01 / Prove
Symbolic execution, not pattern matching.
Halvard checks the stated contract rules across modeled execution paths and refuses to turn unknowns into fake passes.
halmos.run → property: no unauthorized drain → verdict: SHIP
Smart contract security with receipts
Don’t trustthe audit.Re-run it.
Halvard turns crypto security from a PDF into a re-verifiable system: prove the contract before launch, watch the chain while it is live, and rewind any incident with exact state diffs.
Symbolic proofCodehash certificateLive threat patrol
001 · The problem
A scanner gives guesses. An audit firm gives a report. But smart contracts do not care about confidence. Once code is live and holding money, “looks safe” is not enough.
The new security product is proof you can verify.
Rule 01
If the prover cannot prove the claim, the system does not dress it up as safe.
Rule 02
Every green result must survive a deliberately broken twin that the same harness catches.
Rule 03
Every certificate is tied to the exact deployed bytecode, not a hand-wavy repo snapshot.
02 / Certify
A certificate your client can re-run.
The proof is bound to the contract’s codehash, so a skeptic can verify the result against what is actually deployed.
halvard.proof-certificate/v1 · codehash: 0x8f...91c
03 / Refuse
Honest failure is a feature.
Timeout, missing model, or unsupported property? It reports degraded instead of selling a green badge it did not earn.
verdict: DEGRADED · reason: solver_unknown · billed: false
002 · Full Web3 Security Suite
Before, during, and after the attack.
The Audit plan is not just a prover. It bundles the live defense dashboards too: MEVGuard, mempool monitor, wallet guard, attack simulation, and Time Machine replay.
Positioning line: “Other firms sell a PDF. Halvard sells a security loop — prove it, patrol it, rewind it.”
Before launch
Contract Prover + Proof Gate
Generate or inspect smart contracts, discharge safety properties, and block risky .sol changes before they ship.
While live
Mempool Monitor + MEVGuard
Watch pending transactions, detect suspicious activity, track front-run and sandwich risk, and alert before damage confirms.
User safety
Wallet Guard
Screen dangerous approvals and transaction intent before a signer gives away more access than they meant to.
After incident
Time Machine Forensics
Fork a past block, replay a transaction, compare state before and after, and reconstruct exactly how an incident unfolded.
003 · Horizontal security runbook
One lifecycle, not five disconnected tools.
01 / intent
Describe the contract.
Start from human intent or existing Solidity. Halvard turns requirements into checkable obligations instead of vague audit notes.
02 / build
Generate or inspect code.
For new builds, it can synthesize smart-contract structure. For existing code, it maps rules, harnesses, and risk areas.
03 / prove
Run symbolic proof.
Each supported precondition and postcondition is checked. Unsupported or ambiguous claims are surfaced, not hidden.
04 / challenge
Break the twin.
A deliberately broken version must fail under the same harness. If the system cannot catch the bad one, the good one does not get a fake pass.
05 / certify
Seal the proof.
The output is a signed certificate bound to the exact deployed bytecode hash and ready for client, investor, or exchange verification.
06 / patrol
Watch the chain.
MEVGuard, mempool monitor, wallet guard, and alerting continue after launch, when the real adversaries show up.
07 / rewind
Replay the incident.
Time Machine reconstructs old transactions with state diffs so teams can explain the cause, scope the loss, and patch the next release.
004 · Who buys this
Made for teams where one missed edge case is a headline.
This is sales-led for serious crypto teams: audit shops, protocols, treasury managers, wallets, and incident responders.
Audit firms
Stop selling PDFs. Ship proofs.
Turn repetitive contract checks into signed artifacts clients can independently re-run.
Protocols
Launch with a proof gate.
Block unsafe contract changes before they hit mainnet.
DeFi teams
Watch MEV and mempool risk.
See danger forming while transactions are still pending.
Wallets
Protect signers before approval.
Flag risky approvals and transaction intent before the user signs.
Incident response
Rewind the exploit.
Replay the exact historical transaction and expose before/after state changes.
Investors
Diligence with receipts.
Ask for proof certificates instead of trusting a “security reviewed” badge.
005 · Proof receipt
The audit artifact people can challenge.
The brand promise is not “we are smarter.” It is stronger: your client does not need to believe you. They can rerun the proof and verify it against the live code.
Package this plan ↗12:04:31compiler output lockedok
12:04:34bytecode hash matched0x8f...91c
12:04:39property: no unauthorized withdrawpassed
12:04:42broken twin: unguarded withdrawrefuted
12:04:47coverage: stated clauses dischargedcomplete
12:04:50certificate signedpublic
12:04:52mempool watch attachedactive
250
proof bundles
1k
proof runs
10k
compute credits
006 · The sales angle
Say it like a buyer understands it.
“A scanner spot-checks the bridge. Halvard proves the stated bridge rules and shows the receipt.”
Plain-English analogy
for non-crypto buyers
for non-crypto buyers
“Most audits say trust us. Halvard says check it yourself.”
Hero tagline
simple and memorable
simple and memorable
“Prove it. Watch it. Rewind it. One plan.”
Bundle tagline
before / during / after
before / during / after
007 · Dashboard suite
The tools inside the Web3 security layer.
Clean enough for the homepage, specific enough for serious buyers.
Wallet Guard
Catch dangerous approvals.
Screens transaction intent before signing to reduce wallet-drain risk.
Mempool Monitor
Watch threats before confirm.
Tracks pending transactions and flags suspicious movement in real time.
MEVGuard
See extraction attempts.
Surfaces front-run, sandwich, and arbitrage pressure around sensitive flows.
Attack Simulation
Red-team the contract safely.
Runs defensive simulations to expose exploit paths before attackers do.
Time Machine
Replay the exact block.
Forks historical state, replays transactions, and produces before/after diffs.
NZT-48 CLI
Script the workflow.
Run proof, scans, replay, and monitoring flows from terminal automation.
008 · Audit plan
For audit shops and protocol teams that review contracts constantly.
What they are really buying
A proof factory plus live defense suite.
The pitch: what one traditional audit can cost elsewhere, Halvard gives as a monthly, repeatable proof-and-monitoring workflow for teams that need volume.
Honest scope: Halvard proves stated safety properties within supported bounds. Market risk, oracle economics, liveness, and cross-protocol assumptions must be stated clearly instead of hidden behind fake certainty.
Halvard AuditWeb3 vertical
$4,900 /seat/mo
Built for EVM security firms, audit teams, and protocols that need proof artifacts, dashboards, and forensic workflows in one seat.
250proof bundles / month
1,000deep checks / month
10,000AI credits / month
∞projects
- Signed safety certificates bound to contract codehash
- Contract Prover and proof-gate workflows
- MEVGuard, mempool monitor, wallet guard, attack simulation, and Time Machine included
- Compliance Center with audit trail and exports
- Top-tier reasoning mode and BYOK support
- Failed or misconfigured proof runs should never be sold as success
009 · FAQ
The objections answered before sales gets them.
How is this different from a scanner?
Scanners flag patterns that look risky. Halvard’s prover checks stated safety properties and emits a re-verifiable certificate when those claims are actually supported.
Is this a replacement for every human audit?
No. It is a proof and monitoring layer for supported properties. A credible pitch says what it proves, what it monitors, and what still requires human/economic review.
What happens when a proof is incomplete?
The page should say the truth: unknown, timeout, unsupported, or missing-model results are degraded. No fake green badge.
Why does the Audit plan cost $4,900 per seat?
Because it bundles high-volume proof certificates, deep checks, Web3 dashboards, compliance records, premium model access, and forensic tooling for teams reviewing contracts constantly.
HalvardProof before launch.
Proof before launch.
Patrol after.
Give crypto buyers what they actually need: a safety claim they can challenge, live monitoring they can act on, and incident replay they can understand.