Cross-tenant PUBLIC browse/search over promoted memories, sessions and collections. Empty q = ranked browse. kind/tag are comma-separated filters; sort ∈ {relevance, imports, rating, recent}. Only promoted-latest items appear (private collections excluded) — the same public set as the mirror.

topic=tag:<slug> / topic=category:<slug> (#999) keeps the listings of one topic page (collector/topics.py: the slug, so every spelling of a tag counts) and adds topic to the response: {kind, slug, name, count, indexable} — the same facts the server-rendered /marketplace/<kind>/<slug> page is built from (collector/topic_pages.py). It does not combine with access (400): that lists the viewer's own items, unfiltered.

access=accessible|acquired lists the VIEWER's items instead (everything they can load, or only what they didn't author), newest first, filtered before paging so nothing older than a page is lost. q/tag/sort don't apply there; an anonymous viewer gets an empty list.

harness=<id>[,<id>…] (#867 PR 8, additive) keeps the listings recorded with those harnesses (claude-code, codex-cli, gemini-cli, opencode, grok-build, unknown; the aliases claude, codex, gemini, grok work too). An unregistered value is a 400. With the harness flag on, every row carries labels and facets.harness counts listings per harness (collector/harness_labels.py).