README.md

claude-statusline-rust-tinybinary

Tiny Rust status line renderer for Claude Code.

Kickstarter

Claude Code status lines are most useful when they are fast and dense. This tool replaces shell pipelines like jq | awk | date with one tiny Rust binary that reads Claude's JSON once and prints one line.

Fast start:

make install && ./add-to-claude-settings.py --full --compact

That writes this kind of status line:

Opus 4.7|max|T|c68k/200k:34%|w41%|r2d7h|$2.31|v2.1.201

For capture while debugging missing fields such as week or reset:

make install && ./add-to-claude-settings.py --full --compact --debug-log-dir ~/.cache/claude-statusline-rust-tinybinary

The helper is optional. It is a portable Python 3 script using only the standard library, and the manual settings.json examples below show the exact configuration it writes.

Why

Claude Code statusLine can run a command, passes JSON session data to that command on stdin, and displays stdout. This binary reads stdin once, parses the JSON once, and prints one compact line.

The point is lower startup and processing overhead than Bash pipelines that invoke tools such as cat, jq, awk, grep, and date. The implementation is intentionally simple and dependency-light.

Styles

claude-statusline-rust-tinybinary --style default
claude-statusline-rust-tinybinary --style full
claude-statusline-rust-tinybinary --style weekly
claude-statusline-rust-tinybinary --style debug
claude-statusline-rust-tinybinary -s default
claude-statusline-rust-tinybinary --full
claude-statusline-rust-tinybinary --full --reset-status=off
claude-statusline-rust-tinybinary --full --version-status=off
claude-statusline-rust-tinybinary --full --compact
claude-statusline-rust-tinybinary --weekly -c
claude-statusline-rust-tinybinary --version

Default style is default.

--style full includes the Claude Code version from status-line JSON at the end by default. Use --version-status=off to hide it. The standalone --version flag prints this helper binary's version instead.

--compact or -c is a representation modifier. It always keeps the selected style's fields and only renders each field in its compact form, removing spacing, long labels, and visual separators:

Opus 4.7|max|T|c34%|w41%|r2d7h
Opus 4.7|max|T|c68k/200k:34%|w41%|r2d7h|$2.31|v2.1.201
Opus 4.7|c34%|w41%|r2d7h

For custom ordering, use --format:

claude-statusline-rust-tinybinary --format '%M|%E|%T|%w|%r|%C|%c|%v'

Format tokens:

• %M model
• %E effort
• %T thinking
• %w weekly percentage
• %r reset status
• %C context summary
• %c cost
• %v Claude Code version from status-line JSON
• %% literal percent sign

--reset-status=off hides reset output in built-in styles and makes %r render as empty in custom formats. --version-status=off hides version output in --style full and makes %v render as empty in custom formats.

Example output

Opus 4.7 │ e:max │ T:T │ ctx ███░░░░░░░ 34% │ week 41% reset:2d7h
Opus 4.7 │ effort:max │ think:T │ ctx ███░░░░░░░ 68k/200k 34% │ week 41% reset:2d7h │ $2.31 │ v2.1.201
Opus 4.7|max|T|c68k/200k:34%|w41%|r2d7h|$2.31|v2.1.201
Opus 4.7|max|T|c68k/200k:34%|w41%||$2.31|v2.1.201

Sample input:

{
  "model": {
    "id": "claude-opus-4-7",
    "display_name": "Opus 4.7"
  },
  "version": "2.1.201",
  "effort": {
    "level": "max"
  },
  "thinking": {
    "enabled": true
  },
  "context_window": {
    "used_percentage": 34.2,
    "total_input_tokens": 68000,
    "context_window_size": 200000
  },
  "rate_limits": {
    "seven_day": {
      "used_percentage": 41.4,
      "resets_at": 1898780400
    }
  },
  "workspace": {
    "current_dir": "/home/greg/project"
  },
  "cost": {
    "total_cost_usd": 2.31
  }
}

Install

cargo install --path . --locked # or `make install`

Or build locally:

cargo build --release

Configure Claude Code

Fast helper:

./add-to-claude-settings.py --help
./add-to-claude-settings.py --full --compact
./add-to-claude-settings.py --style default --debug-log-dir ~/.cache/claude-statusline-rust-tinybinary

The helper updates ~/.claude/settings.json, preserves other top-level settings, and creates a timestamped backup when replacing an existing file.

Using PATH:

{
  "statusLine": {
    "type": "command",
    "command": "claude-statusline-rust-tinybinary --style default",
    "padding": 0
  }
}

Full style with compact presentation:

{
  "statusLine": {
    "type": "command",
    "command": "claude-statusline-rust-tinybinary --style full --compact",
    "padding": 0
  }
}

Using a direct path:

{
  "statusLine": {
    "type": "command",
    "command": "~/.cargo/bin/claude-statusline-rust-tinybinary --style full",
    "padding": 0
  }
}

With debug capture enabled:

{
  "statusLine": {
    "type": "command",
    "command": "claude-statusline-rust-tinybinary --style full --compact --debug-log-dir ~/.cache/claude-statusline-rust-tinybinary",
    "padding": 0
  }
}

Debug capture writes one JSONL file per status-line invocation, named like:

~/.cache/claude-statusline-rust-tinybinary/260704-181530-12345.jsonl

Each file contains the JSON payload Claude Code passed on stdin. If the input is malformed, the file contains a small record with bad_json and raw fields. This is useful when week or reset shows n/a, because the captured payload shows whether Claude Code actually sent rate_limits.seven_day.used_percentage and rate_limits.seven_day.resets_at.

Fields can be null or missing, especially early in a session, after compaction, or when a model or plan does not provide a field. Missing values are handled with compact fallbacks.

Fields used

• model.display_name
• model.id
• effort.level
• thinking.enabled
• context_window.used_percentage
• context_window.total_input_tokens
• context_window.context_window_size
• rate_limits.seven_day.used_percentage
• rate_limits.seven_day.resets_at
• workspace.current_dir
• cwd
• cost.total_cost_usd

The weekly rate limit is read from rate_limits.seven_day.used_percentage; it is not inferred from cost or local logs. Five-hour usage is intentionally not shown in the default layouts.

Performance rationale

This is a small compiled CLI with one runtime dependency, serde_json. It avoids a shell pipeline of repeated process startup and repeated parsing. The release profile favors compact binaries for fast cold startup:

[profile.release]
opt-level = "s"
lto = "thin"
codegen-units = 1
panic = "abort"
strip = "symbols"

There is no TUI, daemon, background service, network call, async runtime, logging framework, or config file.

Development

make
make build
make test
make integration-tests
make size
make sample
make install
make uninstall
make clean

make integration-tests runs the Docker/tmux Claude Code integration harness and removes its container when done. Use make integration-tests-keep-docker-artifacts to keep the container for inspection, and make clean-docker-artifacts to remove kept artifacts. Details are in integration-tests/README.md.

Manual smoke test:

echo '{"model":{"display_name":"Opus"},"context_window":{"used_percentage":34}}' \
  | target/release/claude-statusline-rust-tinybinary --style default

Expected shape:

Opus │ e:na │ T:? │ ctx ███░░░░░░░ 34% │ week n/a

References

• Claude Code status line docs: statusLine runs a command, receives JSON on stdin, and displays stdout.
• Cargo release profiles: opt-level, lto, codegen-units, panic, and strip.