Opening this to settle a licensing question early rather than at the moment it becomes blocking. Nothing changes today, and no action is required from anyone unless they want to give consent now.
What this is about
cA2A has been proposed as an A2A extension (a2aproject/A2A#2079). A2A's extension governance requires Apache 2.0 for extensions that reach official tier. That tier also requires adoption evidence cA2A does not have yet, so the licence is not on the critical path — but it is cheaper to ask while everyone is reachable than to chase consent later.
Why it cannot be done unilaterally
cA2A is MIT and uses DCO with no CLA (CONTRIBUTING.md: "No CLA required"). Under DCO, contributors license their work under the project's existing licence. The project does not acquire the right to relicense their contributions, so a maintainer cannot flip MIT to Apache 2.0 on their own. That is a deliberate property of DCO, not an oversight.
Two external contributors hold copyright in the current tree:
The ask
If you are happy for your contributions to be relicensed, please comment on this issue with something like:
I consent to my contributions to agentrust-io/ca2a being relicensed under Apache License 2.0.
That is all. No paperwork, no CLA, and it is not retroactive to anything else you have written.
If you would rather not, that is a perfectly acceptable answer and it is genuinely useful to know: the fallback is to keep the project MIT, or to ship under Apache 2.0 while preserving the MIT notice covering prior contributions, which is legally sound but messier and wants a lawyer's eye rather than a maintainer's. Saying no does not remove your code or affect your contributions in any way.
Sequencing
- Now: this thread, open-ended. cA2A stays MIT.
- If and when A2A official graduation is actually in reach: relicense with whatever consent has accumulated, or take the notice-preserving route for anything outstanding.
/cc @Susanpdl @carloshvp
Opening this to settle a licensing question early rather than at the moment it becomes blocking. Nothing changes today, and no action is required from anyone unless they want to give consent now.
What this is about
cA2A has been proposed as an A2A extension (a2aproject/A2A#2079). A2A's extension governance requires Apache 2.0 for extensions that reach official tier. That tier also requires adoption evidence cA2A does not have yet, so the licence is not on the critical path — but it is cheaper to ask while everyone is reachable than to chase consent later.
Why it cannot be done unilaterally
cA2A is MIT and uses DCO with no CLA (
CONTRIBUTING.md: "No CLA required"). Under DCO, contributors license their work under the project's existing licence. The project does not acquire the right to relicense their contributions, so a maintainer cannot flip MIT to Apache 2.0 on their own. That is a deliberate property of DCO, not an oversight.Two external contributors hold copyright in the current tree:
src/ca2a_runtime/transport/, error registry, transport spec). Substantive, and precisely the code the A2A proposal points at.The ask
If you are happy for your contributions to be relicensed, please comment on this issue with something like:
That is all. No paperwork, no CLA, and it is not retroactive to anything else you have written.
If you would rather not, that is a perfectly acceptable answer and it is genuinely useful to know: the fallback is to keep the project MIT, or to ship under Apache 2.0 while preserving the MIT notice covering prior contributions, which is legally sound but messier and wants a lawyer's eye rather than a maintainer's. Saying no does not remove your code or affect your contributions in any way.
Sequencing
/cc @Susanpdl @carloshvp