harness-discover

harness-discover is a command for Claude Code from kimsanguine/hplan. It costs 51 tokens per session (4,061 once invoked), scanned A, original, MIT.

An end-to-end discovery workflow for turning a product or coding-agent idea into a tested opportunity. It covers opportunity mapping, assumption analysis, AI cost estimation, the choice between building and buying, and validation planning.

In plain words
What is it for?
Use it to explore a new idea, question its assumptions, map the opportunity, estimate AI costs, compare building with buying an existing solution, or run selected discovery stages.
Why use it?
It helps investigate whether an idea is worth pursuing before detailed requirements or implementation. The workflow makes unclear assumptions, expected costs, and alternative solutions explicit.

Command for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is python3 hplan/scripts/decision_log.py hitl \.

Part of the hplan plugin — 8 skills, 11 commands, 4 agents shipped together

Good fit Use it to explore a new idea, question its assumptions, map the opportunity, estimate AI costs, compare building with buying an existing solution, or run selected discovery stages.

Compare 6 commands from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/kimsanguine/hplan
agentmods
npx agentmods add commands/kimsanguine/hplan/harness-discover

Made for: Claude Code.

Or install hplan, the plugin that ships this one along with the rest of its 8 skills, 11 commands, 4 agents.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for harness-discover

README.md
[![agentmods](https://agentmods.dev/badge/commands/kimsanguine/hplan/harness-discover/github.svg)](https://agentmods.dev/commands/kimsanguine/hplan/harness-discover)
Your own site
<a href="https://agentmods.dev/commands/kimsanguine/hplan/harness-discover"><img src="https://agentmods.dev/badge/commands/kimsanguine/hplan/harness-discover/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for harness-discover

Your own site · 80×15
<a href="https://agentmods.dev/commands/kimsanguine/hplan/harness-discover"><img src="https://agentmods.dev/badge/commands/kimsanguine/hplan/harness-discover.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 51 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 4,061 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00051 $0.04061
Opus 5 $0.00026 $0.02031
Sonnet 5 $0.00010 $0.00812
Haiku 4.5 $0.00005 $0.00406

Measured 8d ago against content hash c99ec47ed5dd, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

harness-discover scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 8d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

hplan/commands/harness-discover.md · 356 lines

How it starts

The opening of the file, as written. The whole thing — 356 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/harness-discover

기회 발굴 전체 워크플로우 — 아이디어 → 검증된 기회 + 비용 추정 + 빌드/바이 결정 + 가정 검증

Phase 0 — 가정 심문 (선택적 진입점)

아이디어가 있지만 "만들 가치가 있나"라는 가정이 불분명할 때 먼저 이 단계를 거치세요. Phase 1(Opportunity Mapping)은 가정이 어느 정도 정리된 상태에서 시작할 때 더 유효합니다.

진입 조건: 다음 중 하나라도 해당되면 Phase 0부터 시작합니다.

  • 아이디어는 있지만 "왜 이게 필요한가"에 대한 가정이 불분명함
  • 이전에 비슷한 아이디어를 시도했다가 실패한 경험이 있음
  • "사람들이 쓸 것 같다"는 직관 외에 근거가 약함

Phase 0 실행: /socratic-question [아이디어]

socratic-question은 6가지 질문 유형(명료화·가정·증거·관점·함의·메타질문)으로 당신의 가정을 심문하고, "사고 검증 질문 세트" 1장을 만듭니다.

Phase 0 완료 기준: "누구의 / 무슨 문제를 / 무엇으로 / 무엇은 빼고 푼다" 가 한 문장으로 나오면 → Phase 1으로 넘어가세요 (/harness-discover [아이디어])

Phase 0 생략: 가정이 이미 명확하거나 빠른 탐색이 목적이라면 바로 Phase 1부터 시작해도 됩니다.


Routing

Parse $ARGUMENTS for a --mode flag before proceeding:

Flag Execution
--mode socratic Phase 0 — socratic-question 실행 후 종료
--mode opp Phase 1만 실행 후 종료
--mode assumptions Phase 2만 실행 후 종료
--mode cost Phase 3만 실행 후 종료
--mode build-or-buy Phase 4만 실행 후 종료
--mode validate Phase 5만 실행 후 종료
플래그 없음 Phase 1 → 2 → Checkpoint → 3 → 4 전체 실행 (Phase 5 제외)

The remaining text after the flag is the target idea. If no flag is present, the entire $ARGUMENTS string is the idea.


Instructions

You are running the Discovery Workflow for: $ARGUMENTS

Follow the Routing table above to determine which phases to execute. Each phase is self-contained and independently readable.

--mode socratic 선택 시: /socratic-question [아이디어]를 먼저 실행하세요. 사고 검증 질문 세트가 완성되면 /harness-discover [아이디어]로 돌아오세요. (socratic-question을 직접 실행하지 않고 안내만 합니다.)


Interview Discipline (Phase 전반에 적용)

: 인터뷰는 가설을 확인하는 자리가 아니라 모르는 것을 발견하는 자리입니다. 질문이 많을수록, AI가 생성한 페르소나를 쓸수록 발견의 질이 낮아집니다.

모든 Phase에서 고객·사용자와 대화할 때 아래 4가지 규칙을 따른다:

규칙 1 — 질문 1개씩 복합 질문 금지.

  • ✅ "언제 마지막으로 이 문제를 겪었나요?"
  • ❌ "이 문제가 언제, 어디서, 왜 발생하나요?"

규칙 2 — Multiple choice 우선 열린 질문보다 선택지를 먼저 제시한다.

  • ✅ "A: 직접 해결 / B: 담당자에게 위임 / C: 그냥 넘어감 — 가장 가까운 것은?"
  • ❌ "이 상황에서 어떻게 하시나요?"

Read the full file on GitHub · 356 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 8d ago First seen · 356 lines · 51 tokens per session scan A c99ec47ed5dd

Subscribe to this mod's changes

harness-discover is a command published in the GitHub repository kimsanguine/hplan (2 stars, last pushed 23d ago), licensed MIT. It adds 51 tokens to every session and 4,061 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.