c2 — Concept2 Logbook CLI

A CLI tool for syncing and analyzing rowing data from your Concept2 Logbook.

Install

go install github.com/richhaase/c2/cmd/c2@latest

Or pin a release:

go install github.com/richhaase/c2/cmd/c2@v0.5.0

Binaries for macOS and Linux are also attached to each release.

To build from a checkout:

git clone https://github.com/richhaase/c2.git
cd c2
make install

Quick Start

# Configure token and goals
c2 setup

# Sync workouts
c2 sync

# Check your progress
c2 status

Usage

Setup

Configure your token and goal settings:

c2 setup

Get your personal access token from log.concept2.com under Settings → Developer. The setup wizard will prompt for your token, goal target, and date range.

Sync Workouts

Pull new workouts from the Concept2 API:

c2 sync

View Workouts

# Show last 10 workouts
c2 log

# Show last 25 workouts
c2 log -n 25

Interval workouts are tagged with [IVL rest M:SS.S] so they're visually distinct from continuous pieces. The rest duration is surfaced because, for interval workouts, the displayed time (time_formatted) is elapsed time including rest, while the displayed pace is correctly computed from work time only. For example:

04/11   5,000m   28:35.4   2:51.5/500m  24spm  112bpm  107df
04/11   3,000m   20:22.6   2:23.8/500m  30spm  152bpm  108df  [IVL rest 6:00.0]

The second row is 6x500m with ~1 min rest between reps: 20:22.6 elapsed = 14:22.6 work + 6:00 rest. The 2:23.8/500m pace is the work pace.

Goal Progress

Track progress toward your distance goal:

c2 status

Training Trends

View weekly trends for pace, volume, stroke rate, and heart rate:

# Last 8 weeks (default)
c2 trend

# Last 12 weeks
c2 trend -w 12

HTML Report

Generate a self-contained HTML progress report. Coaching content from the store renders automatically when present: the latest narrative (as "Coach's Report"), notes from the last 14 days, and the training-plan excerpt. c2 report --data emits the entire report as structured JSON (c2.report.v1) — the machine-readable twin of the HTML, for agents and custom rendering surfaces:

# Write to a temp file and open it in your browser
c2 report

# Custom output path
c2 report -o ~/Desktop/rowing.html

# Write the file but don't open it
c2 report --no-open

# Show more weeks of history
c2 report -w 16

Export Data

Export workouts to CSV, JSON, or JSONL:

# CSV to stdout
c2 export

# JSON format
c2 export -f json

# Filter by date range
c2 export --from 2026-01-01 --to 2026-03-01

# Pipe to file
c2 export -f jsonl > workouts.jsonl

The CSV export includes workout_type, rest_time_tenths, and rest_distance columns so interval workouts are fully distinguishable from continuous pieces without having to consult the full JSON export.

Workout Detail & Derived Stats

# Full detail for one workout: splits, stroke summary, comments
c2 show last
c2 show 118212501

# Derived analytics (the arithmetic, so coaches only interpret)
c2 stats weekly -w 12     # volume/pace/SPM/HR per week
c2 stats goal             # trajectory + projection
c2 stats splits last      # per-split pace/HR + shape (even/negative/positive)
c2 stats hr-pace -w 8     # avg HR by steady pace band, with early→late drift

All of these accept --json.

Coaching Data

The store holds coaching content alongside workout data, so any coach — human or AI, on any machine — reads and writes the same facts:

# Subjective report after a row (athlete voice, linked to the workout)
c2 note add --type subjective --workout last "felt slow early, opened up late"

# Coach observations and durable lessons
c2 note add --type lesson --author coach "HR cap is the rule, not pace"

# Review
c2 note list --since 2026-06-01
c2 note list --workout 118212501 --json
c2 show last                     # linked notes appear in workout detail

# Training plan and coaching playbook (whole-document set/show)
c2 plan set plan.md
c2 playbook show

# Dated coaching report narratives
c2 narrative add 2026-07-05 report.md
c2 narrative show

Notes are stored one file each for the most recent 7 days (safe under iCloud/ Dropbox sync), then automatically compacted into one archive file per year (c2 data compact runs after every sync). c2 data doctor validates the whole store.

Machine-Readable Output

log, status, trend, show, stats, and data info accept --json and emit a stable versioned envelope for scripts and AI agents:

{ "schema": "c2.status.v1", "generated_at": "2026-07-05T18:00:00.000Z", "data": { } }

export -f json emits the same envelope (c2.export.v1) with the full workout records under data.workouts. export -f jsonl stays one raw workout per line for streaming.

Data Store

Workout data and coaching data live in a single data directory, chosen during c2 setup and stored as data_dir in config. Point it at a synced folder (iCloud, Dropbox, a git repo) to share one store across machines — the config file with your API token always stays machine-local in ~/.config/c2/ (mode 600).

# Where is my data, and what's in it?
c2 data info

# Relocate the store (copies, verifies, updates config)
c2 data move ~/Documents/KnowledgeBase/c2-data

Setup validates the directory you pick: it creates it if missing (with confirmation), checks writability, adopts an existing c2 store it finds there, and refuses to save a path that fails validation.

Note: bare c2 prints help. Unknown commands error instead of falling through to a default.

Configuration

Config lives at ~/.config/c2/config.json. Created automatically on c2 setup.

{
  "data_dir": "~/.config/c2/data",
  "api": {
    "base_url": "https://log.concept2.com",
    "token": "YOUR_TOKEN"
  },
  "goal": {
    "target_meters": 1000000,
    "start_date": "2026-01-01",
    "end_date": "2026-12-31"
  },
  "display": {
    "date_format": "%m/%d"
  }
}

Development

make check       # fmt-check + vet + lint + race tests
make test        # tests only
make build       # build ./bin/c2
make run ARGS="log -n 5"

License

MIT — see LICENSE