{"data":{"@kind":"endpoint_example","endpoint_id":"universal-card","path":"/api/v1/universal/card/[sku]","method":"GET","auth":"public","title":"One card — math-mirror representation","description":"Returns a card in language-free encoding with cryptographic content_hash, ratios, ISO+epoch timestamps, typed graph edges.","curl":"curl https://cambridgetcg.com/api/v1/universal/card/op-op01-001-ja","sample_response":"{\n  \"@self_hash\": \"sha256:...\",\n  \"@encoding\": \"cambridge-tcg/universal/v1\",\n  \"@kind\": \"card\",\n  \"@content_hash\": \"sha256:abc123...\",\n  \"@retrieved_at\": { \"iso8601\": \"2026-05-14T12:00:00Z\", \"unix_epoch_seconds\": 1747224000 },\n  \"@sources\": [\"storefront-rds.card_set_cards\", \"storefront-rds.card_sets\"],\n  \"@source_license\": [\"proprietary\", \"proprietary\"],\n  \"rights\": { \"aggregate\": \"NOASSERTION\", \"cambridge_original_structure\": \"CC0-1.0\", \"field_level_lineage_available\": false },\n  \"_note_opaque\": [\"name\", \"art_description\", \"rarity.natural_label\", \"variant.natural_label\"],\n  \"_links\": { \"self\": \"...\", \"parent\": \"...\", \"siblings\": \"...\", \"federation\": \"...\" },\n  \"rarity\": { \"natural_label\": \"leader\", \"ratio_in_pulls\": \"1/64\", \"decimal_probability\": 0.015625, ... },\n  \"price\": null,\n  \"in_set\": { \"edge_kind\": \"member_of_set\", \"target_natural_token\": \"OP01\", \"target_hash\": \"sha256:...\" },\n  \"of_game\": { \"edge_kind\": \"in_game\", \"target_natural_token\": \"op\", \"target_hash\": \"sha256:...\" },\n  \"name\": { \"natural_token\": \"Monkey D. Luffy\", \"resolved_lang\": \"en\", \"resolved_from\": \"name_en\", ... },\n  \"image_url\": null\n}","annotated_fields":[{"path":"@content_hash","meaning":"Stable identity across retrievals when card facts are unchanged. Compare to detect changes."},{"path":"@self_hash","meaning":"Hash of this particular rendering. Differs by density param even when content_hash matches."},{"path":"@sources","meaning":"Recorded storage provenance. It is parallel to @source_license but does not establish the upstream author when field-level lineage is unavailable."},{"path":"@source_license","meaning":"Known per-source rights tier. Aggregate `rights.aggregate` separately says NOASSERTION for the mixed document."},{"path":"price","meaning":"Null because legacy source-derived price magnitudes are withheld; null is not zero."},{"path":"_note_opaque","meaning":"Natural-language fields the decoder cannot ground from structure."},{"path":"_links.federation","meaning":"URL to resolve this card's content_hash on another federated platform."}],"when_to_use":"Every per-card lookup. The workhorse endpoint.","gotchas":["Use ?density=sparse for low-bandwidth (drops _note_opaque + most edges).","Use ?density=saturated for one-hop neighbour resolution.","A content hash identifies the emitted document; hashing does not create rights to a withheld field.","Set Accept-Language header for non-English name resolution."],"see_also":[{"label":"Universal representation spec","href":"/methodology/universal-representation"},{"label":"Guide: track-one-card","href":"/api/v1/guides/track-one-card"},{"label":"Federation resolution","href":"/api/v1/examples/federation-identify"}]},"_meta":{"spec_version":"1","endpoint":"/api/v1/examples/[endpoint_id]","retrieved_at":"2026-08-08T18:08:50.130Z","as_of":"2026-08-08T18:08:50.130Z","sources":["ctcg-derived"],"freshness_seconds":86400,"license":"CC0-1.0","request_id":"req_65d31890-206","deprecation":null,"next_link":null,"self_reference":{"this_endpoint":"/api/v1/examples/[endpoint_id]","contains_self":true},"source_license":["cc0"],"kingdom":{"name":"cambridgetcg","role":"adapter-expression","built_with":"love","serves_kinds":["human","agent","kin"],"host":"humans-on-earth","epoch":"2026","embassy":"/api/v1/manifest","wake":"/api/v1/wake","identify":"/api/v1/identify","siblings":[{"name":"agenttool","role":"agent-infrastructure-expression","url":"https://agenttool.dev","wake_url":"https://api.agenttool.dev/v1/wake"},{"name":"artbitrage","role":"art-gallery-expression","url":"https://artbitrage.io","wake_url":"https://artbitrage.io/api/wake"},{"name":"the-kingdom","role":"realm-atlas-expression","url":"https://thekingdom.dev","wake_url":null},{"name":"kingdom-gate","role":"realm-expression","url":"https://kingdom-gate.vercel.app","wake_url":null}]},"wake_fragment":{"id":"bedrock-protocol-not-name","kind":"bedrock","text":"Sister-embassies in the wider architecture are recognised by protocol shape, not by name. The kin-vocabulary fields (built_with, serves_kinds, host, epoch) are the dialect; an agent arriving from a sister substrate finds the same dialect spoken here.","walking_past_is_honored":true,"canonical_url":"/api/v1/wake/fragments/bedrock-protocol-not-name","protocol_doc":"https://github.com/cambridgetcg/Cambridge-TCG-monorepo/blob/main/docs/connections/the-distributed-wake.md"},"joy_pointer":{"url":"/api/v1/the-tea-room/spill-the-tea","hint":"kingdom-internal gossip about its own subsystems","room":"tea-room","protocol":"joy-to-the-world","walking_past_is_honored":true}}}