YOUR AI'S STARTING POINT / macOS
Your context.
Before your
prompt.
Your coding agent starts with more than a blank slate. See the tokens Claude Code and Codex bring into a session—before the real work begins.
macOS 14+ · Apple silicon · Apple-notarized
STARTUP CONTEXT
INTERACTIVE EXAMPLESelect a category to isolate its share. Example data; your scan will differ.
01 / RUNTIMENative macOS
02 / SOURCE OF TRUTHCLI-reported totals
03 / RECORD KEEPINGLocal scan history
04 / SETUPYour existing CLI sign-in
THE INVISIBLE STARTING LINE
A fresh session.
Already carrying
your whole setup.
System instructions. Memory files. Tool definitions. Skills. Your agent has context before it has your task.
Context Tracker is a native Mac app for measuring that startup footprint. Choose a local repository, run a scan, and inspect the total the CLI reports. See Claude Code's category breakdown, then use recorded scans to understand how your setup changes.
How Claude Code uses contextONE REPOSITORY. ONE CLEAR READOUT.
Measure. Inspect. Compare.
- 01
Choose your repository.
Pick a folder on your Mac. Context Tracker uses the Claude Code CLI you already have installed and signed in.
local repository - 02
Let the tools report.
One Claude Code probe reads startup context. If Codex is installed and signed in, an optional read-only probe adds its own total.
Claude /context + Codex probe - 03
Follow the footprint.
Inspect the Overview, then revisit recorded scans in Trends and Compare. Keep up to 200 scans locally and clear them from Trends.
Overview → Trends → Compare
MEASUREMENTS WITH THEIR RECEIPTS
Know what the numbers mean.
# Ask the CLI for its startup context
claude -p "/context"
# Inspect the result in Context Tracker
session_total CLI-reported
categories CLI-reported
file_shares local estimatesThe app reads the tool's report. It does not reconstruct the total with its own tokenizer.
| Measurement | Claude Code | Codex |
|---|---|---|
| Session total | CLI-reported | CLI-reported |
| Context band | Included | Included |
| Categories | CLI-reported | Not provided |
| Probe | /context | Read-only session |
| CLI required | Yes | Optional |
Local instruction-file shares are estimates. Context bands are the app's interpretation, not a quality score from the model provider.
SMALL FOOTPRINT. CLEAR BOUNDARIES.
Your history stays
on your Mac.
No Context Tracker account.
No telemetry. No stored credentials.
Recorded history contains only a repository identifier, timestamp, tool, session total, context-window size, and category totals. It keeps the newest 200 scans in one local file.
Instruction-file contents, scan file paths, session IDs, and CLI credentials are never saved to history. Delete the history with Clear Recorded Data in Trends.
The probes use your signed-in CLIs and their network connections. The optional Codex probe sends the folder's instruction files to OpenAI. Provider data policies still apply. Local history does not mean the AI tools run offline.
A FEW DETAILS
Before your first scan.
What is startup context?
Startup context is the information an AI coding tool starts with before your task develops: system instructions, memory, skills, and tool definitions. Context Tracker reads the tool's own report so you can inspect that initial footprint for a local repository.
What do I need to run Context Tracker?
A Mac with macOS 14 or later and the Claude Code CLI installed and signed in. The current download is for Apple silicon. You also need a network connection. Install and sign in to the Codex CLI if you want the optional Codex probe.
Does a scan use my AI allowance?
The Claude Code probe reads /context without a model turn. The optional Codex probe runs a real read-only session and uses a small amount of your Codex allowance. Provider behavior and limits can change.
Can I compare Claude Code and Codex?
Yes. Recorded history identifies the tool for each scan, and Trends and Compare use those records. Each tool reports its own total and context window. Claude also supplies categories; Codex does not. These are startup-footprint measurements, not a benchmark of model quality.
Does it change my code or optimize my prompts?
No. Context Tracker is a measurement workspace. It shows you the reported startup footprint and local file estimates. It does not rewrite instructions, recommend changes, or modify your repository.
Is my repository uploaded to Context Tracker?
Context Tracker has no upload service, account, or telemetry. Scan history stays on your Mac. The probes run your existing Claude Code and optional Codex CLIs, which connect to their providers according to your configuration and the providers' policies.
START WITH A CLEARER PICTURE
Meet your
starting context.
One local repository. A measurable starting point.
Download Context TrackermacOS 14+ · Apple silicon · Apple-notarized DMG
Open the DMG. Drag Context Tracker into Applications.
Launch the app and choose your repository.