Description

With Docker 29.0.0. the key "ApiVersion" changed to APIVersion in the Server block, which breaks client that rely on the output of docker version --format '{{json .}}'.

The discussion in https://forums.docker.com/t/breaking-key-change-in-docker-cli-version-response/150390 made me raise this issue.

Note: The Docker v29 api is not affected by the changed key name.

Reproduce

1. docker version --format '{{json .}}' | jq
   {
   "Client": {
   "Platform": {
   "Name": "Docker Engine - Community"
   },
   "Version": "29.0.0",
   "ApiVersion": "1.44",
   "DefaultAPIVersion": "1.52",
   "GitCommit": "3d4129b",
   "GoVersion": "go1.25.4",
   "Os": "linux",
   "Arch": "amd64",
   "BuildTime": "Mon Nov 10 21:46:31 2025",
   "Context": "default"
   },
   "Server": {
   "Platform": {
   "Name": "Docker Engine - Community"
   },
   "Version": "29.0.0",
   "APIVersion": "1.52",
   "MinAPIVersion": "1.44",
   "Os": "linux",
   "Arch": "amd64",
   "Experimental": false,
   "Components": [
   {
   "Name": "Engine",
   "Version": "29.0.0",
   "Details": {
   "ApiVersion": "1.52",
   "Arch": "amd64",
   "BuildTime": "Mon Nov 10 21:46:31 2025",
   "Experimental": "false",
   "GitCommit": "d105562",
   "GoVersion": "go1.25.4",
   "KernelVersion": "6.8.0-71-generic",
   "MinAPIVersion": "1.44",
   "Os": "linux"
   }
   }
   ...
   }

Expected behavior

Instead of "APIVersion" the key "ApiVersion" is used in the "Server" block, like with previous versions.

docker version

Client: Docker Engine - Community
 Version:           29.0.0
 API version:       1.52
 Go version:        go1.25.4
 Git commit:        3d4129b
 Built:             Mon Nov 10 21:46:31 2025
 OS/Arch:           linux/amd64
 Context:           default

Server: Docker Engine - Community
 Engine:
  Version:          29.0.0
  API version:      1.52 (minimum version 1.44)
  Go version:       go1.25.4
  Git commit:       d105562
  Built:            Mon Nov 10 21:46:31 2025
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          v2.1.5
  GitCommit:        fcd43222d6b07379a4be9786bda52438f0dd16a1
 runc:
  Version:          1.3.3
  GitCommit:        v1.3.3-0-gd842d771
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

docker info

not relevant

Additional Info

No response