diff --git a/crates/aura-cli/tests/cli_run.rs b/crates/aura-cli/tests/cli_run.rs
index 33dac96..a3fec65 100644
--- a/crates/aura-cli/tests/cli_run.rs
+++ b/crates/aura-cli/tests/cli_run.rs
@@ -6707,3 +6707,86 @@ fn show_is_scoped_to_its_own_document_store() {
         "campaign show stderr: {campaign_stderr}"
     );
 }
+
+/// Property (#302): `show` mirrors the prefix resolution `reproduce` gained
+/// with #298 — a unique prefix of a registered content id, in the 8-hex form
+/// every surface prints (family ids, run records), resolves to the registered
+/// document, and `show` prints EXACTLY the bytes the full-id invocation
+/// prints (the #164 byte-discipline: the stored canonical bytes, no framing).
+/// One document per store makes any prefix of its id unique by construction.
+/// Deliberately NOT pinned here: the ambiguous-prefix refusal (listing the
+/// candidate ids) — content ids are hash-derived, not choosable, so two
+/// documents sharing a printed prefix cannot be constructed honestly at this
+/// layer; that arm belongs beside the resolution seam, where candidate id
+/// lists are plain strings.
+#[test]
+fn show_resolves_a_unique_prefix_to_the_full_id_bytes() {
+    let (cwd, _g) = fresh_project();
+
+    fn aura(cwd: &Path, args: &[&str]) -> std::process::Output {
+        Command::new(BIN).args(args).current_dir(cwd).output().expect("spawn aura")
+    }
+
+    const PREFIX_PROBE_PROCESS: &str = r#"{"format_version":1,"kind":"process","name":"prefix-probe","pipeline":[{"block":"std::sweep","metric":"sqn_normalized","select":"argmax"}]}"#;
+    const PREFIX_PROBE_CAMPAIGN: &str = r#"{
+  "format_version": 1,
+  "kind": "campaign",
+  "name": "prefix-probe",
+  "data": { "instruments": ["GER40"], "windows": [ { "from_ms": 1, "to_ms": 2 } ] },
+  "strategies": [ { "ref": { "content_id": "9f3a" },
+                    "axes": { "fast": { "kind": "I64", "values": [8] } } } ],
+  "process": { "ref": { "content_id": "4e2d" } },
+  "seed": 1,
+  "presentation": { "persist_taps": [], "emit": ["family_table"] }
+}"#;
+
+    for (verb, file, doc) in [
+        ("process", "probe.process.json", PREFIX_PROBE_PROCESS),
+        ("campaign", "probe.campaign.json", PREFIX_PROBE_CAMPAIGN),
+    ] {
+        std::fs::write(cwd.join(file), doc).expect("write document");
+        let register = aura(&cwd, &[verb, "register", file]);
+        assert_eq!(
+            register.status.code(),
+            Some(0),
+            "{verb} register must succeed: {}",
+            String::from_utf8_lossy(&register.stderr)
+        );
+        let register_out = String::from_utf8_lossy(&register.stdout).into_owned();
+        let marker = format!("registered {verb} ");
+        let id = register_out
+            .lines()
+            .find(|l| l.starts_with(&marker))
+            .expect("register line")
+            .trim_start_matches(marker.as_str())
+            .split(' ')
+            .next()
+            .expect("content id")
+            .to_string();
+        assert!(id.len() > 8, "content id longer than the printed 8-hex prefix form: {id}");
+
+        let full = aura(&cwd, &[verb, "show", &id]);
+        assert_eq!(
+            full.status.code(),
+            Some(0),
+            "{verb} show <full id> must succeed: {}",
+            String::from_utf8_lossy(&full.stderr)
+        );
+        assert!(!full.stdout.is_empty(), "{verb} show <full id> prints the document bytes");
+
+        // The headline: the 8-hex prefix — unique in this one-document store —
+        // resolves, and the output is byte-identical to the full-id output.
+        let prefix = &id[..8];
+        let short = aura(&cwd, &[verb, "show", prefix]);
+        assert_eq!(
+            short.status.code(),
+            Some(0),
+            "{verb} show {prefix} (unique prefix of {id}) must resolve: {}",
+            String::from_utf8_lossy(&short.stderr)
+        );
+        assert_eq!(
+            short.stdout, full.stdout,
+            "{verb} show via unique prefix must print the identical document bytes"
+        );
+    }
+}