hdd

hdd is a command for Claude Code from Kastalien-Research/thoughtbox. It costs 17 tokens per session (437 once invoked), scanned A, original, MIT.

A deprecated command for running Hypothesis-Driven Development, a workflow that tests proposed solutions against evidence in several stages. Its replacement is an hdd skill.

In plain words
What is it for?
Use the replacement skill to coordinate research, create or review an architecture decision record, implement a change, validate it, and record whether the hypothesis was accepted.
Why use it?
It provides a structured path for research, design decisions, implementation, validation, and final decisions, while pointing users to the current entry point.

Command for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add commands/kastalien-research/thoughtbox/hdd
Clone the repo
git clone --depth 1 https://github.com/Kastalien-Research/thoughtbox

Made for: Claude Code.

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 hdd

README.md
[![agentmods](https://agentmods.dev/badge/commands/kastalien-research/thoughtbox/hdd.svg)](https://agentmods.dev/commands/kastalien-research/thoughtbox/hdd)
Your own site
<a href="https://agentmods.dev/commands/kastalien-research/thoughtbox/hdd"><img src="https://agentmods.dev/badge/commands/kastalien-research/thoughtbox/hdd.svg" alt="Measured on agentmods" height="20"></a>
Per session 17 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 437 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00017 $0.00437
Opus 5 $0.00009 $0.00218
Sonnet 5 $0.00003 $0.00087
Haiku 4.5 $0.00002 $0.00044

Measured yesterday against content hash fc7693dda6c9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

hdd 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 yesterday.

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.

apps/web/.claude/commands/hdd/hdd.md · 67 lines

What it actually says

/hdd (DEPRECATED)

This command is deprecated. Use the /hdd skill at .claude/skills/hdd/SKILL.md instead. The skill is the canonical HDD entry point with full sub-agent delegation templates, spec creation, reconciliation dispositions, and --phases support for /workflow integration.

The module briefs in ./modules/ remain as reference material for sub-agent context.


Original description (preserved for reference)

Run Hypothesis-Driven Development using small delegated modules.

Usage

/hdd <adr-number> "<title>" [--resume]

Instruction Budget

  • This orchestrator is router-only and must stay under the orchestrator budget policy.
  • Execution details live in phase modules.

Inputs

  • adr_number (required)
  • title (required)
  • resume (optional)

Delegation

  1. Research -> ./modules/research-brief.md
  2. Stage ADR -> ./modules/stage-adr-brief.md
  3. Implement -> ./modules/implement-brief.md
  4. Validate -> ./modules/validate-brief.md
  5. Decide -> ./modules/decide-brief.md

Orchestrator Steps

  1. Initialize or resume state.
  2. Delegate current phase using the standard handoff schema.
  3. Collect module output and persist phase result.
  4. Run user checkpoint after each phase.
  5. Append delegation trace event.
  6. Route to next phase until complete.

Checkpoints

  • After research: approve hypotheses.
  • After stage ADR: approve implementation scope.
  • After validate: confirm manual verification findings.
  • Before decision: confirm accept/reject action.

Output

  • Accepted ADR migrated to production path, or rejected ADR archived with rationale.
  • Workflow summary with outcomes and open risks.
  • Trace artifact at .claude/command-traces/hdd.jsonl.
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. yesterday First seen · 67 lines · 17 tokens per session scan A fc7693dda6c9

Subscribe to this mod's changes

hdd is a command published in the GitHub repository Kastalien-Research/thoughtbox (64 stars, last pushed 1mo ago), licensed MIT. It adds 17 tokens to every session and 437 once invoked, about $0.0001 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 2026-09-03.