fix(tui): coalesce thinking deltas on \n (v0.7.1)

Operator: "thinking tokens seem to be split by token — each on a
newline, is that correct? We don't want that."

Root cause: v0.6.5 wrote each Thinking SSE delta as its own
`thinking_log.write(event.content)` call. Worldtree emits Thinking
events at token granularity (per-token or per-few-tokens), so EACH
token became its own RichLog line — visually choppy, one short
fragment per visual row. Wrong UX.

## Fix: coalesce-on-newline

Thinking deltas accumulate in `TuiPresenterState.thinking_chunk_buffer`
(new str field). On each Thinking event:

  1. Append delta content to buffer.
  2. Flush every COMPLETE line (chars before each `\n`) as one
     thinking_log.write(line) call.
  3. Leave the post-final-`\n` tail in the buffer for the next delta.

On any non-thinking event (run close):
  1. Flush remaining buffer tail (if any) as one final line.
  2. Write Rule(end).

Empty lines (blank paragraph separators in the model's `\n\n` flow)
are skipped — they'd render as no-content RichLog entries which
just add vertical noise. Natural paragraph breaks become single
visible lines; multi-paragraph thinking renders top-to-bottom.

## Verified live (tier-3 smoke against personal Worldtree)

Defined a `thinky-smoke` agent via `python -m ratatoskr.tier3 define`,
asked "What is 12 times 13?". Thinking pane rendered with natural
paragraph chunks:

  ── turn N · thinking #1 start ──
  Thinking Process:
  1.  **Analyze the Request:** The user wants to know the result of $12 \times 13$.
  2.  **Calculate:**
      *   Method 1: Standard multiplication.
          $$12 \times 10 = 120$$
          $$12 \times 3 = 36$$
          $$120 + 36 = 156$$
      *   Method 2: $(10 + 2)(10 + 3) = 100 + 30 + 20 + 6 = 156$.
  ── turn N · thinking #1 end ──

Each line = one natural paragraph or list item. No per-token fragments.

## Edge cases noted

- Long-running thinking with NO `\n` at all stays buffered until run
  close → operator sees nothing until close. Possible follow-up: add
  a length-threshold flush (e.g., > 500 chars → flush at the last
  space). For now this is acceptable; thinking content typically has
  `\n` breaks every few sentences.
- Empty deltas (`""`) are ignored implicitly — no buffer growth, no
  flush.
- `\n` at the very start of a delta flushes whatever was buffered
  before, then leaves the empty post-`\n` tail (empty string) in the
  buffer, which doesn't show up as an empty line because of the
  `if line:` guard.

## Contract amendment

docs/contracts/issues/13.contract.md INV-022 amended for v0.7.1
coalesce semantics. Drift-check clean.

## Tests

265/265 GREEN; ruff clean. Two updated tests:

- `test_thinking_streams_into_thinking_log` → renamed
  `test_thinking_coalesces_until_newline`: 3 token-shaped deltas
  with no `\n` → only Rule(start) writes, buffer holds accumulated.
- NEW `test_thinking_flushes_on_newline`: delta carrying `\n` →
  Rule(start) + accumulated line + clear buffer.
- `test_thinking_closes_to_thinking_log`: 2 deltas "a", "b" +
  close → Rule(start) + tail-flush "ab" + Rule(end) = 3 writes
  (was 4 with per-delta).

Patch bump (v0.7.0 → v0.7.1) — internal presenter routing change;
no public-API or layout change.

docs/contracts/issues/13.contract.md

@@ -161,7 +161,7 @@ New `Static(id="pane-name")` widget alongside the existing `identity` + `hint` w
 - **INV-019** *(amended v0.6.0)*: Three TabPanes in the right column: `Tools` (id `tools-tab`, contains `#tools-log`) + `Debug` (id `debug-tab`, contains `#debug-log`) + `Thinking` (id `thinking-tab`, contains `#thinking-log`). Ctrl+1/Ctrl+2/Ctrl+3 activate respective tabs. `pane-name` Static reflects active tab name dynamically.
 - **INV-020** *(amended v0.6.0)*: Render-exception fallback (INV-009) preserves routing per event class: `ToolStart` / `ToolResult` → `tools_log`; `Thinking` → `thinking_log`; `WorkerPhase` / `TextBoundary` → `debug_log`; everything else → `log`.
 - **INV-021** *(new v0.6.0)*: `Text` events do NOT route to `log` per-delta. They accumulate into `TuiPresenterState.text_buffer` and update a single `current_text` Static (docked above the prompt). On terminal event (`Done`/`Error`/`Cancelled`), `current_text` is cleared and (raw mode) accumulated text or (non-raw) post-Done `Markdown(response)` is written to `log`. The pre-v0.6.0 per-token RichLog spam is retired.
-- **INV-022** *(amended v0.6.5)*: Thinking deltas stream DIRECTLY into `thinking_log` (one delta = one RichLog line). The first delta of a run writes `Rule(title=f"turn N · thinking #K start")`; subsequent deltas write their raw content as lines; the run closes on the next non-thinking event with `Rule(title=f"turn N · thinking #K end")`. Pre-v0.6.5 markdown re-render dropped — the streamed deltas ARE the content; the whole pane scrolls naturally as content arrives.
+- **INV-022** *(amended v0.7.1)*: Thinking deltas COALESCE on `\n` boundaries before writing to `thinking_log`. The first delta of a run writes `Rule(title=f"turn N · thinking #K start")`; subsequent deltas accumulate in `TuiPresenterState.thinking_chunk_buffer`; whenever the buffer contains `\n`, the leading line(s) flush as RichLog entries (one entry per natural paragraph). The run closes on the next non-thinking event: any tail in the buffer flushes as a final line, then `Rule(title=f"turn N · thinking #K end")`. Pre-v0.7.1 per-delta-per-line caused token-spam (Worldtree emits thinking at token granularity); coalescing produces one log line per natural paragraph, not per token.
 - **INV-023** *(new v0.6.0)*: Turn-ID header `Rule(title=f"turn N")` is written to all four log panes (`log`, `tools_log`, `debug_log`, `thinking_log`) by `_stream_turn_worker` on the first event of each turn — enables cross-pane visual correlation during multi-turn debugging.
 - **INV-024** *(amended v0.6.5)*: `thinking-current` Static REMOVED. v0.6.1 placed it inside the Thinking pane (docked bottom); operators reported the bottom-docked Static "scrolling a little section at the bottom" (its 200-char tail acting as a scroll-window) instead of letting the whole pane scroll. v0.6.5 deletes the Static entirely and streams Thinking deltas directly into `thinking_log` (the scrollable RichLog) — the whole pane scrolls naturally as content arrives. The Rule(start) at the first delta of a run is now the live "thinking is happening" indicator.
 

persistent-memory.md

@@ -32,9 +32,9 @@ separate dev team rather than an in-tree Worldtree tool.
 
 ## Current state / in-flight
 
-_As of 2026-05-25 (post-v0.7.0 Tier 3 agent lifecycle):_
+_As of 2026-05-25 (post-v0.7.1 thinking coalesce-by-newline):_
 
-**Status: v0.7.0 shipped.** Ten core features complete (`sse_client`
+**Status: v0.7.1 shipped.** Ten core features complete (`sse_client`
 #1, `sessions` #2, `cli` #3, `tui` #4, `--end-user-id` #5, TUI
 startup error visibility #6, presenter contract semantics amendment
 #12, startup agent picker #8, §5 layout reshape + Tools pane #13)
@@ -51,7 +51,8 @@ Static in the footer (static "Tools" v1; dynamic when more tabs
 land). CLI mode (--send) unaffected by design — INV-018.
 
 Last commits on `main`:
-- v0.7.0 feat(tier3): ratatoskr.tier3 module + CLI — Worldtree Tier 3 lifecycle
+- v0.7.1 fix(tui): coalesce thinking deltas on `\n` — no more per-token newlines
+- `c086ae2` feat(tier3): ratatoskr.tier3 module + CLI (v0.7.0)
 - `d356990` refactor(tui): thinking streams into thinking-log (v0.6.5)
 - `82437bd` style(tui): picker highlighted item → Aurora blue (v0.6.4)
 - `ac690c1` style(tui): restore Australis palette, only $background → pure black (v0.6.3)

pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "ratatoskr"
-version = "0.7.0"
+version = "0.7.1"
 description = "Worldtree Conversation API debug TUI — multi-pane observability dashboard"
 readme = "README.md"
 requires-python = ">=3.12"

src/ratatoskr/tui.py

@@ -191,6 +191,12 @@ class TuiPresenterState:
     text_buffer: list[str] = field(default_factory=list)
     # Thinking-run counter for turn-scoped start/end markers.
     thinking_run_index: int = 0
+    # v0.7.1: thinking-content accumulator. Worldtree emits Thinking deltas
+    # at token granularity; flushing each delta as its own RichLog line
+    # produces per-token-per-newline visual spam. Buffer here and flush
+    # only on `\n` boundaries (one written line per natural paragraph) or
+    # when the run closes (any leftover tail).
+    thinking_chunk_buffer: str = ""
 
     def render(
         self,
@@ -234,10 +240,11 @@ class TuiPresenterState:
             return RichText(s, style=_AU_DEMOTED)
 
         try:
-            # v0.6.5: Thinking deltas stream directly into thinking_log.
-            # First delta of a run writes the Rule(start) header; each
-            # subsequent delta writes its content as a line; the run closes
-            # on the next non-thinking event with a Rule(end).
+            # v0.7.1: Thinking deltas coalesce by newline before flushing.
+            # Worldtree emits Thinking events at token granularity; per-delta
+            # RichLog writes produce one visual line per token (per-token-per-
+            # newline spam). Buffer the deltas and flush only on `\n` (one
+            # written line per natural paragraph) or run close.
             if isinstance(event, Thinking):
                 from rich.rule import Rule
 
@@ -249,13 +256,24 @@ class TuiPresenterState:
                         style=_AU_DEMOTED,
                     ))
                     self.thinking_open = True
-                # Stream the delta content (chunk-of-tokens) as one line.
-                thinking_log.write(event.content)
+                self.thinking_chunk_buffer += event.content
+                # Flush every complete line in the buffer. Whatever's after
+                # the final `\n` stays buffered for the next delta or close.
+                while "\n" in self.thinking_chunk_buffer:
+                    line, _, rest = self.thinking_chunk_buffer.partition("\n")
+                    if line:  # skip empty lines (blank paragraph separators)
+                        thinking_log.write(line)
+                    self.thinking_chunk_buffer = rest
                 return
             # Non-thinking event: close any open thinking run with Rule(end).
             if self.thinking_open:
                 from rich.rule import Rule
 
+                # Flush the tail (content with no trailing `\n`) before the
+                # end rule so nothing gets lost on close.
+                if self.thinking_chunk_buffer:
+                    thinking_log.write(self.thinking_chunk_buffer)
+                    self.thinking_chunk_buffer = ""
                 turn_id = event.sse_id.turn_id if hasattr(event, "sse_id") else (
                     event.turn_id if hasattr(event, "turn_id") else "?"
                 )

tests/test_tui.py

@@ -115,10 +115,11 @@ SID = SseId(42, 5)
 class TestTuiPresenterState:
     """Tests for the new TuiPresenterState — per issue #12 contract."""
 
-    def test_thinking_streams_into_thinking_log(self) -> None:
-        """thinking_streams_into_thinking_log [happy,tracer, v0.6.5]:
-        3 Thinking deltas → thinking_log gets Rule(start) + 3 delta lines.
-        Transcript untouched; no thinking-current Static involved.
+    def test_thinking_coalesces_until_newline(self) -> None:
+        """thinking_coalesces_until_newline [happy,tracer, v0.7.1]:
+        Per-token deltas accumulate in the buffer; flush only on `\\n`.
+        Three short token-shaped deltas without `\\n` → thinking_log gets
+        ONLY Rule(start); content stays buffered.
         """
         from rich.rule import Rule
 
@@ -127,7 +128,7 @@ class TestTuiPresenterState:
         log = MagicMock()
         thinking_log = MagicMock()
         state = TuiPresenterState()
-        for chunk in ("a", "b", "c"):
+        for chunk in ("Let", " me", " think"):
             state.render(
                 Thinking(sse_id=SID, content=chunk),
                 log=log,
@@ -138,19 +139,41 @@ class TestTuiPresenterState:
                 raw=False,
             )
         writes = [c[0][0] for c in thinking_log.write.call_args_list]
-        # 1 Rule(start) + 3 content lines = 4 writes
-        assert len(writes) == 4
+        # Only Rule(start) — content stays buffered (no `\n` seen).
+        assert len(writes) == 1
         assert isinstance(writes[0], Rule)
-        assert writes[1] == "a"
-        assert writes[2] == "b"
-        assert writes[3] == "c"
-        # Transcript untouched during thinking streaming.
+        assert state.thinking_chunk_buffer == "Let me think"
         assert log.write.call_count == 0
 
+    def test_thinking_flushes_on_newline(self) -> None:
+        """thinking_flushes_on_newline [happy, v0.7.1]:
+        Delta carrying `\\n` flushes the accumulated buffer as ONE line.
+        """
+        from ratatoskr.tui import TuiPresenterState
+
+        thinking_log = MagicMock()
+        state = TuiPresenterState()
+        for chunk in ("Hello", " world", "\n"):
+            state.render(
+                Thinking(sse_id=SID, content=chunk),
+                log=MagicMock(),
+                tools_log=MagicMock(),
+                debug_log=MagicMock(),
+                current_text=MagicMock(),
+                thinking_log=thinking_log,
+                raw=False,
+            )
+        writes = [c[0][0] for c in thinking_log.write.call_args_list]
+        # Rule(start) + "Hello world" (one coalesced line) = 2 writes
+        assert len(writes) == 2
+        assert writes[1] == "Hello world"
+        assert state.thinking_chunk_buffer == ""
+
     def test_thinking_closes_to_thinking_log(self) -> None:
-        """thinking_closes_to_thinking_log [happy, v0.6.5]: 2x Thinking + WorkerPhase →
-        thinking_log gets Rule(start) + 2 delta lines + Rule(end); debug_log gets
-        the worker_phase line; transcript untouched.
+        """thinking_closes_to_thinking_log [happy, v0.7.1]: 2x Thinking + WorkerPhase →
+        v0.7.1 coalesces "a"+"b" into one buffered string; the close flushes
+        "ab" as a single line before Rule(end). Result: Rule(start) + "ab" +
+        Rule(end) = 3 writes. debug_log gets worker_phase; transcript untouched.
         """
         from rich.rule import Rule
 
@@ -180,12 +203,11 @@ class TestTuiPresenterState:
             raw=False,
         )
         thinking_writes = [c[0][0] for c in thinking_log.write.call_args_list]
-        # 1 Rule(start) + 2 delta lines + 1 Rule(end) = 4 writes
-        assert len(thinking_writes) == 4
+        # v0.7.1: 1 Rule(start) + 1 coalesced "ab" tail-flush + 1 Rule(end) = 3 writes
+        assert len(thinking_writes) == 3
         assert isinstance(thinking_writes[0], Rule)
-        assert thinking_writes[1] == "a"
-        assert thinking_writes[2] == "b"
-        assert isinstance(thinking_writes[3], Rule)
+        assert thinking_writes[1] == "ab"
+        assert isinstance(thinking_writes[2], Rule)
         # worker_phase still goes to debug_log; transcript untouched.
         assert "· worker_phase:" in _text_of(debug_log.write.call_args_list[-1][0][0])
         assert not log.write.called

uv.lock

@@ -968,7 +968,7 @@ wheels = [
 
 [[package]]
 name = "ratatoskr"
-version = "0.7.0"
+version = "0.7.1"
 source = { editable = "." }
 dependencies = [
     { name = "httpx" },