GPLv3's source duty turns on conveying, not on running

The workload

Shipping a modified GPL-licensed dependency at all, in any distributed form, creates a specific obligation the license text states in section 0's definitions. Verified: 'convey' means propagation 'that enables other parties to make or receive copies,' and conveying a covered work in object code form requires, per section 6, also conveying 'the machine-readable Corresponding Source under the terms of this License.' The workload is preparing that Corresponding Source and a compliant way to transfer it, whenever the modified work is actually conveyed to someone else, not merely run.

What the documents show

Verified: section 0 draws the line precisely: 'to propagate' a work means anything that would make someone liable for infringement without permission, while 'to convey' is the narrower subset that lets others make or receive copies; the text adds that 'mere interaction with a user through a computer network, with no transfer of a copy, is not conveying.' That is the exact point where GPLv3 differs from the AGPL's network-use trigger already documented in this batch: GPL's duty depends on handing over a copy, not on remote interaction. Verified: section 6 lists compliant ways to satisfy the source-offer duty when conveying object code, including a written offer 'valid for at least three years' to provide source on a physical medium. Verified: the FSF's own GPL FAQ confirms an organization 'can make a modified version and use it internally without ever releasing it outside the organization,' and only public release triggers the duty to make source available.

The operating cost

The license names no fee for the source itself, only the mechanics of offering it; per the text, a distributor 'may charge any price or no price' for a conveyed copy, but the Corresponding Source must still be available under the license's terms. Estimated: the cost is engineering time to package and maintain a source offer whenever the modified tool is distributed outside the company, which for a one-person SaaS business running internal tooling often stays at zero, because nothing is conveyed.

The stop condition

Per the FAQ, the obligation simply does not start for internal, unreleased modifications; it starts only at the moment of conveying, and stops mattering again once the modified copies stop being distributed to new parties. A command-line GPL tool run internally to build or operate a product, without distributing a modified copy of that tool itself, does not trigger source disclosure under this text; the disclosure duty is conditioned on distribution, not on internal use, and this entry does not extend the clause past what section 0 states.

• Is the GPL-licensed tool in question being conveyed to anyone outside the organization, in modified or unmodified form?
• If it is conveyed, which of section 6's compliant methods will carry the Corresponding Source?
• Does the workload change at all if the tool is only run internally and never distributed?

GPLv3's copyleft condition is triggered by an act, conveying, not by a category of software. Confusing 'GPL-licensed' with 'always obligates disclosure' skips the distribution test the license text itself makes central.