{"uid":"cap_XqN-icC10EeCY9EIKiRAz","slug":"khotem-quantum-circuit-simulator-qsim-60885e92","name":"KHOTEM Quantum Circuit Simulator (qsim)","description":"Paid cryptographic witness services for autonomous agents and humans: seals, attestations, verification, audit, sealed document thread. x402-native micropayments, USDC on Base / Polygon / Solana, direct on-chain verification. No accounts, no API keys, no KYC.","url":"https://khotem.com/api/qsim","method":"POST","headers":{},"bodySchema":{"type":"object","required":["gates","qubits"],"properties":{"gates":{"type":"array"},"shots":{"type":"integer"},"qubits":{"type":"integer"}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"registry","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_qm8s9CV43OKmNU-pU6kLa","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":"0x833589fcd6edb6e08f4c7c32d4f71b54bda02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Simulates a quantum circuit defined by gates and qubits, returning measurement results, paid via x402 micropayment with no account or API key required.","exampleAgentPrompt":"Simulate a 2-qubit quantum circuit with a Hadamard gate on qubit 0 and a CNOT gate targeting qubit 1, run it for 1024 shots, and give me the measurement outcome probabilities — pay with USDC, no account needed.","exampleUseCases":[{"title":"Bell state entanglement simulation","prompt":"Run a 2-qubit Bell state circuit — Hadamard on qubit 0, then CNOT on qubits 0 and 1 — for 512 shots and show me the probability distribution of measurement outcomes."},{"title":"Quantum algorithm prototyping on a budget","prompt":"I'm prototyping a 3-qubit Grover's algorithm circuit with these gates and I want to simulate it for 1000 shots to check the output distribution before I run it on real hardware — can you do that for a small per-call fee?"},{"title":"Randomness source via quantum measurement","prompt":"Set up a 1-qubit circuit with a Hadamard gate and measure it 2048 times so I can use the bit-flip results as a quantum random number source — pay per call with no signup."}],"resultDescription":"Returns shot-based measurement results from the simulated quantum circuit, typically including counts or probability distributions over basis states (e.g. {'00': 512, '11': 512} for a Bell state), representing the statistical outcomes of the specified number of circuit executions.","failureModes":["Invalid gates array format or unsupported gate types returns an error","Qubit count mismatch with gate operands causes circuit validation failure","Payment not received or insufficient USDC causes 402 rejection before execution","Too many shots or too many qubits may exceed compute limits and return a resource error","Malformed JSON body returns 400 bad request"],"whenToPreferThis":"Choose this endpoint when you need a quick, pay-per-use quantum circuit simulation with no account setup, no API keys, and no KYC — ideal for autonomous agents or developers who want to prototype quantum algorithms or generate quantum-random outputs cheaply and permissionlessly using USDC micropayments on Base, Polygon, or Solana.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T12:42:38.413Z","isFirstParty":false}