keel — Spec-Driven Development Discipline Skill Pack
Write the spec first, then the code. Turn "don't ship it broken" from a slogan into skills, tooling, and gates.
keel is a self-contained pluginized skill pack: five skills (Anchor → Spec → Probe → Build → Audit) constrain the agent's coding behavior, three tools provide spec generation and discipline review, and template variants adapt to task size. It works with plugin-everything harnesses such as dsh (DeepSeek Harness), and can also be used standalone without a harness.
Why you need it
The three main causes of coding failure:
- Missing spec — you start with vague requirements, and wrong implementation direction costs the most rework;
- Unverified assumptions — treating "I assumed" as "it's a fact" builds the plan on quicksand;
- Engineering out of control — doing too much (over-engineering) or drifting (scope creep).
keel's response: write the spec and verify assumptions first; no implementation until the spec passes the gates. During implementation, use the rules to prevent over-engineering and change requests to prevent scope creep. Before delivery, audit each acceptance criterion one by one. Discipline is enforced through skills/prompts that constrain agent behavior and through tools that provide deterministic checks — it does not rely on human self-discipline.
Five-step discipline loop
| Step | Skill | Action | Artifact | Gate |
|---|---|---|---|---|
| 1 Anchor | keel-anchor | Three boundary questions: what to do, what not to do, what success looks like | Three sentences | All three sentences verifiable |
| 2 Spec | keel-spec | Pick a template by size and generate the spec | SPEC.md | keel_review zero errors |
| 3 Probe | keel-probe | Register assumptions, flag risks, verify high-risk ones first | ASSUMPTIONS.md | All [High] assumptions resolved (enforced by KEEL-0303) |
| 4 Build | keel-build | Implement per the spec, follow the ten rules and the scope guardrails | Code | Spec frozen, changes go through change requests |
| 5 Audit | keel-audit | Check acceptance criteria one by one, record deviations and retro | AUDIT.md | No unaddressed ❌ (enforced by KEEL-0403) |
Failure post-mortems follow the same discipline: write a failure-cause spec first, verify assumptions, then fix.
Quick start
Option 1: Plug into dsh (pluginized harness)
- Put this directory into your project, or copy it anywhere;
- Create a
cordis.ymlpatch (you can copycordis.example.ymlfrom the repo root) pointing to this plugin's entry:
- insert:
- id: keel
name: '/absolute/path/spec-driven/src/index.ts'- Start the harness and load the patch:
dsh web --patch ./cordis.ymlOnce loaded, the model gains three tools (keel_catalog, keel_spec, keel_review) and five skills (keel-anchor, keel-spec, keel-probe, keel-build, keel-audit). See docs/INTEGRATION.md for details.
Option 2: Bare-metal CLI (no harness)
node src/cli.ts catalog
node src/cli.ts scaffold spec SPEC.md "--title=Example" "--goal=Goal" "--in_scope=- behavior" "--out_of_scope=- not doing" "--requirements=- R-01" "--acceptance=- AC-01" "--verification=command"
node src/cli.ts review SPEC.mdValues containing spaces must be quoted (as above). review exits with code 0 when there are no errors (usable as a CI gate) and 1 when errors exist. Zero dependencies; runs directly on Node ≥ 22.18.
Installing in DSH
keel ships a dsh.bundle manifest (cordis.patch.yml, referenced from package.json), so it installs and activates in one command:
dsh plugin --profile demo add github:JohnXu22786/spec-drivenThe bundler inserts a plugin row (name: keel) into the profile and dsh resolves the package entry (src/index.ts), registering the three tools and five skills on load. Manual local loading via a cordis.yml patch still works (see docs/INTEGRATION.md).
Tool interface
| Tool | Purpose |
|---|---|
keel_catalog | List the skills and templates (routing entry) |
keel_spec | Generate spec-class files from a template (template/path/fields args; rejects the whole call if any field is missing) |
keel_review | Review SPEC/ASSUMPTIONS/AUDIT files; outputs a report with rule IDs and line numbers |
Spec templates (with variants)
| Template | Size | Use |
|---|---|---|
spec.minimal | Micro task | Single file, single behavior, done in under half an hour |
spec | Standard | Regular feature tasks |
spec.feature | Large task | Involves interfaces, data, and error paths |
assumptions | — | Assumption register (risk levels + verification conclusions) |
audit | — | Acceptance audit table (result + evidence + deviation + retro) |
change-request | — | Change request (the only entry for scope changes after the spec is frozen) |
Configuration
Passed via the config field of the host patch line (defaults are used without a harness):
{
"strictness": "relaxed", // relaxed | strict (strict upgrades warnings to errors)
"requireAssumptions": true, // require an ASSUMPTIONS*.md file in the same directory when reviewing a spec
"maxFindings": 100 // cap on findings per review report (1–1000)
}Invalid configuration fails at load time with a message containing fix guidance.
Documentation index
- docs/METHODOLOGY.md — methodology overview: five-step discipline loop, the ten rules against over-engineering, scope-creep guardrails, review rule list (KEEL-*)
- docs/INTEGRATION.md — dsh integration: loading, registration interface, the three ways to load skills, unload and reload
- docs/PLANNING_BRIDGE.md — bridging to planning/task-breakdown skills: how spec artifacts feed into planning
- examples/ — good examples (spec/assumptions/audit) and counter-examples (demonstrating the review engine's findings)
Development
npm test # node --test all tests (zero test dependencies)
npm run typecheck # tsc --noEmit
npm run cli # bare CLIRunning tests and type checks requires Node ≥ 22.18; npm install only installs dev-time type packages (typescript, @types/node); zero runtime dependencies.
License
MIT, see LICENSE.
