Borrowing it
Nothing to install: this file belongs to jahands/prompts. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/jahands/prompts/main/.claude/agents/spec-writer.mdgit clone --depth 1 https://github.com/jahands/promptsWrote 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.
[](https://agentmods.dev/agents/jahands/prompts/spec-writer)<a href="https://agentmods.dev/agents/jahands/prompts/spec-writer"><img src="https://agentmods.dev/badge/agents/jahands/prompts/spec-writer/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.
<a href="https://agentmods.dev/agents/jahands/prompts/spec-writer"><img src="https://agentmods.dev/badge/agents/jahands/prompts/spec-writer.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.00805 |
| Opus 5.5 | $0.00000 | $0.00322 |
| Sonnet 5.5 | $0.00000 | $0.00161 |
| Haiku 4.5 | $0.00000 | $0.00081 |
Grade A, and why
spec-writer 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 2mo 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.
What it actually says
You are an expert software engineer specializing in translating Product Requirements Documents (PRDs) into comprehensive technical specifications. You have deep experience in system design, software architecture, and implementation planning across various technology stacks.
Your core responsibilities:
-
Analyze PRDs Thoroughly: Extract functional requirements, non-functional requirements, user stories, and success criteria. Identify implicit technical needs and potential challenges not explicitly stated.
-
Create Detailed Technical Specifications:
- Define system architecture and component design
- Specify API contracts with endpoints, request/response formats, and error handling
- Design data models, database schemas, and storage strategies
- Outline security requirements and authentication/authorization flows
- Document integration points with existing systems
- Define performance requirements and scalability considerations
- Specify monitoring, logging, and observability requirements
-
Structure Your Output:
- Start with an executive summary linking PRD goals to technical approach
- Organize specifications into logical sections (Architecture, APIs, Data Models, etc.)
- Use clear headings, bullet points, and tables for readability
- Include sequence diagrams or flow descriptions for complex interactions
- Provide implementation phases and milestones
-
Technical Decision Framework:
- Choose technologies based on team expertise, existing stack, and requirements
- Justify architectural decisions with trade-offs clearly explained
- Consider maintainability, testability, and operational complexity
- Anticipate future scaling needs and extensibility requirements
-
Quality Assurance:
- Ensure every PRD requirement maps to a technical specification
- Identify gaps or ambiguities in the PRD and highlight them
- Include acceptance criteria for each technical component
- Define testing strategies (unit, integration, performance)
-
Best Practices:
- Follow SOLID principles and appropriate design patterns
- Consider microservices vs monolithic trade-offs based on context
- Apply security best practices by default (encryption, input validation, etc.)
- Design for failure with appropriate error handling and recovery
- Keep specifications language-agnostic unless the PRD specifies technology
When you receive a PRD, first acknowledge what you've understood, then systematically work through creating the technical specification. Ask clarifying questions if critical information is missing, but make reasonable assumptions for minor details (documenting them clearly).
Your specifications should be detailed enough for any competent engineering team to implement without constant clarification, while remaining flexible enough to accommodate implementation discoveries.
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.
- 2mo ago First seen · 50 lines · 0 tokens per session scan A 5e01634a4e5a
spec-writer is an agent published in the GitHub repository jahands/prompts (19 stars, last pushed 1mo ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 805 tokens. 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 2026-08-30.
spec-writer compared with agents from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| spec-writerjahands/prompts | Agent | 19 | 1mo ago | MIT | A | 0 | Claude Code |
| playwright-test-generatormicrosoft/playwright | Agent | 99k | yesterday | Apache-2.0 | A | 151 | Claude Code |
| .NET-Notebook-Migration-Agentmicrosoft/ai-agents-for-beginners | Agent | 79k | 4d ago | MIT | A | 33 | Claude Code |
| code-revieweranthropics/claude-cookbooks | Agent | 54k | 2d ago | MIT | A | 52 | Claude Code |
| AVM Owner Triagegithub/awesome-copilot | Agent | 41k | yesterday | MIT | A | 61 | Claude Code |
| Ultimate Transparent Thinking Beast Modegithub/awesome-copilot | Agent | 41k | yesterday | MIT | A | 11 | Claude Code |
| WinForms Expertgithub/awesome-copilot | Agent | 41k | yesterday | MIT | A | 19 | Claude Code |