Tau x402 Cage — Dual License
Copyright (c) 2026 IDNI (Ohad Asor). All rights reserved.

SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-IDNI-Commercial

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  DUAL-LICENSE NOTICE
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This software is dual-licensed. You may choose one of the two licenses below,
according to your use.

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  1. GNU General Public License v3.0 or later (GPL-3.0-or-later)
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This software is free software: you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, either version 3 of the License, or (at your option) any later
version.

This software is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with
this software. If not, see <https://www.gnu.org/licenses/gpl-3.0.txt>.

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  2. IDNI Commercial License
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Organizations that cannot or prefer not to adopt the GPL-3.0-or-later terms
(for example: proprietary in-house deployments, enterprise self-host, hosted
SaaS resale, or closed-source integrations) may obtain a commercial license
from IDNI on separate written terms.

Contact:  services@idni.org
Pricing:  see docs/pricing.md

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  PATENT NOTICE
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The decision procedure implemented in this software is covered by
United States Patent No. 12,254,082 (granted 2026-03-18, expires 2044-07-17),
assigned to IDNI, inventor Ohad Asor. Public prior art: arXiv:2407.06214
("Guarded Successor: A Novel Temporal Logic").

Royalty-free patent grant:
  IDNI grants a non-exclusive, worldwide, royalty-free license to the claims
  of US Patent 12,254,082 for the purpose of creating, using, and distributing
  implementations of the "Formal Policy Semantics for HTTP 402 Agentic Payments"
  RFC (see docs/rfc/), provided that such implementations:
    (a) are licensed under GPL-3.0-or-later or a compatible OSI-approved
        open-source license;
    (b) conform to the normative (MUST-level) requirements of the RFC as
        measured by the published TTI conformance battery; and
    (c) preserve this NOTICE in source distributions.

Implementations that do not meet conditions (a)-(c) above require a commercial
license (see section 2 above). This grant is revocable only for patent
aggression as defined in standard open-invention-network terms.

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  TRADEMARKS
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"Tau Language", "tau-lang", "tau-x402-cage", and "IDNI" are trademarks of IDNI.
The GPL license does not grant trademark rights.

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  NO WARRANTY
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THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR A PARTICULAR PURPOSE, ARE DISCLAIMED. IN NO EVENT SHALL IDNI OR
ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE.

For a human-readable summary of GPL-3.0-or-later obligations see:
  https://www.gnu.org/licenses/quick-guide-gplv3.html
