Comma-separated --id filters silently return zero rows on event, request and transformation list

[leggetter]

Summary

Filter flags documented as accepting a comma-separated list return zero rows when given one, with no error and exit 0. Each ID works individually.

Reproduce

hookdeck gateway event list --id evt_A         → 1 row
hookdeck gateway event list --id evt_B         → 1 row
hookdeck gateway event list --id evt_A,evt_B   → 0 rows, exit 0, no error

Reproduces on gateway event list, gateway request list and gateway transformation list.

The help text explicitly advertises the form: "Filter by event ID(s) (comma-separated)".

Likely cause

The raw comma-joined string appears to be sent as a single scalar id query parameter rather than array-encoded, so the API matches nothing.

Scope

Pre-existing, not a regression. Verified identical on fbb924a and the merged branch, on all three commands.

Why it matters

Silent empty result with exit 0 is the failure shape this release has been fixing elsewhere: the command answers a different question than the one asked and gives no indication. A script filtering by a list of IDs gets "no results" rather than an error, which reads as "these events don't exist".

Related

• Numeric filters cannot express comparisons: no way to send events_count[gte] from CLI or MCP #365 — numeric filters cannot express comparisons (adjacent: filter encoding, different mechanism)
• gateway metrics accepts filters the endpoint ignores, returning unfiltered totals as if filtered #382 — metrics accepting filters the endpoint ignores (same silent-wrong-answer shape)

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Filed by Claude on Phil's behalf, from release-candidate regression testing.