codexusage

See how much your OpenAI Codex sessions cost - broken down by day, month, or session - right from your terminal.

Inspired by @ccusage/codex, codexusage is a ground-up Rust rewrite built for users who need a significantly faster and lighter alternative to scan large session histories.

Install

cargo install codexusage

Quick start

# Daily usage summary
codexusage daily

# Monthly report as JSON
codexusage monthly --json

# Last 7 days only
codexusage daily --last-days 7

# Custom session directory
codexusage session --session-dir /path/to/sessions

Examples

Filter by date range:

codexusage daily --since 2026-03-01 --until 2026-03-31

Skip network and use cached pricing:

codexusage daily --offline

JSON output for scripts and dashboards:

codexusage daily --json

Watch mode

Monitor today's usage live in your terminal. The screen refreshes automatically and shows a rolling burn rate so you can see how fast tokens are being consumed:

codexusage watch

Custom refresh interval (default 5 seconds):

codexusage watch --interval 10

Sample output:

Current Day Codex Usage Watch
Date: 2026-03-11  Window: 60 minutes

+-----------+------------+----------------+
| Metric    | Today      | Burn Rate (/h) |
+-----------+------------+----------------+
| Input     |       450K |            56K |
| Cache     |       120K |            15K |
| Output    |        30K |             4K |
| Reasoning |        12K |             2K |
| Total     |       612K |            77K |
| Cost      |      $0.85 |          $0.11 |
| Updated   | 2026-03-11 |       14:32:23 |
+-----------+------------+----------------+

Watch mode does not support --json, --since, --until, or --last-days.

Options

Commands:

• daily - group usage by day
• monthly - group usage by month
• session - group usage by session
• watch - live current-day monitor with burn rate

Flags:

• --json - emit structured JSON instead of a table
• --since / --until - inclusive date filters
• --last-days N / -L N - show the last N calendar days (daily only)
• --timezone - IANA timezone for grouping
• --offline - use cached pricing, never hit the network
• --refresh-pricing - force a pricing refresh
• --session-dir - override session directory (repeatable)
• --threads N - scanner worker count
• --number-format full - show full token counts instead of K/M/B/T

--last-days cannot be combined with --since or --until.

By default, codexusage scans CODEX_HOME/sessions (or ~/.codex/sessions when CODEX_HOME is not set).

Sample output

Daily Codex Usage Report

+------------+--------------+-------+-------+--------+-----------+-------+-------+
| Date       | Model        | Input | Cache | Output | Reasoning | Total |  Cost |
+------------+--------------+-------+-------+--------+-----------+-------+-------+
| 2026-03-01 | TOTAL        |  120K |   30K |     8K |        4K |  158K | $0.20 |
|            |   gpt-5      |  120K |   30K |     8K |        4K |  158K | $0.20 |
+------------+--------------+-------+-------+--------+-----------+-------+-------+
| 2026-03-02 | TOTAL        |   90K |   20K |     6K |        2K |  118K | $0.03 |
|            |   gpt-5-mini |   90K |   20K |     6K |        2K |  118K | $0.03 |
|            | GRAND TOTAL  |  210K |   50K |    14K |        6K |  276K | $0.23 |
+------------+--------------+-------+-------+--------+-----------+-------+-------+

Pricing

Pricing data is cached locally and refreshed automatically when stale. Use --offline to skip network access entirely, or --refresh-pricing to force an update.

Live pricing refreshes use the system CA store through reqwest's Rustls backend. Minimal containers or stripped-down CI images may need a CA bundle such as ca-certificates installed for refreshes to succeed.

Performance

codexusage was built because @ccusage/codex became unusably slow on large session directories. The table below shows a side-by-side comparison on the same dataset.

Test environment: 4.4 GB across 7726 session files, Intel i7-1185G7 (8 logical CPUs).

Notes:

• @ccusage/codex was already cached by Bun; the one-time download is not counted.
• Results reflect this specific machine and dataset, not a universal guarantee.

Development

Build from source:

cargo build --release

Source builds require a working C toolchain and cmake because the reqwest TLS stack pulls in aws-lc-rs.

Quality commands:

just fmt
just clippy
just test
just bench