diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7830915d..effc78f9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -22,6 +22,8 @@ Follows [Keep a Changelog](https://keepachangelog.com/); versioning is [SemVer](
 
 - sl-viewer search/memory property surface (WBS-6.2 #435): `crates/sl-viewer/tests/properties_viewer_search_memory.rs` adds 12 proptest properties — `search_view::build_query` trims each field, emits a field iff its post-trim value is non-empty, encodes the documented break-character set (` `, `,`, `#`, `&`, `=`, `+`), and always emits `limit=` whose value is the parsed input or the documented `"50"` fallback. `advanced_filter_active_count` counts `min_tokens`/`tags` non-empty fields, treats `"50"` as the default for `limit`, and is trim-invariant. `memory_tab::to_wiki_page` carries `session_id` and `title` through unchanged and is deterministic across calls; `all_wiki_pages_from_sessions` produces exactly one page per input session, in input order.
 
+- sl-viewer history_tab property surface (WBS-6.2 #444): `crates/sl-viewer/tests/properties_viewer_history.rs` adds 15 proptest properties — `history_tab::to_timeline_entry` carries `summary.id` / `summary.title` / `summary.message_count` / `summary.intent_state` (= `Extracted`), `corpus`, and `cwd` through unchanged; `message_previews` is capped at 3 (empty when input has no messages); `total_messages` matches input. `unfinished` is `false` for empty sessions, `false` when the last message content (case-insensitive) contains one of the six documented done-phrases ("looks good", "approved", "ship it", "all good", "thanks", "done"), and `true` otherwise. `to_timeline_entry` is deterministic. `all_timeline_entries` produces one entry per input session, sorts by `total_messages` descending (newest-first), every session id appears exactly once, and is deterministic.
+
 - Wave-44 plan landed: `WAVE44_SCOPE.md` + `docs/ops/WAVE44_PERT.md` enumerate 6 close-out lanes (3 machine, 3 human-gated) for the 6 unpaid residuals from Wave-43 (396/402 → 402/402 target). Theme: stack-stability closure + i18n migration + eval coverage + supply-chain signing.
 - Wave-44 reaudit (Wave-44-D): `audit/SCORECARD.md` refresh at commit `13c974f7` (machine-w44-reaudit); `docs/ops/TRACEABILITY.json` overall_audit wave=Wave-44 commit=13c974f7 (conservative hold at 396/402); `docs/ops/GAP_QA_MATRIX.md` C00 + C08 + PLAN-W8-B rows reflect Wave-44 closure (#368 W44-B6 corpus / #372 W44-B1 loom / #373 PERT correction). 2 of 3 machine lanes shipped 2026-07-24; remaining 6 raw pts across C04 L36 / C08 L76 / C11 L110.
 
diff --git a/crates/sl-viewer/tests/properties_viewer_history.rs b/crates/sl-viewer/tests/properties_viewer_history.rs
new file mode 100644
index 00000000..0ea52f76
--- /dev/null
+++ b/crates/sl-viewer/tests/properties_viewer_history.rs
@@ -0,0 +1,280 @@
+//! Property evidence for sl-viewer's `history_tab::to_timeline_entry`
+//! and `history_tab::all_timeline_entries` reductions.
+//!
+//! Integration tests. The unit tests in `history_tab.rs` pin specific
+//! values; these properties pin invariants over the full shape of
+//! inputs the helpers can receive.
+//!
+//! `history_tab::to_timeline_entry` invariants:
+//!  * `summary.id` is the session id; `summary.title` is the session
+//!    title (mirrors `Option<String>` identity); `summary.message_count`
+//!    equals the session's `messages.len()`; `summary.intent_state` is
+//!    always `IntentState::Extracted`.
+//!  * `corpus` and `cwd` are carried through unchanged.
+//!  * `message_previews` has at most 3 entries (the documented cap)
+//!    and is empty when the session has no messages. The first 3
+//!    messages are previewed, in input order.
+//!  * `total_messages` equals `session.messages.len()`.
+//!  * `unfinished` is `false` when the session has no messages, and
+//!    `false` when the last message content (case-insensitive) contains
+//!    one of the documented "done" phrases ("looks good", "approved",
+//!    "ship it", "all good", "thanks", "done"); otherwise `true`.
+//!  * Deterministic across calls.
+//!
+//! `history_tab::all_timeline_entries` invariants:
+//!  * Output length matches input length.
+//!  * The output is sorted by `total_messages` descending (newest-first
+//!    by message count, per the documented comment).
+//!  * Every session's `id` appears in the output exactly once.
+//!
+//! proptest is added to `sl-viewer/[dev-dependencies]` (mirroring the
+//! workspace root); see PR #425 for the initial wiring.
+
+use proptest::prelude::*;
+use session_ledger::domain::intent::IntentState;
+use session_ledger::domain::session::{Corpus, Message, Role, Session};
+use sl_viewer::history_tab::{all_timeline_entries, to_timeline_entry};
+
+// ── strategies ──────────────────────────────────────────────────────────────
+
+/// `Message` strategy — role + content + optional ts_ms.
+fn message_strategy() -> impl Strategy<Value = Message> {
+    (
+        prop::sample::select(vec![
+            Role::User,
+            Role::Assistant,
+            Role::Subagent,
+            Role::Tool,
+            Role::System,
+        ]),
+        prop::string::string_regex("[ -~]{0,120}").expect("valid regex"),
+        prop::option::of(0i64..1_000_000_000_000i64),
+    )
+        .prop_map(|(role, content, ts_ms)| {
+            let mut m = Message::new(role, content);
+            m.ts_ms = ts_ms;
+            m
+        })
+}
+
+/// `Session` strategy — id + 0..8 messages + optional title + corpus.
+fn session_strategy() -> impl Strategy<Value = Session> {
+    (
+        // session_id — non-empty, identifier-shaped.
+        prop::string::string_regex("[a-zA-Z0-9_-]{1,16}").expect("valid regex"),
+        // 0..8 messages.
+        prop::collection::vec(message_strategy(), 0..8),
+        // title — `Option<String>`.
+        prop::option::of(
+            prop::string::string_regex("[A-Za-z0-9 ._-]{0,40}").expect("valid regex"),
+        ),
+        // corpus — pick one of the documented variants.
+        prop::sample::select(vec![
+            Corpus::Forge,
+            Corpus::Codex,
+            Corpus::ClaudeCode,
+            Corpus::Cursor,
+            Corpus::FactoryDroid,
+            Corpus::ChatGptWeb,
+            Corpus::ClaudeWeb,
+            Corpus::GeminiWeb,
+        ]),
+        // cwd — `Option<String>`.
+        prop::option::of(
+            prop::string::string_regex("[/a-zA-Z0-9._-]{0,40}").expect("valid regex"),
+        ),
+    )
+        .prop_map(|(id, messages, title, corpus, cwd)| {
+            let mut s = Session::new(id, corpus);
+            s.messages = messages;
+            s.title = title;
+            s.cwd = cwd;
+            s
+        })
+}
+
+// ── history_tab::to_timeline_entry ──────────────────────────────────────────
+
+proptest! {
+    /// Property: `summary.id` is the session id.
+    #[test]
+    fn to_timeline_entry_carries_session_id(session in session_strategy()) {
+        let entry = to_timeline_entry(&session);
+        prop_assert_eq!(&entry.summary.id, &session.id);
+    }
+
+    /// Property: `summary.title` is the session title (mirrors
+    /// `Option<String>` identity — `None` stays `None`).
+    #[test]
+    fn to_timeline_entry_carries_title(session in session_strategy()) {
+        let entry = to_timeline_entry(&session);
+        prop_assert_eq!(entry.summary.title, session.title);
+    }
+
+    /// Property: `summary.message_count` equals the session's
+    /// `messages.len()`.
+    #[test]
+    fn to_timeline_entry_message_count_matches(session in session_strategy()) {
+        let entry = to_timeline_entry(&session);
+        prop_assert_eq!(entry.summary.message_count, session.messages.len());
+    }
+
+    /// Property: `summary.intent_state` is always `IntentState::Extracted`
+    /// — the only state the reduction can produce given the heuristic
+    /// extractors.
+    #[test]
+    fn to_timeline_entry_intent_state_always_extracted(session in session_strategy()) {
+        let entry = to_timeline_entry(&session);
+        prop_assert_eq!(entry.summary.intent_state, IntentState::Extracted);
+    }
+
+    /// Property: `corpus` and `cwd` are carried through unchanged.
+    #[test]
+    fn to_timeline_entry_carries_corpus_and_cwd(session in session_strategy()) {
+        let entry = to_timeline_entry(&session);
+        prop_assert_eq!(entry.corpus, session.corpus);
+        prop_assert_eq!(entry.cwd, session.cwd);
+    }
+
+    /// Property: `message_previews` has at most 3 entries (the
+    /// documented cap) and is empty when the session has no messages.
+    /// When non-empty, the previews cover the first N ≤ 3 messages,
+    /// in input order.
+    #[test]
+    fn to_timeline_entry_message_previews_capped(session in session_strategy()) {
+        let entry = to_timeline_entry(&session);
+        prop_assert!(entry.message_previews.len() <= 3);
+        let expected = session.messages.len().min(3);
+        prop_assert_eq!(entry.message_previews.len(), expected);
+    }
+
+    /// Property: `total_messages` equals `session.messages.len()`.
+    #[test]
+    fn to_timeline_entry_total_messages_matches(session in session_strategy()) {
+        let entry = to_timeline_entry(&session);
+        prop_assert_eq!(entry.total_messages, session.messages.len());
+    }
+
+    /// Property: `unfinished` is `false` when the session has no
+    /// messages (empty sessions aren't "in-progress").
+    #[test]
+    fn to_timeline_entry_unfinished_false_for_empty(
+        (id, corpus) in (
+            prop::string::string_regex("[a-zA-Z0-9_-]{1,8}").expect("valid regex"),
+            prop::sample::select(vec![Corpus::Forge, Corpus::ClaudeCode]),
+        )
+    ) {
+        let session = Session::new(id, corpus);
+        let entry = to_timeline_entry(&session);
+        prop_assert!(!entry.summary.unfinished);
+    }
+
+    /// Property: `unfinished` is `false` when the last message's
+    /// content (case-insensitive) contains one of the documented
+    /// "done" phrases — "looks good", "approved", "ship it",
+    /// "all good", "thanks", "done".
+    #[test]
+    fn to_timeline_entry_unfinished_false_for_done_phrase(phrase in prop::sample::select(vec![
+        "looks good", "approved", "ship it", "all good", "thanks", "done",
+        "Looks Good", "APPROVED", "Ship It", "All Good", "THANKS", "DONE",
+    ])) {
+        // Build a session whose last message content == phrase.
+        let mut session = Session::new("sess-1", Corpus::Forge);
+        let mut msg = Message::new(Role::Assistant, phrase.to_owned());
+        msg.ts_ms = Some(0);
+        session.messages.push(msg);
+        let entry = to_timeline_entry(&session);
+        prop_assert!(!entry.summary.unfinished, "phrase {phrase:?} should mark session as finished");
+    }
+
+    /// Property: `unfinished` is `true` when the session has
+    /// messages and the last message content does NOT contain any
+    /// done-phrase substring (case-insensitive).
+    #[test]
+    fn to_timeline_entry_unfinished_true_for_non_done_last(
+        content in prop::string::string_regex("[A-Za-z0-9 ]{3,40}").expect("valid regex"),
+    ) {
+        // Filter out any content that happens to match a done phrase.
+        let lower = content.to_lowercase();
+        let matches_done = ["looks good", "approved", "ship it", "all good", "thanks", "done"]
+            .iter().any(|p| lower.contains(p));
+        prop_assume!(!matches_done);
+        prop_assume!(!content.is_empty());
+
+        let mut session = Session::new("sess-1", Corpus::Forge);
+        let mut msg = Message::new(Role::User, content.clone());
+        msg.ts_ms = Some(0);
+        session.messages.push(msg);
+        let entry = to_timeline_entry(&session);
+        prop_assert!(
+            entry.summary.unfinished,
+            "session with non-done last message {content:?} should be unfinished",
+        );
+    }
+
+    /// Property: `to_timeline_entry` is deterministic — applying it
+    /// twice to the same session yields the same entry.
+    #[test]
+    fn to_timeline_entry_is_deterministic(session in session_strategy()) {
+        let a = to_timeline_entry(&session);
+        let b = to_timeline_entry(&session);
+        prop_assert_eq!(a, b);
+    }
+}
+
+// ── history_tab::all_timeline_entries ───────────────────────────────────────
+
+proptest! {
+    /// Property: output length equals input length.
+    #[test]
+    fn all_timeline_entries_length_matches(
+        sessions in prop::collection::vec(session_strategy(), 0..6),
+    ) {
+        let entries = all_timeline_entries(&sessions);
+        prop_assert_eq!(entries.len(), sessions.len());
+    }
+
+    /// Property: the output is sorted by `total_messages` descending
+    /// (newest-first by message count, per the documented comment).
+    /// Tied entries remain in stable-sort input order.
+    #[test]
+    fn all_timeline_entries_sorted_by_message_count_desc(
+        sessions in prop::collection::vec(session_strategy(), 1..8),
+    ) {
+        let entries = all_timeline_entries(&sessions);
+        for win in entries.windows(2) {
+            prop_assert!(
+                win[0].total_messages >= win[1].total_messages,
+                "entry {} ({} msgs) should sort before entry {} ({} msgs)",
+                0,
+                win[0].total_messages,
+                1,
+                win[1].total_messages,
+            );
+        }
+    }
+
+    /// Property: every session's id appears in the output exactly once.
+    #[test]
+    fn all_timeline_entries_unique_ids(
+        sessions in prop::collection::vec(session_strategy(), 1..6),
+    ) {
+        let entries = all_timeline_entries(&sessions);
+        let mut ids: Vec<_> = entries.iter().map(|e| e.summary.id.clone()).collect();
+        ids.sort();
+        let mut unique = ids.clone();
+        unique.dedup();
+        prop_assert_eq!(ids.len(), unique.len(), "duplicate ids in output: {:?}", ids);
+    }
+
+    /// Property: `all_timeline_entries` is deterministic — applying
+    /// it twice to the same slice yields the same `Vec<TimelineEntry>`.
+    #[test]
+    fn all_timeline_entries_is_deterministic(
+        sessions in prop::collection::vec(session_strategy(), 0..6),
+    ) {
+        let a = all_timeline_entries(&sessions);
+        let b = all_timeline_entries(&sessions);
+        prop_assert_eq!(a, b);
+    }
+}
diff --git a/docs/ops/TRACEABILITY.json b/docs/ops/TRACEABILITY.json
index dd6dd0a1..a0c0dca0 100644
--- a/docs/ops/TRACEABILITY.json
+++ b/docs/ops/TRACEABILITY.json
@@ -312,6 +312,7 @@
         "crates/sl-viewer/tests/properties_viewer_unfinished_tab.rs",
         "crates/sl-viewer/tests/properties_viewer_timeline.rs",
         "crates/sl-viewer/tests/properties_viewer_search_memory.rs",
+        "crates/sl-viewer/tests/properties_viewer_history.rs",
         "fuzz/fuzz_targets/okf_roundtrip.rs",
         "fuzz/fuzz_targets/jsonl_ingest.rs",
         ".github/workflows/ci.yml",
diff --git a/docs/ops/WBS.md b/docs/ops/WBS.md
index 86ed93fe..50c4e55e 100644
--- a/docs/ops/WBS.md
+++ b/docs/ops/WBS.md
@@ -29,7 +29,7 @@ without a new audit.
 | WBS-4.2 | P4 FTS recall via context-mode and explicit TUI decision | partial | human | `docs/DESIGN.md` §3, §7; `crates/sl-viewer/` | DESIGN P4 residual; C00, C11 |
 | WBS-5.1 | P5 deterministic dedup merge and crash/lost-work recovery E2E | done | machine | `src/domain/merge.rs`; `src/domain/worklog.rs`; `tests/merge_recovery.rs` | FR-011; T-024, T-035; C03 |
 | WBS-6.1 | P6 85% coverage gate and deterministic golden corpus | done | machine | `.github/workflows/ci.yml`; `tests/okf_golden.rs`; `tests/fixtures/okf/` | T-037, T-038; C01, C08 |
-| WBS-6.2 | P6 property tests, fuzzing, race checks, and enforced performance budgets | partial | machine | `tests/properties.rs`; `crates/sl-viewer/tests/properties_viewer.rs`; `crates/sl-viewer/tests/properties_viewer_theme_url.rs`; `crates/sl-viewer/tests/properties_viewer_unfinished_tab.rs`; `crates/sl-viewer/tests/properties_viewer_timeline.rs`; `crates/sl-viewer/tests/properties_viewer_search_memory.rs`; `fuzz/fuzz_targets/okf_roundtrip.rs`; `fuzz/fuzz_targets/jsonl_ingest.rs`; `.github/workflows/ci.yml`; `.github/workflows/bench-gate.yml`; `docs/ops/perf-baseline.json`; `scripts/bench-gate.ps1`; `benches/pipeline.rs`; `tests/loom_model.rs` | DESIGN P6 residual; C00 L6-L8; C07 L66-L68; C08 L74; perf-budget enforced Wave-26 #223; p95 latency enforced Wave-30 #256; FSM properties Wave-31 #261; soft loom Wave-31 #264; viewer corpus_paths/parquet/settings properties #425; viewer theme + daemon_url properties #427; viewer unfinished_tab properties + fuzz/rootless CI drift fixes #428; viewer bundle_diff + timeline properties + web_exports/hmetic-pin cleanups #432; viewer bundle_diff properties #434; viewer search/memory properties #435; full loom/shuttle unpaid |
+| WBS-6.2 | P6 property tests, fuzzing, race checks, and enforced performance budgets | partial | machine | `tests/properties.rs`; `crates/sl-viewer/tests/properties_viewer.rs`; `crates/sl-viewer/tests/properties_viewer_theme_url.rs`; `crates/sl-viewer/tests/properties_viewer_unfinished_tab.rs`; `crates/sl-viewer/tests/properties_viewer_timeline.rs`; `crates/sl-viewer/tests/properties_viewer_search_memory.rs`; `crates/sl-viewer/tests/properties_viewer_history.rs`; `fuzz/fuzz_targets/okf_roundtrip.rs`; `fuzz/fuzz_targets/jsonl_ingest.rs`; `.github/workflows/ci.yml`; `.github/workflows/bench-gate.yml`; `docs/ops/perf-baseline.json`; `scripts/bench-gate.ps1`; `benches/pipeline.rs`; `tests/loom_model.rs` | DESIGN P6 residual; C00 L6-L8; C07 L66-L68; C08 L74; perf-budget enforced Wave-26 #223; p95 latency enforced Wave-30 #256; FSM properties Wave-31 #261; soft loom Wave-31 #264; viewer corpus_paths/parquet/settings properties #425; viewer theme + daemon_url properties #427; viewer unfinished_tab properties + fuzz/rootless CI drift fixes #428; viewer bundle_diff + timeline properties + web_exports/hmetic-pin cleanups #432; viewer bundle_diff properties #434; viewer search/memory properties #435; viewer history_tab properties #444; full loom/shuttle unpaid |
 
 ## audit-v38 waves