denki (電気)

Control TP-Link Kasa and Tapo devices from your terminal over the local network. Switch plugs, adjust supported lights, read energy usage, and record measurements for shell scripts or spreadsheets. 電気 means “electricity” in Japanese.

Documentation & interactive demo · Supported devices · Troubleshooting

Install

Install the current tagged release with Rust 1.99 or newer:

cargo install --git https://github.com/kahwee/denki --tag v0.1.1 --locked
denki --version
denki --help

GitHub releases currently provide source archives, not prebuilt executables. Denki is not published on crates.io. Cargo installs into ~/.cargo/bin; ensure that directory is on PATH. To update, repeat the command with the new tag. For development, clone the repository and run cargo install --path . --locked.

Your computer must be able to reach the device on the local network. Guest Wi-Fi and client isolation can block discovery and control. Start with info and doctor before issuing commands that change a device's state.

Connect your first device

Kasa

Discover devices and use an alias from the results:

denki scan
denki aliases
denki info "desk plug"
denki doctor "desk plug"
denki on "desk plug"
denki off "desk plug"

Replace desk plug with your device's alias. Scan saves discovered Kasa devices and their identities, preserving your names when a later scan finds a changed IP.

Tapo P125

Add the plug's IP and save the TP-Link account credentials associated with it. The example IP is a placeholder; login prompts for your password.

denki alias "tapo plug" 192.0.2.50 --tapo
denki login "you@example.com"
denki info "tapo plug"
denki on "tapo plug"
denki off "tapo plug"

--tapo (also spelled --tpap) automatically negotiates TPAP or KLAP. It does not force TPAP or change the app's Third-Party Compatibility setting. Existing --klap aliases keep Denki's original KLAP client; use that mode for other registered Tapo models. See Tapo setup and limitations.

Tapo scan probes saved addresses. Use denki scan --tapo-target 192.0.2.50 to probe an additional address. Commands accept aliases or IPs: a saved IP uses its registered protocol, while an unknown IP defaults to Kasa.

Energy and automation

On an energy-capable device, inspect a reading or record 12 samples as CSV:

denki energy "desk plug"
denki energy "desk plug" --json
denki energy watch "desk plug" --interval 5 --count 12 --format csv > energy.csv

Use --format jsonl for streaming JSON, or omit --count to record until Ctrl-C. Use --json for a versioned JSON result; with energy watch, it selects one JSONL record per sample. Do not combine --json with --format csv. The energy guide explains units, supported readings, and failed samples. P125 does not support energy monitoring in Denki.

Preview a group before switching its matching devices:

denki group off "office" --dry-run
denki group off "office"

The dry run lists targets without contacting devices.

Supported today

Support depends on the model, firmware, and connection mode.

Connection	Available in Denki	Hardware evidence
Kasa	Power, lighting, energy, outlets, and device settings, depending on model	Selected models; see the support table
Tapo `--klap`	Power; energy on registered energy-capable models	P125 power verified; other registered models unverified
Tapo `--tapo` / `--tpap`	P125 info, doctor, on/off/toggle, and group power	P125 info and on/off readbacks verified; toggle and this adapter's KLAP path unverified

Automatic-mode P125 tests used hardware 1.0 and firmware 1.4.0 Build 260803 Rel.232153. That adapter does not expose energy, schedules, timers, lighting, cameras, or hubs. Broader upstream support does not imply Denki support. Exact capabilities and verification status live in devices.toml and the support guide.

Common tasks

Goal	Command
Check a device and its capabilities	`denki doctor "desk plug"`
Set brightness on a supported light	`denki dim "desk lamp" 50`
List a power strip's outlet numbers	`denki outlets "desk strip"`
Control outlet 2 on a power strip	`denki on "desk strip" 2`
Save a Kasa IP when discovery is blocked	`denki alias "desk plug" 192.0.2.42`
Find a command's options	`denki <command> --help`

Replace the example names and 192.0.2.x addresses with your own devices. An unknown IP defaults to Kasa; use a saved --tapo or --klap alias for Tapo. Credentials can be saved with denki login EMAIL; omit the password so it is prompted rather than recorded in shell history. See the credential guide for details.

Documentation and development

The normal test suite runs offline. Live power tests require explicit targets and verify restoration of the starting state.

Credits and license

Automatic TPAP/KLAP communication uses Mihai Dinculescu's tapo library. Denki adds CLI commands, aliases, capability checks, and integration tests. His TPAP article explains the protocol and compatibility setting.

Denki is MIT licensed. Dependencies retain their respective licenses.

CI maintenance

GitHub Actions maintenance covers workflows, parallel checks, action versions, and weekly updates.

denki 0.1.1