Bring Five Hard Transactions — v1.0.0 PURPOSE Inspect difficult sales-tax behaviors before choosing a calculation engine or compliance workflow. These are reference examples, not a vendor ranking, a nationwide benchmark or a promise of future buyer outcomes. WHAT ACTUALLY RAN The API examples executed ItmsApiService against a newly created local in-memory SQLite database with synthetic organization/customer/certificate records. They were service calls, not hosted HTTP requests. The source hashes and configuration are in manifest.json. The isolated Virginia rate snapshot is 5.3% for ordinary general-retail activity in Harrisonburg, dated July 2026. Address handling uses fixture/regex precision, not a purchased geocoder or verified rooftop result. The address example executed the real Illinois index builder and resolver over nine unchanged rows from the repository's official-derived July 2026 sample. Two exact addresses in ZIP 60084 returned 8.25% and 7.25% and different location codes. This proves those component lookups only. It does not test the full source file, live geocoding, legal sourcing or product taxability. These historical rates must not be used as current checkout quotes. The certificate fixture links an exempt synthetic customer to an active certificate whose effective-to date is July 26, 2026. It exercises the supported linked-certificate bridge: the valid date produces $0 tax; the explicit expired-certificate request is refused. The artificial effective-to boundary is not a claim that Virginia resale certificates universally expire. Full identity matching and document review are not established by this fixture. The responsibility example executes the actual responsibility service with explicit synthetic channel facts. Those inputs stipulate facilitator remittance; a marketplace name alone never proves it. The unknown row retains $2.65 unresolved responsibility. The Virginia sample executes build_st1_from_package and validate_st1_file with the published synthetic canonical snapshot. Its source-row decisions, product identity, locality and exemption review are explicit fixture inputs. It does not demonstrate customer ingestion, human approval, a registered account or state acceptance. The unresolved variant refuses to generate a file. Negative/refund activity is not included in this writer's supported scope; the partial-refund API example is separate. READ THE PACK OFFLINE 1. Start with manifest.json (case explanations, source links, configuration and hashes). 2. Open api-executions.json, address-executions.json and responsibility-executions.json. 3. Compare sales-ledger.csv, package-input.json and SYNTHETIC-DO-NOT-FILE-ST1.txt. 4. Read package-execution.json, including excluded fields and the blocked variant. 5. Run: python verify.py This verifies file integrity and sample reconciliation. It does NOT run the engine. RERUN THE PUBLIC ADDRESS AND PACKAGE EXAMPLES Run python reproduce.py to request fresh executions from: https://prophit.ai/api/public-evaluation/five-hard-transactions/v1/reproduce No account, key or private repository access is required. The endpoint accepts no visitor inputs and runs the actual Illinois index builder/resolver and Virginia package writer/validator on this version's published inputs. It returns results, source hashes and an execution time. reproduce.py compares the rates, location codes and exact ST-1 bytes with the archived pack. A mismatch is reported, never hidden. This repeats those two components, not the full tax engine or a real filing. REPEAT THE API CASES IN YOUR OWN AUTHORIZED SANDBOX Read https://prophit.ai/api-access/environments and /api-access/coverage first. Request scoped organization sandbox access through the evaluation form if needed. Existing workspace users may sign in at https://prophit.ai/login. The campaign does not grant a free service entitlement, API credential, subscription or filing permission. Set ITMS_SANDBOX_KEY locally to your itms_test_ key. Never paste it into a public URL, worksheet, issue or assistant transcript. The script verifies /api/v1/context reports an organization sandbox before any transaction mutation. It reads configuration and coverage, then creates one synthetic sale and a partial refund. Use a dedicated test location with authorized Virginia nexus configuration. It leaves its sandbox records for inspection, using a unique code per run. It never touches production credentials, filing, payment, refunds of real charges or certificate activation. python replay.py # help; no network python replay.py --run --out my-run.json # runs the sandbox sequence Optional --customer-code and --certificate-code must name EXISTING reviewed synthetic records in your sandbox whose validity matches the two published dates. The script never creates or approves exemption evidence. Without these options the certificate case is recorded as skipped. The public reference database is not provisioned by this script. Your tenant, active content and configuration can produce different results; record them as differences or unavailable outcomes, not automatic failures or passes. For repeatable source-level regeneration, the implementation is scripts/seo/build_hard_transactions_pack.py at the source_commit and module hashes in manifest.json. That internal repository is not required for public HTTP replay; access to that source is required to recreate its isolated reference database exactly. EQUAL-INPUT EVALUATION Use switching-worksheet.csv for five representative cases. Freeze dates, jurisdiction, product identity, nexus, certificate scope, channel facts, rounding and engine versions. Use another vendor only through authorized access. Keep its output blank if unavailable. A handpicked example is not an industry-wide ranking. A request, download or sample inspection is not a qualified sales opportunity or paid activation. PRIMARY AUTHORITIES Illinois address-specific tax-rate files: https://tax.illinois.gov/research/taxrates.html Virginia rates/localities: https://www.tax.virginia.gov/sales-tax-rate-and-locality-code-lookup Virginia exemptions: https://www.tax.virginia.gov/sales-tax-exemptions Virginia marketplace obligations: https://www.tax.virginia.gov/remote-sellers-marketplace-facilitators-economic-nexus Virginia ST-1 layout: https://www.tax.virginia.gov/sites/default/files/inline-files/specifications-for-web-upload-server-to-server-processing.pdf Review date: 2026-10-21. Effective sample transaction date: 2026-07-26. PUBLICATION / REUSE The replay and verification scripts and synthetic business examples may be reused, modified and redistributed under the MIT terms in LICENSE.txt. Illinois address rows are an attributed extract of official data; no claim of ownership or exclusive license is made over government material. Primary-source publications retain their own terms. No third-party endorsement or affiliation is implied.