The agent-ready payment simulator for fintech integration teams.
Switchbench lets issuers, acquirers, processors, fintechs, and AI coding agents build and validate Visa, Mastercard, and domestic card scheme integrations — scenario by scenario — before scheme certification, partner sandbox queues, or production risk.
Why agent-ready payment testing matters now.
AI coding tools can generate payment integration code faster than teams can safely test it. That creates a new bottleneck: validation. Payment teams need to know:
Did the agent generate a valid ISO 8583 message?
MTI, bitmap, data elements, scheme-specific validation — checked at the protocol level, not stubbed.
Does the integration handle 05, 51, 54, 91, timeout, reversal, and duplicate scenarios?
The hard cases — declines, network unavailability, reversals, duplicates — covered as first-class scenarios.
Did the code break edge-case handling?
Regression-test agent-generated changes against your full scenario pack before they merge.
Can the change be replayed, inspected, and approved?
Every request, response, ISO field, and rule decision captured for review and audit.
Can the evidence be shared with QA, architecture, compliance, or certification teams?
Replayable logs and evidence reports that travel from engineering to certification without a screenshot.
Switchbench is the answer.
A realistic payment network for your team and your agents to test against — before anything reaches Visa, Mastercard, a processor, or production.
Try it before you trust it.
Pick a scenario. Hit Run. See a protocol-accurate response. Same endpoints whether the caller is a human engineer, a CI pipeline, or an AI coding agent.
Humans write. Agents generate. Switchbench validates.
One controlled execution environment for three users: human engineers, CI/CD pipelines, and AI coding agents.
Point your application, processor, or generated code at Switchbench endpoints.
ISO 8583 over TCP, MQ, or HTTPS. REST and gRPC for higher-level callers. Stable endpoints that humans, CI jobs, and AI coding agents can target the same way.
Select scheme, role, response behaviour, timeout, reversal, HSM operation, or edge case.
Visa, Mastercard, or domestic. Issuer or acquirer role. Approvals, declines, timeouts, reversals, stand-in, partial approvals, and HSM operations — composed into scenario packs.
Capture every request, response, ISO field, and rule decision.
Every scenario outcome is captured for replay, approval, and regression testing — for human review, CI gating, or evidence shared with QA, compliance, and certification.
Your integration — or your AI agent's code — thinks it is talking to a real scheme.
Switchbench speaks payment behaviour, not generic mocks. It gives developers and AI-generated code realistic responses across ISO 8583, scheme rules, HSM operations, timeouts, reversals, and edge cases. Nothing reaches the real card networks, so teams can run risky scenarios safely and repeatedly.
Realistic payment-network behaviour for humans, pipelines, and agents.
Approved is the easy case. The hard case is the decline you didn't plan for, the timeout mid-3DS, the unexpected partial approval, the agent-generated mapping that silently drops a data element. Switchbench covers all of them.
Agent-ready test endpoints.
Stable, documented endpoints that AI coding agents and CI pipelines can call directly for realistic payment tests — no bespoke scaffolding per agent or run.
Programmable payment scenarios.
Control approvals, declines, timeouts, reversals, stand-in behaviour, fraud blocks, partial approvals, and intermittent failures — composed into scenario packs your team and your agents reuse.
ISO 8583 validation.
Inspect MTI, bitmap, data elements, response codes, and scheme-specific validation errors — at the protocol level, so agent-generated mappings are checked, not assumed.
HSM simulation without hardware.
Cloud-hosted PayShield-style simulator behind a REST API. PIN verify, MAC generate, key translation, CVV validation — for testing and development, not production cryptography.
CI/CD and agent workflow support.
GitHub Actions and GitLab CI templates, API-triggered test runs, replayable logs, and test evidence reports — so agent-generated changes get the same gates as human changes.
Audit-ready evidence.
Every scenario run produces a shareable record: request, response, timing, decision path, ISO fields, and result — ready for QA, architecture, compliance, or certification review.
What your agents can safely test.
Concrete examples of agent-generated payment work that can be validated against Switchbench before a human merge, certification submission, or production change. Human approval remains expected for risky payment changes.
Issuer authorisation handling.
Generate issuer authorisation logic and run it against approvals, declines, partial approvals, and stand-in scenarios.
Timeout and reversal behaviour.
Modify timeout handling and validate that 0420 reversals, retries, and idempotency keys behave correctly.
New response-code handling.
Add handling for new DE 39 codes and run regression scenarios over the full existing pack to catch breakage.
ISO 8583 mapping code.
Generate ISO 8583 mapping changes and validate field-level correctness — MTI, bitmap, data elements, scheme variants.
Test cases from requirements.
Build test cases directly from written requirements and run them against realistic scheme behaviour.
Evidence for human review.
Produce replayable evidence reports for human review before merge or certification — the change and its proof, side by side.
Pricing — coming soon.
Early-access customers will get access to agent-ready scenario packs, hosted simulation endpoints, replayable logs, and CI/CD templates. Founder design partners receive a discount on first-year pricing.
Questions your CTO will ask.
Is Switchbench an AI agent?
Can AI coding agents use Switchbench directly?
Does this replace Visa or Mastercard certification?
Is this safe for sensitive payment data?
Is this PCI-DSS compliant?
Does it work with my processor?
What response codes do you support?
00, Do Not Honor 05, Insufficient Funds 51, Expired Card 54, Lost Card 41, Stolen Card 43, Incorrect PIN 55, and every flavor of decline, referral, and partial approval in between. Full list in the docs.
Can I self-host it?
How do I cancel?
Who is building this?
Give your team — and your AI agents — a safe payment network to test against.
Join the early-access waitlist. First design partners get access to agent-ready scenario packs, hosted scheme simulation, CI/CD templates, and replayable evidence reports before general availability. No credit card required to sign up.
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"I built the VisaNet simulator and PayShield HSM simulator that power this because I got tired of waiting weeks for sandbox credentials. Turns out every payment engineer I talked to had the same problem. So I'm packaging it up."