adeelahmad · Oct 4, 2026 · Oct 4, 2026
diff --git a/DEVLOG.md b/DEVLOG.md
@@ -199,7 +199,7 @@ Todo:
 - [x] Editor: BlockSuite (AFFiNE's block editor on Yjs documents, what OctoBase stores) behind one component; plain
       text kept for search and the assistant
 - [x] AI title and summary refinement (ai.refine_notes, on by default, can be switched off)
-- [ ] Costs of refinement to the activity ledger (once "Activity history and budgets&qu
8000
ot; lands)
+- [x] Costs of refinement and filing to the activity ledger (`note_page:id` and its namespace; shown on the page)
 - [x] Assistant tools: find, read, write and update notes (at once, no approval: notes are its notebook)
 - [ ] MCP tools to read notes; page history so the assistant's changes can be undone
 - [x] Self-organising, first step: notes nobody filed are filed in PARA by a decision model (or the LLM), with a

diff --git a/docs/activity.md b/docs/activity.md
@@ -14,6 +14,7 @@ Each row names every resource it counts for, as `table:id`:
 | A job, its recording, namespace and pipeline | `job:40`, `recording:7`, `space:1`, `pipeline:2` |
 | A workflow | `workflow:4` |
 | A chat | `chat:9` |
+| A note (its refinement and filing, and the requests that changed it) | `note_page:5` |
 | The person who asked | `account:1` |
 
 A model call inside a workflow step of a job that a routine queued counts for the workflow, the job, the recording,

diff --git a/docs/notes.md b/docs/notes.md
@@ -48,8 +48,9 @@ With **Settings → Assistant → Keep note titles and summaries up to date** (`
 whose title or text changed is sent to the model once nobody has touched it for two minutes. The model rewrites the
 one-line summary to fit the whole note, and the title only when it is empty, "Untitled" or no longer fits. A note being
 typed is never sent on each keystroke, empty notes are never sent, and nothing is sent without a model configured. The
-API and `lens worker` processes run this pass with the routines. Model calls are measured by telemetry; their costs go
-to the activity ledger once it exists.
+API and `lens worker` processes run this pass with the routines. Each model call, and each filing decision, counts in
+the [activity ledger](activity.md) for the note (`note_page:5`) and its namespace; a note's page shows its costs and
+activity at the bottom.
 
 ## Filing (PARA)
 

diff --git a/fastapi_backend/app/api/v1/routes/activity.py b/fastapi_backend/app/api/v1/routes/activity.py
@@ -1,6 +1,6 @@
 """The activity ledger (docs/activity.md): a resource's history (its calls in and out, runs and changes) and what it
-cost. Admins see every resource's; others see their own account's, their chats', and the recordings and namespaces they
-can read."""
+cost. Admins see every resource's; others see their own account's, their chats', and the recordings, notes and namespaces
+they can read."""
 
 from __future__ import annotations
 
@@ -40,6 +40,12 @@ def _may_see(db: Db, user: CurrentUser, acl: Acl, resource: str) -> None:
                 raise HTTPException(404, "not found")
             acl.need(e["space"])
             return
+        if table == "note_page":
+            page = db.one("SELECT space FROM $r", r=activity.R("note_page", int(key)))
+            if not page:
+                raise HTTPException(404, "not found")
+            acl.need(page["space"])
+            return
         if table == "chat" and db.one("SELECT id FROM $r WHERE account = $a", r=activity.R("chat", int(key)), a=user.id):
             return
     raise HTTPException(403, "only admins see this resource's activity")

diff --git a/fastapi_backend/app/domain/activity.py b/fastapi_backend/app/domain/activity.py
@@ -54,7 +54,7 @@
     "watches": "watch_path",
     "sensors": "sensor",
     "templates": "template",
-    "notes": "note",
+    "notes": "note",  # a recording's notes; /api/v1/notes/{id} are note pages (_table)
     "comments": "comment",
     "entities": "entity",
     "speakers": "speaker",
@@ -120,13 +120,20 @@ def current():
     return list(dict.fromkeys(r for r in out if REF.match(r)))
 
 
+def _table(parts, i):
+    """The table a key after path segment i names: /api/v1/notes/{id} are note pages, a recording's notes/{id} its notes."""
+    if parts[i] == "notes" and i and parts[i - 1] == "v1":
+        return "note_page"
+    return TABLES.get(parts[i])
+
+
 def request_refs(asgi):
     """An API request's resources: each number (or path parameter) after a known path segment, and who called."""
     out = []
     params = {str(v) for v in (asgi.get("path_params") or {}).values()}
     parts = [p for p in (asgi.get("path") or "").split("/") if p]
-    for a, b in zip(parts, parts[1:]):
-        table = TABLES.get(a)
+    for i, b in enumerate(parts[1:]):
+        table = _table(parts, i)
         if table and (b.isdigit() or b in params) and b not in TABLES:
             out.append(ref(table, b))
     p = (asgi.get("state") or {}).get("principal")
@@ -322,7 +329,8 @@ def _log(self, scope_, app, db, status, error, t0, head=b""):
 
 def created(path, head):
     """What a POST to a collection made, from its reply ({"id": n}): `routine:7` for POST /api/v1/routines."""
-    table = TABLES.get(path.rstrip("/").rsplit("/", 1)[-1])
+    parts = [p for p in path.split("/") if p]
+    table = _table(parts, len(parts) - 1) if parts else None
     if not table or not head:
         return None
     try:

diff --git a/fastapi_backend/app/domain/notebook.py b/fastapi_backend/app/domain/notebook.py
@@ -23,7 +23,7 @@
 import datetime as dt
 import re
 
-from . import store
+from . import activity, store
 
 R = store.R
 PLACES = ("project", "area", "resource", "archive")
@@ -450,19 +450,25 @@ def follow(db, thing, dst):
 )
 
 
+def _refs(p):
+    """What the model calls made for a page count for in the activity ledger: the page and its namespace."""
+    return (f"note_page:{p['id']}", f"space:{p['space']}")
+
+
 def refine(db, cfg, pid):
     """Ask the model for the page's title and summary; saved unless someone changed the page meanwhile. Returns what
     changed: {"title"?, "summary"?}."""
     from . import llm
 
-    p = db.one("SELECT record::id(id) AS id, title, summary, text, updated_at FROM $r", r=R("note_page", int(pid)))
+    p = db.one("SELECT record::id(id) AS id, space, title, summary, text, updated_at FROM $r", r=R("note_page", int(pid)))
     if not p:
         raise KeyError(pid)
     if not (p.get("text") or "").strip():
         db.q("UPDATE $r SET refine_pending = false, refine_claim = NONE", r=R("note_page", p["id"]))
         return {}
     user = f"Title: {p['title']}\nSummary: {p.get('summary') or '(none)'}\n\nNote:\n{p['text'][:REFINE_CHARS]}"
-    out = llm.json_out(cfg, REFINE_SYSTEM, user, REFINE_SCHEMA)
+    with activity.scope(db, *_refs(p), cfg=cfg):
+        out = llm.json_out(cfg, REFINE_SYSTEM, user, REFINE_SCHEMA)
     title = " ".join(str(out.get("title") or "").split())[:TITLE_MAX] or p["title"]
     summary = " ".join(str(out.get("summary") or "").split())[:SUMMARY_MAX] or p.get("summary")
     now = db.one("SELECT updated_at FROM $r", r=R("note_page", p["id"]))
@@ -528,15 +534,16 @@ def file_due(db, cfg, log=None):
     if not cfg["ai"].get("organise_notes", True) or not decide.engine(cfg):
         return 0
     rows = db.rows(
-        "SELECT record::id(id) AS id, title, summary, text, updated_at FROM note_page "
+        "SELECT record::id(id) AS id, space, title, summary, text, updated_at FROM note_page "
         "WHERE about = NONE AND filed != true AND refine_pending != true LIMIT $n",
         n=FILE_BATCH,
     )
     done = 0
     for p in rows:
         state = {"title": p["title"], "summary": p.get("summary"), "text": (p.get("text") or "")[:4000]}
         try:
-            d = decide.choose(cfg, "Where does this note belong in PARA (projects, areas, resources, archives)?", PARA, state)
+            with activity.scope(db, *_refs(p), cfg=cfg):
+                d = decide.choose(cfg, "Where does this note belong in PARA (projects, areas, resources, archives)?", PARA, state)
         except decide.Undecided as e:
             if log:
                 log(f"notes: couldn't file page {p['id']}: {e}")

diff --git a/fastapi_backend/tests/api/test_notebook.py b/fastapi_backend/tests/api/test_notebook.py
@@ -191,6 +191,11 @@ def test_refining_titles_and_summaries(client, env, db, cfg, llm):
     assert notebook.refine_due(db, cfg) == 1
     got = client.get(f"/api/v1/notes/{p['id']}", headers=he).json()
     assert (got["title"], got["summary"], got["summary_by"]) == ("Capsid plan", "About Capsid samples ship on Friday.", "assistant")
+    # what it cost counts for the page and its namespace, and the page's readers see it with the requests that changed it
+    led = client.get("/api/v1/activity", headers=he, params={"resource": f"note_page:{p['id']}"}).json()
+    kinds = {(e["kind"], e["action"]) for e in led}
+    assert ("out", "model.chat") in kinds and any(k == "in" for k, _ in kinds), kinds
+    assert any(e["kind"] == "out" and f"space:{store.ns_id(db, got['namespace'])}" in e["resources"] for e in led)
     # done until the note changes; a person's title change makes it due again, and their own title stays
     assert notebook.refine_due(db, cfg) == 0
     client.patch(f"/api/v1/notes/{p['id']}", headers=he, json={"title": "Shipping"})

diff --git a/nextjs-frontend/components/notes/note-page.tsx b/nextjs-frontend/components/notes/note-page.tsx
@@ -9,6 +9,7 @@ import { useCallback, useEffect, useRef, useState } from "react";
 
 import { Notes } from "@/app/openapi-client";
 import type { NotePage as Page, NotePageDraft as PageDraft } from "@/app/openapi-client/types.gen";
+import { ActivityPanel } from "@/components/costs/costs";
 import type { EditorChange, LinkTarget } from "@/components/notes/block-editor";
 import { PLACES, hrefFor } from "@/components/notes/links";
 import { Button } from "@/components/ui/button";
@@ -327,6 +328,7 @@ export function NotePage({ id, about }: { id?: number; about?: string }) {
         >
       />
       <Backlinks items={page.backlinks ?? []} />
+      {saved && <ActivityPanel resource={`note_page:${saved.id}`} title="Costs and activity" />}
     </article>
   );
 }