Output shaping

Google APIs often return large JSON objects. gum keeps operation discovery and responses smaller with catalog search, field masks, compact output formats, and expression profiles.

Formats

Common CLI paths accept --output:

bash

gum read gmail.users.messages.list \
  --args '{"userId":"me","maxResults":5}' \
  --output json

Supported output modes vary by command. Use the generated command page for the specific flag set.

Field masks

When an operation supports a Google partial-response fields parameter, pass the narrow fields needed by the task:

bash

gum read drive.files.list \
  --args '{"pageSize":10,"fields":"files(id,name,mimeType),nextPageToken"}' \
  --output json

This reduces upstream payload size before gum applies any local shaping.

Gain replay

gum gain --fixture-replay runs the deterministic local fixture replay used by the current checkout. It is a regression tool, not a billing promise.

bash

gum gain --fixture-replay --format toon
gum gain --fixture-replay --format json

Report gain numbers with the command, format, binary version, and fixture set that produced them.