# TaxJar

**Canonical:** https://apis.io/providers/taxjar/  
**Website:** https://www.taxjar.com  
**APIs profiled:** 9

TaxJar is a sales tax automation platform, now a Stripe company, providing APIs for real-time sales tax calculations, rooftop-level rate lookups, transaction recording, and automated filing across US states and international jurisdictions. The platform supports e-commerce businesses of all sizes with sub-20ms response times, 99.999% historical uptime, and AI-powered product tax classification. TaxJar handles nexus tracking, exemption certificate management, and AutoFile returns so merchants can stay compliant without manual effort. Official client libraries are available for Ruby, Python, PHP, Node.js, C#/.NET, Java, and Go.

## Kin Score — 54.4 / 100 (strong)

Scored 2026-08-25 under rubric 0.14.0. Trend: flat (+0.0 from 54.4).

| Facet | Score |
|---|---|
| Discoverability | 74.1 |
| Contract Quality | 74.6 |
| Governance | 25.0 |
| Contract Governance | 25.0 |
| Operational Transparency | 39.5 |
| Developer Ergonomics | 40.5 |
| Commercial Clarity | 60.5 |
| Access Clarity | 60.5 |

## Agent readiness — 24.0 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | documented |
| MCP Server | no |
| Auth Clarity | bearer |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | partial |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## Access

Paid · Self-serve signup — onboarding: self-serve, pricing: paid, trial: no (confidence: high).

## APIs (9)

- **TaxJar Categories API** — Product tax categories
- **TaxJar Customers API** — Customer exemption management
- **TaxJar Nexus API** — Nexus region tracking
- **TaxJar Rates API** — Sales tax rate lookups
- **TaxJar Summary Rates API** — Summarized sales tax rates by region
- **TaxJar Taxes API** — Sales tax calculation
- **TaxJar Transactions - Orders API** — Order transaction management
- **TaxJar Transactions - Refunds API** — Refund transaction management
- **TaxJar Validations API** — Address and VAT validation

## Agentic access (1)

- **Taxjar Agentic Access** — 22 operations · 11 acting

## Security (3)

- **Taxjar Authentication** — http · 1 scheme
- **Taxjar Domain Security** — TLSv1.3 · HSTS · DMARC
- **Taxjar Trust Center** — SOC 2, GDPR

## Plans (1)

- **Taxjar Plans Pricing**

## Tags

Sales Tax, Tax Compliance, E-Commerce, Tax Calculation, Tax Automation, Stripe, Fintech

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/taxjar/). Scores are computed from the provider's own public artifacts under a published rubric.