DRIK-API LICENSE
Drik Panchanga API License
Version 1.0
Copyright © 2026 Acharya Rajesh Benjwal / Tantrakulam (Prithvi Foundation Trust)
LICENSE.txt · Sūrya-siddhānta license
These terms govern access to and use of the Drik Panchanga Engine, its HTTP API, compiled forms, documentation, key issuance, and related operator materials (together, the “Software”).
The ancient astronomical siddhānta texts, public-domain astronomical facts, and mathematical concepts are not claimed as proprietary. What is protected is the Licensor’s source code, implementation, API, databases, original tables, engineering, documentation, branding, and related materials.
1. Definitions
Licensor means Acharya Rajesh Benjwal / Tantrakulam (Prithvi Foundation Trust).
Licensee means the person or organisation that uses the Software or API under a valid API key or written licence.
API means the HTTP JSON/HTML interfaces of the Software, including /v1/panchanga, /v1/panchanga-kala, and related routes.
Commercial Use means any use that is revenue-generating, paid, subscription-based, advertising-supported, sponsored, business, client-facing, or that forms part of a commercial app, website, SaaS, temple or consultation product, horoscope product, or other commercial service — whether the API is exposed to end users or hidden in a backend. An otherwise “free” product funded by advertising, sponsorship, or lead-generation is Commercial Use.
Non-Commercial Use means personal, educational, academic-research, or other non-commercial open projects that are not Commercial Use as defined above.
Free Basic API means the basic plan: limited quota, basic pañcāṅga and basic planetary positions, with mandatory attribution.
Developer and Pro mean keyed non-commercial access to the full engine (dev/test or high-volume research). They do not authorise Commercial Use.
Commercial License means a paid annual Drik-API commercial grant (commercial or enterprise plan, or a written agreement).
2. Ownership and Intellectual Property
The Software, API implementation, algorithms as implemented, source code, compiled binaries, calculation tables, proprietary constants, documentation, and related materials remain the property of the Licensor.
Nothing in this licence transfers copyright in the Software. Traditional siddhānta texts themselves, and uncopyrightable facts of astronomy, are not asserted as the Licensor’s exclusive literary property.
3. Free Basic API License
Subject to these terms, the Licensor grants a worldwide, non-exclusive, non-transferable, revocable licence to use the Free Basic API for Non-Commercial Use only.
Default quota (may be changed by the Licensor): 1,000 API requests per calendar month, with a per-minute burst cap.
Included: tithi, nakṣatra, yoga, karaṇa, vāra, sunrise/sunset, and basic planetary positions (spaṣṭa: body, rāśi, degrees, nakṣatra, gati).
Not included: kundali, muhūrta, saṅkrānti detail, historical/kala endpoints, yearly bulk print, eclipse modules, Drik diagnostic traces, or commercial production use.
4. Permitted Non-Commercial Use
Non-commercial researchers may use the Basic API for academic research, publications, and scholarly analysis, provided that API access limits and attribution requirements are respected.
Personal study, classroom use, and non-commercial open projects are permitted under the Free Basic API on the same conditions.
5. Prohibited Use
Licensee may not, without a separate written agreement:
- use the Free Basic API for Commercial Use;
- resell, sublicense, redistribute, mirror, clone, expose, or provide the API as an independent competing API service;
- extract bulk API results for the purpose of creating a competing astronomical or pañcāṅga database;
- remove or obscure required attribution on Free / Developer / Pro outputs;
- share, publish, or leak API keys;
- circumvent rate limits, licence checks, or access controls.
6. Commercial Use
Commercial Use is not granted by the Free Basic API. If Licensee (or a product Licensee operates) is Commercial Use, a valid Commercial License is required — even if the API is not resold and is only used internally as a calculation backend.
7. Commercial License Requirement
Non-Commercial Use is permitted under the Free Basic API Terms. Commercial Use requires a valid Commercial License.
A Commercial License is typically issued annually and may record application ID, company, domain, package ID, API key, monthly quota, and expiry.
Developer and Pro keys are technical access tiers. They do not, by themselves, authorise production Commercial Use. Production apps, websites, and SaaS require the Commercial (or Enterprise) licence.
8. API Keys and Rate Limits
Access is keyed. Typical published quotas are API credits, not a promise of unlimited CPU (operator may adjust; see also pricing):
| Plan | Typical credits / month | List price | Commercial production |
|---|---|---|---|
| Free Basic | 1,000 | ₹0 | No |
| Developer | 10,000 | ₹499 / year | No (dev/test only) |
| Pro | 100,000 | ₹1,499 / year | No (high-volume non-commercial) |
| Commercial | 1,000,000 | ₹4,999 / year | Yes (annual) |
| Enterprise / Admin | Unlimited | from ₹21,000 / year | Yes (written terms / SLA) |
Commercial’s 1,000,000 figure means standard API credits per month, subject to reasonable-use limits and endpoint-specific computational weights. A light panchanga slice costs one credit; a full kundali, Shadbala, Ashtakavarga, Jaimini, or matching call costs more, as published on the pricing page. The kundali book PDF, mobile kundali pack, and multi-day /v1/panchanga/range, /v1/panchanga-kala, and /v1/panchanga/month are Enterprise-only (from ₹21,000 / year, unlimited credits). The Licensor may throttle or suspend a key that uses the service as a substitute for unlimited dedicated compute.
The running service enforces plan, scope, credits, and rate limits. Exceeding a quota may yield HTTP 429. Keys may be suspended for breach.
9. Redistribution
Licensee may not resell, sublicense, redistribute, mirror, clone, expose, or provide the API as an independent competing API service without a separate written agreement.
10. Bulk Data Extraction
Calculated facts in a single ordinary response are not claimed as copyrighted literature. Licensee nevertheless agrees not to bulk-extract, harvest, or cache API results, proprietary metadata, diagnostic information, or derived datasets in order to build a competing astronomical or pañcāṅga database or service.
11. Reverse Engineering
Licensee shall not reverse engineer, decompile, or attempt to extract source, keys, or unpublished constants from hosted binaries or the API except to the extent that mandatory law cannot be waived.
12. Derivative Works
Non-commercial wrappers that call the API and preserve attribution are allowed under the Free Basic terms. Shipping a competing engine, cloned API, or commercially distributed derivative of the source requires a written licence.
13. Attribution
Free Basic, Developer, and Pro: Licensee must display, in documentation or UI reasonably visible to end users:
Calculations by Drik Panchanga Engine
or
Powered by Drik Panchanga Engine
Commercial License: attribution is optional by default (white-label permitted) unless the written grant says otherwise.
14. Enterprise Licensing
Enterprise starts at ₹21,000 / year with unlimited credits (SLA, support, named domains, kundali book PDF / pack) as set out in a written agreement with the Licensor.
15. Fees and Renewal
Published Developer, Pro, and Commercial list prices are annual and expire unless renewed. Enterprise is quoted. Fees are as published on the pricing page, or as written in the grant. Non-payment may suspend the key.
16. Suspension and Termination
The Licensor may suspend or terminate a key for breach, abuse, non-payment, or legal risk. On termination, Licensee must stop calling the API. Sections on ownership, disclaimer, liability, and bulk-extraction survive.
17. Disclaimer of Accuracy
The Licensor does not warrant that calculations will exactly match Sūrya-siddhānta, Swiss Ephemeris, NASA/JPL ephemerides, any particular traditional pañcāṅga, or any regional religious calendar. Results follow this engine’s Drik implementation, conventions, and place/time inputs. Empty moment = sunrise (रिक्तः क्षणः = सूर्योदयः).
18. No Warranty
The Software and astronomical calculations are provided “AS IS” and “AS AVAILABLE”, without warranties of accuracy, fitness for a particular purpose, uninterrupted availability, or error-free operation.
19. Limitation of Liability
To the maximum extent permitted by law, the Licensor is not liable for indirect, incidental, special, consequential, or punitive damages, or lost profits, arising from use of the Software or API.
20. Indemnification
Commercial Licensees shall indemnify the Licensor against claims arising from Licensee’s product, marketing, ritual advice, or combination of the API with third-party data, except to the extent caused by the Licensor’s wilful misconduct.
21. Third-Party Software
The Software may bundle or call third-party components (for example ephemeris bindings and chart-drawing libraries) under their own licences. Those licences continue to apply to those components.
22. Changes to License
The Licensor may publish a new version of these terms. Continued use after notice constitutes acceptance of the version then posted, except that a paid annual Commercial License follows the version in force at purchase unless the written grant says otherwise.
23. Governing Law
These terms are governed by the laws of India. Courts at Dehradun, Uttarakhand, have exclusive jurisdiction, subject to mandatory consumer protections where they apply.
24. Contact
Tantrakulam / Prithvi Foundation Trust
138, THDC Colony Banjarawala, Dehradun, India
info@tantragurukul.org
https://panchang.tantragurukul.org/
सूत्रम्: v1/panchanga · विस्तृतकालः: v1/panchanga-kala · पञ्चाङ्ग पृष्ठ