Show HN: Token-saviour – agent skill from benchmarking 9 token-saving tools

A developer released token-saviour, an agent skill that routes coding tasks to the most token-efficient tool based on a benchmark of nine tools, achieving up to 69.6% token reduction on comprehension tasks. The skill classifies tasks by layer—code reading, command output, prose, or code writing—and selects the best tool per layer, with validated picks including serena, rtk, caveman, and Ponytail.

Spend tokens where they matter. An agent skill that routes every coding task to the most token-efficient tool for the layer it stresses — instead of reflexively reading whole files, dumping raw command output into context, or writing more code than asked. Token cost has four independent layers , and a different tool owns each. token-saviour picks one winner per layer — the best measured combination from a 9-tool benchmark https://github.com/vagkaratzas/token-consumption-benchmark on a realistic Python codebase: | Layer | Tool | Measured | |---|---|---| Code-read input symbols, callers, call paths, architecture | | −66% alone — the dominant cost input tests, builds, git, grep, listings rtk https://github.com/rtk-ai/rtk prose output chatty replies, write-ups caveman https://github.com/juliusbrussee/caveman code output implementations you write Ponytail https://github.com/DietrichGebert/ponytail Stacked serena + rtk + caveman : −69.6% total tokens on the comprehension suite. For code-generation work, swap caveman → Ponytail ≈ −64% . The picks were re-validated 2026-07 against newer entrants — archex, Pare, lazy-cat — and every incumbent held its layer. The runner-ups, the niches where they flip e.g. Pare's structured pytest for test-dominated loops , and the full evidence live in skills/token-saviour/references/ /vagkaratzas/token-saviour/blob/main/skills/token-saviour/references . /plugin marketplace add vagkaratzas/token-saviour /plugin install token-saviour@token-saviour Or as a plain personal skill, no plugin system involved: git clone https://github.com/vagkaratzas/token-saviour mkdir -p ~/.claude/skills cp -r token-saviour/skills/token-saviour ~/.claude/skills/ codex plugin marketplace add vagkaratzas/token-saviour codex plugin add token-saviour@token-saviour In Codex the skill is invoked with @token-saviour . The VS Code Codex extension and the Codex app read AGENTS.md , which this repo ships — so it also works from the repo root with no setup, and cp AGENTS.md ~/.codex/AGENTS.md makes the always-on rules global. Copy AGENTS.md compact, always-on ruleset or skills/token-saviour/SKILL.md full playbook into whatever instruction file your agent reads. Classifies the task by the layer it stresses: reading code, reading command output, writing prose, or writing code. Routes to that layer's tool with concrete commands serena MCP calls, rtk proxies, caveman terse mode, Ponytail rules — and degrades gracefully to plain Read/Grep/Bash when a tool isn't installed install/verify commands in . references/tool links.md Refuses anti-patterns : two code-read tools at once, rtk for comprehension, caveman on code, Ponytail on prose, tooling-up trivial one-line lookups. Announces what it used : 🪙 token-saviour: serena + rtk + caveman . serena — uv tool install -p 3.13 serena-agent — the one code-read tool LSP symbols; also does semantic edits/renames . rtk — brew install rtk or cargo install --git https://github.com/rtk-ai/rtk — add only for noisy command loops. caveman — see repo https://github.com/juliusbrussee/caveman — add only when prose brevity is the bottleneck. Ponytail — /plugin marketplace add DietrichGebert/ponytail — add only when code-generation work is the bottleneck. All numbers come from token-consumption-benchmark https://github.com/vagkaratzas/token-consumption-benchmark : real tools, real artifacts, one tokenizer tiktoken o200k base , per-task tables, and honest limitations modeled-not-metered, small clean codebase, single run . Summary: references/benchmark results.md /vagkaratzas/token-saviour/blob/main/skills/token-saviour/references/benchmark results.md . MIT — see LICENSE /vagkaratzas/token-saviour/blob/main/LICENSE .