tersio

✂️ Tersio — Token Saver & Usage Tracker

Token saver & usage tracker for coding agents: terse caveman replies, compact RTK shell output, lean Ponytail code, Headroom compression, pstack rigor, and a gain dashboard — one-command combos over one shared extension tree.

🎯 What this is, and why you would use it

Coding agents bill you per token. Three of the costs you never asked for:

• Replies carry filler. The same three sentences, plus a greeting, a hedge, a recap, and a "hope this helps".
• Shell output is noise. A failing test prints hundreds of lines to reach the four that matter.
• The rules repeat every turn. Your agent re-reads its instructions on every single turn.

Tersio installs into Oh My Pi, Pi, Pi-in-go, OpenCode, DeepSeek Harness, and Codex, and cuts those costs:

| Mode | What it does for you |

|---|---|

| 🪨 Caveman | Shorter replies. Answer first, filler gone, and code, commands, paths, and errors stay exact. |

| 🗜️ RTK | Condensed shell output, every signal kept. A failing test still names the test, the assertion, and the line. |

| 🧠 Ponytail | Leaner code. YAGNI: no feature, option, or abstraction nobody asked for, and the shortest diff that still works. |

| 🥔 pstack | Rigor mode. It applies a design principle when the moment fits, and owns the approach, the check, and the design. Opt-in, on its own switch. |

| 🍃 Headroom | Headroom shrinks tool output, file reads, and history. Opt-in; Tersio reads its savings and never turns it on for you. |

| 🧩 Combo | One command sets Caveman, RTK, and Ponytail, at three strengths. |

| 📊 Dashboard | What you spent, per model and per day. |

⚡ Getting Started

All install paths in one table, with update and remove commands: [INSTALL.md](./INSTALL.md).

Default (macOS/Linux) — one line. Installs the CLI via npm, then runs the main installer (scope + Combo preset menus) in the same pass:

curl -fsSL https://github.com/KurutoDenzeru/tersio/releases/latest/download/install.sh | sh

Windows — one line, the same pass through PowerShell:

irm https://github.com/KurutoDenzeru/tersio/releases/latest/download/install.ps1 | iex

Then run the CLI. Bare tersio opens a menu and asks which agent to install into:

tersio                      # menu — picks Oh My Pi, pi, OpenCode, Pi-in-go, DeepSeek Harness, or Codex
tersio install --host pi    # pi, non-interactive
tersio install --host omp   # Oh My Pi, non-interactive
tersio install --host opencode  # OpenCode, non-interactive
tersio install --host pig   # Pi-in-go (PiG), non-interactive
tersio install --host dsh   # DeepSeek Harness — mounts the bundle into every dsh profile
tersio install --host codex # Codex — plugin, MCP server, skills, prompt hook, and /prompts fallbacks

Or let each host install the package itself:

omp plugin install @krtclcdy/tersio
pi install npm:@krtclcdy/tersio
opencode plugin add @krtclcdy/tersio
pig install npm:@krtclcdy/tersio
dsh plugin --profile web add npm:@krtclcdy/tersio
codex plugin marketplace add KurutoDenzeru/tersio
codex plugin add tersio@tersio

One-off use without installing:

npm exec --yes --prefer-online --package=@krtclcdy/tersio@latest -- tersio install

Requirements

| Need | Detail |

|---|---|

| Host | [OMP](https://github.com/can1357/oh-my-pi), [pi](https://github.com/earendil-works/pi), [OpenCode](https://opencode.ai), [PiG](https://pi-in-go.dev), [DeepSeek Harness](https://github.com/deepseek-ai/deepseek-harness), or [Codex](https://github.com/openai/codex) — tersio install --host |

| Node.js | 20.12+ with npm. The CLI runs under Node |

| Bun | Optional. Preferred when on PATH, npm otherwise; also supplies SQLite in process |

| SQLite | Bun, Node 22.5+ node:sqlite, or the sqlite3 binary on PATH |

| OS | macOS, Linux, or Windows, native (install.ps1). WSL works too, installed from inside it |

📊 Dashboard

tersio dashboard opens a local page for usage, cost, tools, traces, and savings. Other pages cover Models, Providers, Costs, Carbon, Requests, Errors, Tools, and Projects.

Quick start (Recommended) is the place to see the whole setup workflow: the modes, the agents, and how one turn moves from prompt to output.