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
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,
settings.installSection, locale.register, and session/event for the message
switch. The browser half draws its card into the public settings.plugin.item
slot and 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.
