What
The plugin marketplace commands can now print their result in JSON, a structured format that other programs can read. With --json, a command prints one machine-readable result line as the last line of its output. Exit codes, the numbers a command returns to say whether it succeeded, stay the same as before.
claude plugin marketplace addgains--json. Its result is labelledcommand: "marketplace-add".claude plugin marketplace removegains--json. Its result is labelledmarketplace-remove.claude plugin marketplace updategains--json, but only together with a marketplace name. Without one it says "--json needs a marketplace name, for example: claude plugin marketplace update --json".
Each result includes an outcome and a failureCode. Before this release these commands printed plain text only. Other commands may also have gained --json, but that was not confirmed.
Why
Scripts and automation can now add, remove and update plugin marketplaces and read the outcome reliably, instead of parsing text meant for people.
Names in the bundle--json
--json
Plugin commands reference modified, high confidence
| `--data-size [plugin]` | Measure each installed plugin's [saved data directory](#what-an-uninstall-deletes-and-keeps), or only the named plugin's, given as `name@marketplace`. Has no effect without `--json`. If the name has no install re…see the edit
--json
Manage sessions modified, high confidence
* Flags that read the output, such as `--output-format json` or `--json-schema`see the edit
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Other commands may also have gained `--json`.
Anthropic's documentation agrees
--json on Plugin commands reference