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Navokoj — Verifiable MaxSAT for Hard Planning Problems

The shortest description: Navokoj is a constraint-solving API that returns the best possible answer plus a proof you can verify offline.


What Navokoj Solves#

Every enterprise solves constraint-satisfaction problems under time pressure. Navokoj handles the ones where:

  • The problem is structured (regular schedules, grids, hardware circuits, large graph partitions — not random SAT)
  • Speed matters (real-time decisions, batch re-runs, what-if analysis)
  • Verifiability matters (regulated industries, audit trails, security-sensitive workflows)
  • Disruptions happen (a nurse calls in sick, a truck breaks down, a GPU fails) and you need to repair without restarting

If that sounds like your problem, read the use cases.


The Three Things That Make Us Different#

1. Proofs, not promises#

Every Pro+ response includes a structured proof artifact — assignment + UNSAT cores + derivation graph. Our verifier is open source. You don’t trust us. You download our verifier, run it against our response, and confirm offline. That is the trust model.

For comparison: classical solvers (Gurobi, CPLEX, OR-Tools) give you an answer and ask you to take it on faith. CDCL SAT solvers (Z3, Kissat, CaDiCaL) give you proof artifacts but choke on million-variable industrial problems. We do both.

2. Lock-preserving repair#

When the world changes, we don’t restart from scratch. We preserve the parts of your schedule that already work and adjust only what changed. 847×–12,495× faster than recomputation, with 95%+ of prior decisions untouched.

This is the wedge for hospital scheduling, fleet routing, and GPU cluster allocation.

3. Honest numbers, everywhere#

We benchmark against certified optimal solutions and report the gaps. Our mini engine hits 99.77% satisfaction; we tell you that’s not 100%. We tell you where our solver plateaus (expander graphs, ~90% wall) and where it doesn’t apply (random unstructured SAT). Read the limitations page.


What Customers Run It On#

Academic benchmarks (peer-reviewed test suites)#

Use caseExample scaleResult
University timetabling147K variables, 80M clauses100% solved in 73 seconds
Hardware verification512×512 multiplier, 788K variables100% in 5.9 seconds
Graph coloring (planted)105K variables, 232K clauses100% in 13.78 seconds
Grid / lattice1000×1000 coloring100% in 475 seconds
Spin glass (frustrated)64 spins99.47% in 4.3 seconds
Fluid simulation2D Navier-Stokes99.64% residual reduction, 100,000× faster than CFD

Production performance (live API, 2026-04-04 → 2026-06-19)#

308 production runs. 3.98M clauses processed. Median satisfaction 1.0. Median solve time 65.5 ms.

Production instanceScaleResult
Largest clause-density ever recorded10K vars / 1.65M clauses (165× ratio)100% in 278 seconds
Sub-second structural monster2.5K vars / 122K clauses (49× ratio)100% in 0.296 seconds
Massive variable count49K vars / 73.5K clauses100% in 0.291 seconds
Quality at scale308 production runs79.87% at ≥99% satisfaction; 54.22% perfect

These are not benchmark suite numbers. They are what real customers ran through the Navokoj API over 77 days. Full ledger with all 13 monster runs and the three-modes analysis: NitroSAT production data →

Detailed benchmark methodology →


What It Is Not#

  • Not a general SAT solver. If your problem is random Boolean SAT at the phase transition, use Z3 or Kissat. We win on weighted, structured MaxSAT.
  • Not a ZK proving system. Zero-knowledge is a 2027+ wedge that builds on top of our solver. The proof artifact today is a derivation graph, not a SNARK.
  • Not a real-time control system. Our fastest engine hits ~94% satisfaction in milliseconds. If you need <10ms deterministic response for embedded control, look elsewhere.
  • Not a generic constraint solver for continuous problems. If your objective is differentiable, use gradient descent. We specialize in discrete commitment allocation.

Pricing#

TierPriceWhat you get
Free$01K vars, 5K clauses, 500 req/hr
Dev$99/mo10K vars, 50K clauses, 5K req/hr
Pro$499/mo100K vars, 500K clauses, 50K req/hr, proof artifacts included
EnterpriseCustom ($5K+/mo)Unlimited, on-prem optional, SOC2 in flight

Full pricing details →


Get Started#

# Free tier — no credit card
curl -X POST https://api.navokoj.shunyabar.foo/v1/solve \
  -H "Authorization: Bearer YOUR_KEY" \
  -d '{"num_vars": 1000, "clauses": [[1,2,3],[-1,4]], "engine": "mini"}'

For the technical reader#


See Also#

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