dsh-ponytail

Your agent adds a cache class, a config flag, and a factory for one product. This plugin makes it stop and write the one line that works instead.

The ladder: question whether the thing needs to exist, reuse what is already in the repo, then the standard library, then the platform, then an installed dependency, then one line. Stop at the first rung that holds.

Adapted from DietrichGebert/ponytail (MIT). "He says nothing. He writes one line. It works."

What you get

• The ladder on every request. While any level except off is active, the mode-filtered ruleset joins the system prompt.
• Six skills the skill tool can load, so they also appear as /ponytail-review, /ponytail-audit, … in the composer: ponytail, ponytail-review, ponytail-audit, ponytail-debt, ponytail-gain, ponytail-help.
• Two ways to switch level. The model calls the ponytail tool; you type /ponytail <level> or just say stop ponytail.
• A settings card and a composer chip, so the level is visible without opening Settings.
• No unrequested abstractions, no boilerplate. Deletion over addition, boring over clever.

Install

Install it as a bundle. dsh plugin add … mounts the row from the package's own patch layer, which is what the settings editor can write to. A row added with --patch is an overlay: it disappears at the next start, and the Plugins card cannot save into it — the editor refuses a write an overlay would win.

dsh plugin --profile web add github:maci0/dsh-ponytail   # untagged spec tracks main

The package declares dsh.bundle, so dsh plugin add appends it to dsh.profile.bundles and the row in its own cordis.patch.yml applies as a layer. Bundle layers compose at boot, so restart dsh web. To pick up a newer commit later, run dsh plugin --profile web update dsh-ponytail and restart again.

Do not also paste that id: ponytail row into your profile's own cordis.patch.yml: insert does not dedupe ids, and a second row mounts the plugin twice.

Try it

/ponytail ultra   -> Ponytail level: ultra (was full).
/ponytail         -> Ponytail level: ultra.
/ponytail off     -> Ponytail off (was ultra). Normal behavior.

Then ask for the work. This is the full example from the skill itself:

> Add a cache for these API responses.

`@lru_cache(maxsize=1000)` on the fetch function. Skipped custom cache class,
add when lru_cache measurably falls short.

Model side, the tool takes one optional argument: {"mode": "lite"} sets and persists a level, and calling it with no argument reports the current one.

Typing stop ponytail or normal mode as an ordinary message has the same effect as /ponytail off, and it lands on the turn that carried it. Only the human's own words count — injected context riding the same event stream cannot toggle the level, and the message must be the command: "add a normal mode toggle" is left alone.

Levels

Level	Behavior	Persisted
lite	Build what was asked, name the lazier alternative in one line.	yes
full	The ladder enforced. Default.	yes
ultra	YAGNI extremist: challenge the requirement before building it.	yes
review	Over-engineering review; points at the ponytail-review skill.	no — session only
off	No injection. Normal behavior.	yes

The four persistable levels live in the ponytail settings namespace, so the card, the chip, the tool, and /ponytail always agree and the choice survives a restart. review stays session-only because it is a review mode, not a level a deployment should start in; the tool and the command still accept it.

Lazy is not negligent. Understanding the problem, trust-boundary validation, data-loss handling, security, and accessibility are never on the chopping block.

Configure

Field	Default	Meaning
defaultMode	full	Startup level. Must be off, lite, full, or ultra.

The exported Config schema defaults the field, so a row that omits defaultMode starts in full. The user's settings namespace overrides it once a level is chosen in the card or by /ponytail. An invalid level fails while the plugin loads rather than quietly doing the wrong thing: the loader validates the row against the exported schema.

To set the startup level from the environment, override the row in your profile's cordis.patch.yml with a !!js expression (same id, which replaces the row's whole config):

- id: ponytail
  config:
    defaultMode: !!js process.env.PONYTAIL_DEFAULT_MODE ?? 'full'

How it works

The host half mounts through public Cordis extension points — systemPrompt.section, skills.registerProvider, tools.register, commands.register, loader/volatile-update (the settings document writes the row's volatile defaultMode), and session/event for the message switch. The browser half draws its card into the public plugins.row.config slot from configForms, registers its copy through locale.register, and draws its chip into conversation.input.left, so this plugin needs no client change of its own.

The entry point is the built lib/index.js (declarations in lib/types/); npm run build regenerates it from src/. lib/client.js is hand-authored plain JavaScript — the client module system serves it as a lazy-CJS factory on window.__ModuleLoader__ because the package exports ./client, and it is not built. Skills come from skills/<name>/SKILL.md with frontmatter parsed by yaml; the provider takes its rank and name grammar from @deepseek-ai/dsh-skill, projects disable-model-invocation, user-invocable, and whenToUse, and settles on the lookup's abort signal. Tools use defineTool from @deepseek-ai/dsh-tools and forward exec.signal. Only skills/ponytail/SKILL.md is the source of truth for the ruleset; this README keeps no second copy.

What it does not do

• It does not skip comprehension. The ladder shortens the solution, never the reading. The skill says so in its own text.
• The level is process-wide. One prompt section, one namespace value: every agent in the process shares it.
• External subagents ignore it. In-process children inherit the ruleset, but subagent-claude-code and subagent-codex spawn their own CLI with its own system prompt, and no harness extension point wraps a spawn.
• Two locales. The card and the chip ship en and zh; any other locale falls back through the service's own chain.
• Host source edits need npm run build and a restart, because the Loader loads lib/index.js and a bundle layer composes at boot.
• Browser-half edits need a page refresh.
• A level change is not a session event. A replayed session shows the ruleset each request already carried.

Development

npm install         # real install
npm run build       # tsc -p tsconfig.build.json -> lib/index.js + lib/types/
npm test            # node --test tests/*.test.ts (Node ^22.19 || >=24, no build step)
npm run typecheck   # tsc -p tsconfig.json

The suite covers level normalization and filtering, the fake-host surface, the skills provider, the client card, and a real Cordis composition mount next to the real skill registry. To uninstall, run dsh plugin --profile web remove dsh-ponytail; that removes the dependency and the bundle layer together.

Attribution and license

MIT. Skill content and mode semantics: © DietrichGebert (ponytail). DSH port: see LICENSE.

The six skills/*/SKILL.md files are verbatim copies, so they carry upstream's figures and citations rather than this package's. /ponytail-gain therefore reports the original five-task single-shot benchmark — 80–94% fewer lines, 47–77% cheaper, 3–6× faster — which upstream's own README has since revised to roughly 54% fewer lines, 20% cheaper and 27% faster on its agentic benchmark; and its Source: line names benchmarks/, which this package does not ship.