Trace a project to a message

Claude Code Cost goes down in three steps. The overview lists projects, a project lists its sessions, and a session lists its messages. Click a row in the Projects table on the overview to open that project’s sessions. Click a session to open its detail.

The sessions list and the session detail count different things. The list counts only messages inside the selected date range. The detail counts the whole session. Read All-time totals and the range before you compare the two.

Sessions list

The top of the view has a breadcrumb, Overview / <project>. Click Overview to go back.

Under the breadcrumb are three boxes:

A cost chart stacked by model. The title is Hourly Cost for Today, Last 24h, or a one-day custom range. For other ranges it is Daily Cost.
Cost by Model, the cost of each model in this project for the range.
Total Cost, the sum of the sessions in the table, with the number of sessions under it.

Sessions table

Column	What it shows
Session	The custom title of the session. If it has none, the first prompt. If it has no prompt, the session id.
Cost	Cost of the messages in the range.
Tokens	Input, output, cache write, and cache read tokens in the range.
Messages	Messages in the range. A tag such as `2× compact` shows how many compactions happened in the range.
Duration	Time from the first to the last message of the whole session.
Model	The model used for the most messages in the range.
Last Active	Time since the last message.

The table starts sorted by Last Active, newest first. Click a column header to sort by it. Click it again to flip the order. The Model column does not sort.

A session appears only if it has at least one message in the range. If no session does, the view shows No sessions found for this project. Pick a longer range to see older sessions. See Choose a date range and project scope.

Session detail

The breadcrumb is Overview / <project> / <session>. Click the project name to go back to its sessions. Under the breadcrumb, the first prompt of the session shows in italics.

The header has these stats:

Total Cost, marked all time
Input, Output, Cache Created, and Cache Read tokens
Messages, marked all time
Models, every model the session used
Compactions, with their estimated cost. This stat shows only when the session has compactions.

The costs of subagents and Workflow runs started from this session are in these totals. Each agent adds one row to the messages table.

All-time totals and the range

The detail header always covers the whole session. The sessions list covers only the range. So a session that started before the range shows a larger cost in the detail than in the list.

When only part of the session is in the range, a note under the header shows both parts:

Totals above are all-time · last 3 days $1.20 / 40 msg · today $0.30 / 12 msg

The first part is the range slice and the second part is today. A part shows only when it is a real subset of the session, with some messages but not all. The today part also does not show when it has the same messages as the range slice. If the whole session is in the range, the note does not show.

Compaction note

If the session has compactions, a second note shows:

How many were auto and how many were manual.
How many tokens the compactions dropped.
The summarizer cost, marked estimate, not in total. The transcript does not log the summary call, so Claude Code Cost estimates it. The total does not include it.
The cache re-warm cost and tokens, marked in total. This is the cache write on the turn after the compaction. The total already includes it.

See How costs are computed for the estimate.

Workflows

If the session started Workflow runs, a Workflows (N) table shows one row per run:

Column	What it shows
Workflow	Name of the run.
Agents	Number of agents in the run.
Span	Minutes from the first to the last message of the run.
Input	Input, cache write, and cache read tokens together.
Output	Output tokens.
Cost	Cost of the run.
Share	Percent of the session cost.

Charts

Cumulative Cost is a line of the running total, by message number.
Token Breakdown per Message stacks Input, Output, Cache Create, and Cache Read for each message.

Subagent messages look different so you can tell them from main-loop turns. In the bar chart their bars are faded. In the line chart their points are hollow, if the charts show 50 messages or fewer. Above 50 messages the line has no points. A dashed line labelled compact marks each compaction on both charts.

Range brush

A session with more than 25 messages gets a range brush between the charts and the messages table. The brush picks which messages the charts and the table show. It starts on the last 25 messages.

Click a preset to set the window size: 25, 50, 100, 200, or All. Only presets smaller than the session show.
Drag the window to move it. Drag an edge to resize it. The window is never smaller than 10 messages.
Click the track to center the window on that spot.
Scroll the mouse wheel over the track to pan.
With the track focused, press ← or → to pan one step (a tenth of the window), Shift+← or Shift+→ to pan a full window, and Home or End to go to the start or end.

The track has markers for cache bursts, compactions, and Workflow spans. The label above the track counts each kind. Click a marker to center the window on it.

A cache burst is a main-loop turn that wrote much more cache than usual for this session. Its cache write is at least 20,000 tokens and at least 4 times the session median cache write. The brush looks for bursts only when the session has 5 or more main-loop turns that wrote cache. The turn right after a compaction gets a compaction marker instead.

If the window is at the end of the session, it stays there when new messages arrive. If you moved it back, it stays where you put it.

Messages table

Column	What it shows
#	Message number in the session.
Time	Local time of the message.
Model	The model, with a tag for each tool the turn called. Subagent rows get a tag with the agent type, or `workflow` for a Workflow agent.
Input	Input tokens.
Output	Output tokens.
Cache Cr.	Cache write tokens.
Cache Rd.	Cache read tokens.
Cost	Cost of the message.
Cumulative	Running total up to this message.

The newest message is at the top. The title is Messages (N) when the table shows the whole session, or Messages (n of N) when the brush shows part of it. A compaction adds a row under its message, with the trigger, the token drop, the time it took, and the estimated cost marked est..

Deep links

The URL keeps your place, so you can bookmark a session or reload the page:

?view=insights opens Insights.
?project=<encoded dir> opens that project’s sessions.
?session=<id> opens that session’s detail.

If the session is not found in the current Claude config dir, from a link or from the last place you were, Claude Code Cost shows the toast Not in this config dir — showing overview and opens the overview.

Go back

Press Backspace or Esc, or click a part of the breadcrumb.

From a session detail, back goes to the project’s sessions. If the app does not know the project, for example after a ?session= link with no ?project=, back goes to the overview.
From the sessions list, back goes to the overview.
Each time back goes to the overview, from the sessions list or from a detail with no project, it clears the project scope. Only back from Insights keeps the scope.

Use ↓/J and ↑/K to move through table rows, and Enter or Space to open one. See Keyboard shortcuts.