`--format json` full-project fetch over-fetches fields and can exceed gateway request-time limits

[ryancheley]

Summary

yt issues list --format json (and --all) requests a heavy field set by default —
dominated by customFields(...) expanded for every issue — producing large responses that,
on a constrained/remote network, make a full-project fetch exceed a gateway's per-request time
limit and get killed (the process is SIGTERM'd, exit 15). There is currently no working way
to trim the field set for JSON output, because --profile is broken (#726).

Evidence (v0.24.2, 178-issue project)

yt issues list --project-id NGDEV --format json --top 178:

fields	response	time (local, fast net)
default	268,100 bytes (~1.5 KB/issue)	1.84s
explicit --fields idReadable,summary,description,created,customFields(name,value(name))	200,831 bytes	0.65s
--fields idReadable,summary,description,created (no customFields)	much smaller	—

The default field set (from youtrack_cli/services/issues.py, ~line 141):

id,summary,description,state,priority,type,customFields(id,name,value(login,fullName,name))

customFields(...) returns every custom field for every issue, which is the bulk of
the payload. Scaled up: a 2,000-issue project ≈ 3 MB in one response. Over a remote link with,
say, a ~20s gateway timeout, the request never completes and is killed — the caller sees 0
issues, no error.

Observed request-time curve (against a real gated instance)

--top	wall time
100	~6s
250	~8s
500	~22s → killed (exit 15)
--all / default (whole project)	killed

So the per-request payload/time grows past the gateway ceiling well before the whole project
is fetched.

Suggestions (in priority order)

1. Fix --profile (--profile is broken: profile name is passed to the REST fields param instead of being resolved #726) so --profile minimal/standard actually shrink the payload —
   the primary lever for JSON perf.
2. Add a JSON-friendly lean profile (e.g. compact) that includes summary/description
   but omits the full customFields expansion, for callers that don't need every custom field.
3. Consider a leaner default fields for --format json, or at least document that large
   JSON fetches should pass --fields/--profile to stay under network limits.
4. Request-time resilience for --all: smaller default page size and/or streaming/NDJSON
   output so a large project is fetched as many small responses rather than one big one that a
   gateway can kill.

Context

Hit while building a tool that fetches whole projects as JSON over a remote network. We worked
around it by chunking (--top + a created-date cursor) so each request is bounded, but the
underlying payload weight and the broken --profile are the real levers, especially for JSON.

[github-actions]

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GitHub user: ryancheley
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[ryancheley]

Fixed in 0.24.4 (PRs #732, #733, #734).

Three levers, all shipped:

1. --profile fixed (--profile is broken: profile name is passed to the REST fields param instead of being resolved #726) — minimal/standard now actually trim the payload.
2. New compact profile — core fields + description but no customFields expansion (the bulk of large payloads), for lean --format json.
3. Bounded-page fetching — list/search no longer issue a single unbounded request. Results are fetched in pages of --page-size (default 100), so each request stays small (~6s) and a whole-project fetch completes instead of hitting a gateway's per-request timeout and getting killed.
4. --format ndjson — streams one JSON issue per line as pages arrive, so large fetches use bounded memory and can be piped/processed incrementally (e.g. | jq).

Released: https://pypi.org/project/youtrack-cli/0.24.4/