OnlyTax

The description states:

• OnlyTax is a TypeScript-based application built with Express.js, Playwright, and PostgreSQL.
• It processes monthly sales and purchases into a VAT close package.
• It normalizes purchase descriptions into stable product identities before applying activity and VAT rules.
• It stops processing when there’s an unknown or ambiguous product, asking the client for factual input instead of guessing.
• It includes five accountant exports (JSON, HTML, audit summary, manifest, reconciliation report).
• It seals packages only after reconciliation across document manifest, ledger, and declaration draft.

Inference The system is a deterministic workflow engine that enforces traceability in tax processing, not just a categorization tool. It is designed to be inspectable by accountants and does not silently infer missing data.

The description states:

• The core positioning is: “Calculating VAT is easy. Defending every number is not.”
• The product is built around the principle: “evidence before authority.”
• It aims to make tax close processes explainable and defensible, especially in Paraguay where Law No. 6380/2019 ties deductions to underlying transaction evidence.

Inference The positioning evolved from a simple categorization tool into a full workflow engine focused on auditability and compliance with local tax law. It is not positioned as a general-purpose accounting tool but as a specialized solution for VAT close in Paraguay.

The description states:

• The primary user is an accountant working in Paraguay.
• The system supports the accountant by providing a package that can be inspected, explained, and defended.
• Clients provide factual information to resolve ambiguous or missing business facts.

Inference The ICP appears to be accountants or tax professionals in Paraguay who are required to defend VAT deductions under Law No. 6380/2019. The client is not the end-user but a business entity providing factual inputs.

Not evidenced.

The description states:

• Built with TypeScript, Express.js, PostgreSQL, Playwright, GPT-5.6 Sol in Codex.
• Uses a server-rendered UI (SSR) and automation packages for normalization, categorization, VAT calculation, and declaration compilation.
• Includes deterministic behavior, fail-closed package sealing, and adversarial testing.
• The demo uses synthetic data and is runnable without external services or credentials.

Inference The technical stack suggests a modern, typed, and testable application. The use of GPT in design and testing indicates an engineering-driven approach to problem-solving. The deterministic behavior and fail-closed logic suggest a strong emphasis on correctness and auditability.

Not evidenced.

Not evidenced.

• Prototype nature: The product is described as a hackathon demo with synthetic data and no real-world integration.
• No external validation: There is no evidence of feedback from actual accountants or tax professionals.
• Limited scope: It only supports one country (Paraguay) and one specific law (Law No. 6380/2019).
• Dependency on GPT for design: While useful, reliance on AI for architecture and testing may not scale without human oversight.
• No production deployment or monitoring: The next steps include “production tenant deployment,” but this is not yet realized.

1. What specific feedback have you received from Paraguayan accountants, if any?
2. How does OnlyTax handle integration with existing accounting systems or tax portals in Paraguay?
3. Is there a plan to expand beyond Paraguay’s VAT rules and into other jurisdictions?
4. How are the VAT rules and activity mappings validated or calibrated?
5. What is the current status of the “authorized document-ingestion connectors” and filing integrations?