to convenience
The hot float is the maximum you can lose in one event. Size it from observed withdrawal volume, not from how often ops want to top up.
Automated refills from warm, with the safety interlock that suspends automation after repeated emergency refills instead of feeding a drain.
Balance drift between chain state and the ledger is an alert, not a monthly reconciliation finding.
Quarantine tier for flagged deposits so a screening hit never contaminates the pooled vault — on UTXO chains that contamination is permanent.
Every control above exists in a system we run in production. Section 09 shows where each one sits in the topology.
An incident plan that lives in a document nobody has rehearsed is not a plan. This is the shape we build and drill.
Window
What happens
What has to exist beforehand
Detection continuous
Triggers, not intuition: withdrawal rate above the rolling baseline, balance drift between chain state and ledger, a screening hit on an outbound path, signing requests outside the expected pattern, RPC or node behaviour that stops matching the network.
Alert thresholds defined per asset and per network, routed to a human who is awake in that timezone.
First 30 minutes contain
Halt external flow at the granularity of the problem — one asset, one network, one operation — while internal transfers and trading keep clearing. Freeze treasury automation so it stops refilling a vault that is being emptied. Snapshot ledger state before anything is remediated.
A kill switch that is granular and rehearsed. A blunt “stop everything” button costs you the incident and the business day.
Hours 1–4 establish facts
Reconstruct from the ledger and the audit trail: what moved, on whose authority, through which policy. Separate customer-asset impact from operational-asset impact, because the regulator and your users are asking different questions.
An immutable audit trail that records the authorising identity and reason code, not just the transaction.
Regulatory clock jurisdiction-set
Notification obligations start running from detection in most regimes — not from the point you understand the cause. The first notification is usually made before the facts are complete, and it has to be accurate about what is and is not yet known.
A named accountable person, a pre-agreed template, and counsel who has seen the draft before the incident.
Resumption gated
Restart behind explicit gates: reconciliation clean, root cause identified, control changed. Not “it seems fine now”. Each gate is signed off by a named role.
Written resumption criteria agreed while nobody is panicking.
Rehearsal quarterly
Tabletop the scenarios that actually happen: a drained hot wallet, a compromised operator account, a custody provider outage, a chain reorg, a bad listing. Measure time-to-containment and fix whatever was slow.
Calendar time and executive attendance. Without the second, the first is a workshop.
The uncomfortable one
Ask every bidder for their incident runbook and the date of their last rehearsal. Most will send you a security architecture diagram instead — that is the answer to a different question, and the substitution tells you what you need to know.
Proof of reserves is not an audit and does not prove solvency on its own. It proves that at a point in time, the assets you control covered the liabilities you admitted to. The hard half is the liabilities — anyone can show a wallet balance.
Assets
The easy half
Address attestation: prove control of the addresses holding customer assets, with signed messages or on-chain proofs at a fixed block height.
Full disclosure of the address set. A selective disclosure proves selective solvency.
Snapshot at a committed height so the figure cannot be assembled after the fact from borrowed funds.
Liabilities
The half that decides whether it means anything
Merkle commitment over every customer balance, published so each user can verify their own balance is inside the tree without seeing anyone else's.
The tree is only as honest as the ledger under it — which is why the double-entry ledger in section 09 is the load-bearing component, not a nicety.
Negative and omitted balances are the classic manipulation. The construction has to make exclusion detectable, not just inclusion provable.
Cadence
Frequency and independence
A one-off publication is marketing. Recurring publication on a fixed schedule, with a third party attesting to the method, is evidence. Decide the cadence before launch — retrofitting it onto a ledger that was not designed for snapshots is expensive.
Design consequence
It reaches back into the build
Point-in-time balance snapshots, an address registry that is complete by construction, and an append-only history you can replay. These are architecture decisions in phase one, not a reporting feature bolted on in phase three.
Honesty
What it still does not prove
It says nothing about undisclosed off-balance-sheet obligations, encumbered assets, or the hour after the snapshot. Say so publicly. A venue that explains the limits of its own proof is more credible than one that overstates it.
In regimes that mandate a cold-storage ratio for client assets, the vault topology in section 09 and the reserve proof are the same evidence viewed from two directions — design them together.
11 · Migration · For the answer the route finder hears most
Getting off a platform you already run
“On a white-label, hitting its ceiling” is one of the five starting points in section 03 — and the one with the most at stake, because you are moving a live venue with real customer money rather than starting clean. Nothing here is theoretical: it is the sequence that keeps a venue trading through the switch.
Before anything
Find out what you actually own
Data export rights: order and trade history, customer records, ledger entries — in what format, at what notice, and does the contract let you take it at all.
Custody: are the keys yours, the vendor's, or a shared arrangement. This single answer determines whether migration is an engineering project or a negotiation.
Notice period and termination triggers. Discovering a twelve-month notice clause mid-migration changes the plan and the budget.
Do this first. It is a week of reading and it decides everything after.
Then
Run both, prove one
Stand up the new stack in shadow: same market data, same order flow replayed, no customer traffic.
Reconcile continuously against the incumbent — balances, fills, fees. Differences are the specification of what you misunderstood.
Dual-run until the delta is explainable rather than merely small.
Cutover
The narrow window
Read-only period announced in advance: trading halted, withdrawals halted, deposits queued.
Final reconciliation as a hard gate — if it does not balance, you roll back, and the rollback path stays live until it does.
Custody handover: address continuity or a controlled sweep, with the customer-facing deposit addresses handled deliberately. Customers who deposit to an old address after cutover are a support incident you can design out.
Resume in stages — deposits, then trading, then withdrawals — so each is observed before the next.
Carries over
What has to survive the move
Balances to the smallest unit, with the ledger able to prove the opening balance equals the closing balance on the old platform.
Trade history — users, tax reporting and the regulator all expect continuity across the seam.
KYC state and risk scoring, so customers are not re-onboarded and the AML record is unbroken.
API keys and bot integrations, or a documented cutover window for institutional users — they need more notice than retail.
Watch-out
Where migrations actually fail
Custody. If key material is not portable, the venue moves funds on-chain — which is cost, exposure and a screening event on every transfer.
Rounding. Different internal precision between platforms produces balance dust that becomes a reconciliation problem at scale.
The undocumented behaviour. Fee edge cases and order-lifecycle quirks that live in the old system's code and in nobody's specification. Shadow running is how you find them before customers do.
Announcing too late. Institutional users need lead time; retail needs clarity. Silence reads as instability.
The strategic point
Migration cost is the real price of the cheapest route. Section 02 puts it plainly: re-platforming later costs more than owning the contracts from day one would have. If you are reading this section because you are already on a box, that number is no longer hypothetical for you — and it is the strongest argument you have in your next vendor negotiation.
Sequencing, dual-run duration and the reconciliation gate are scoped in discovery against your contract terms and your custody arrangement — those two constrain the plan more than the engineering does.
04 · Investment corridors · No line-item calculator, on purpose
Honest bands — and what moves a project inside them
A per-feature price list on a public page is theatre: padded or wrong, and your scope is neither ours nor your competitor’s. These are the corridors our estimation library actually produces.
Spot exchange MVP on a vendor core
Engine and order book from the box, custom market layer beside it
$50–150K
Composable venue, owned from day one
Route 2: your contracts and data model, vendor components behind adapters
$150–500K
Custom venue end to end
Own core, custody integration, admin, compliance surface
$300K–1.5M+
Tokenized-securities venue with a stablecoin rail
Hybrid exchange / broker / issuance — across scenario decompositions
$270–980K
Custodial wallet stack (licensed markets)
MPC custody, AML pipeline, back-office — before the venue itself (≈5,800–7,650 engineering hours)
$290–380K
A build number is not a year-one number — and this is where fixed budgets get spent before launch.
The bands above cover build only. A licensed venue going live in year one also carries the market layer for its jurisdiction (custom on every route, sized in discovery), third-party setup of roughly $85–270K one-off, and recurring vendor cost of $293K–1.47M a year for custody, KYT, travel rule, surveillance and market data — reference lines are in section 06. If custody is not already inside your chosen band, the custodial stack is a further $290–380K.
In practice a build figure of $150–500K can sit inside a year-one commitment two to three times larger. Any bidder quoting a single number without separating build, market layer, one-off setup and annual run cost is quoting the part that is easiest to win on. Ask all of them to split it the same four ways, then compare.
What moves the number
Matching engine: adapter to a proven engine vs building your own — the single largest swing.
Derivatives: perps, margin and options add risk engines, liquidation logic and a heavier licence posture.
Market layer: local rails, reporting formats and — in some markets — per-trade tax mechanics.
Custody model: integrated MPC vendor vs self-hosted infrastructure; shapes the licence too.
Liquidity: market-making arrangements and asset-onboarding pipelines.
How the number gets exact
A short discovery maps your requirements onto the module decompositions behind these corridors. You get a phased plan with hour ranges per module, written assumptions, and gates where you can stop. The corridor becomes a number you can defend to your board.
Bring your vendor shortlist — we map it module-by-module (covered / partial / missing) and tell you which route wins on your constraints, even if that route is not ours.
An exchange is a regulated machine — built to be owned, not rented
The hard part is never the order book. It is the regulated plumbing around it: vault topology, sweep and rebalancing policy, ledger consistency, withdrawal authority, and the compliance surface wrapped around all of it. A vendor box covers the book and stops there; the market layer is a custom build on every route, including the cheapest one.
Route 1 Vendor core + custom market layer$50–150K buildFastest first trade. Core stays the vendor's IP; roadmap capped by their releases.
Route 2 Progressive / composable $150–500K buildYour contracts and data model from day one, vendor components behind adapters. Recommended for most.
Route 3 Fully custom$300K–1.5M+ buildTotal control and total responsibility. Justified when market structure genuinely demands it.
Custodial wallet stack alone — MPC custody, AML pipeline, back office, before the venue itself — runs $290–380K. Third-party OPEX (custody, KYT, travel rule, market data) is budgeted separately.
Run in production
Custody and vault topology at eight tiers, with quarantine, sweep and automated inter-tier movement
Double-entry ledger with off-chain internal settlement and idempotent postings
Treasury automation: thresholds, refills, safety interlocks, gas circuit breakers
Order execution and routing across multiple venues, with embedded MPC wallets
Market making: quoting, smart order routing, external hedging, freeze-on-breach
Compliance: KYC, KYT, sanctions, Travel Rule, quarantine and case management under a live regulator
Purpose-built for your venue
The matching engine. Our live venue is an AMM, not a central limit order book. We have architected an institutional CLOB and estimated a full one — we have not shipped one, and we price it as new work
Derivatives risk and liquidation. Specified and estimated, not previously delivered end to end
Throughput. Sized against your instrument set and flow. We do not repeat benchmark numbers we have not measured
Licensing. We build to your counsel's regulatory posture; we do not supply the licence
Proof you can check without us
Haust Network — trading venue on a zk-rollup L2. Uniswap-v3-based venue with concentrated liquidity and custom liquidity incentives, cross-chain liquidity via AggLayer, account abstraction in Rust across ERC-4337 / 6900 / 7579, lending on an Aave-v3 base. Mainnet live since October 2025; 10.4M wallets and 15.4M transactions through the testnet phase; engagement running since 2024 and extended by the client into a second product.
Eight further engagements — a licensed bank's digital-asset platform, multi-chain custody, market making, order execution, an institutional exchange architecture review — are described without client names. Named references under mutual NDA.
How the number gets exact
A short discovery maps your requirements onto the module decompositions behind these corridors. You get a phased plan with hour ranges per module, written assumptions, and gates where you can stop. Phase one is the tradable venue: spot core, ledger, custody, treasury, compliance, back office. Phase two adds derivatives, risk, liquidity connectivity and institutional APIs on a core already proven in operation.
Bring your vendor shortlist. We map it module by module — covered, partial, missing — and tell you which route wins on your constraints, even when that route is not ours.
Ask every bidder the same question: which of these have you run in production, and which are you building for the first time on my budget?