RepoBrain is a repository knowledge engine that lets coding agents ask grounded questions about a codebase and receive answers linked to source files and lines. It is for developers using Claude Code, Cursor, Codex, Windsurf, and other AI coding tools. Catalogue add-ons extend its commands, instructions, skills, rules, plugin, and hook workflows.
Borrowing it
Nothing to install: this file belongs to study8677/repobrain. 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/study8677/repobrain/main/.github/prompts/openspec-apply.prompt.mdgit clone --depth 1 https://github.com/study8677/repobrainWrote 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/commands/study8677/repobrain/openspec-apply)<a href="https://agentmods.dev/commands/study8677/repobrain/openspec-apply"><img src="https://agentmods.dev/badge/commands/study8677/repobrain/openspec-apply/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/commands/study8677/repobrain/openspec-apply"><img src="https://agentmods.dev/badge/commands/study8677/repobrain/openspec-apply.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 | $0.00012 | $0.00281 |
| Opus 5 | $0.00006 | $0.00140 |
| Sonnet 5 | $0.00002 | $0.00056 |
| Haiku 4.5 | $0.00001 | $0.00028 |
Grade A, and why
openspec-apply 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.
Copies of this mod
8 near-identical copies found in the catalogue:
- /openspec-apply — 89% identical, 5 lines differ
- /openspec-apply — 89% identical, 5 lines differ
- /openspec-apply — 89% identical, 5 lines differ
- /openspec-apply — 89% identical, 5 lines differ
- /openspec-apply — 89% identical, 5 lines differ
- /openspec-apply — 89% identical, 5 lines differ
- /openspec-apply — 89% identical, 5 lines differ
- /openspec-apply — 89% identical, 5 lines differ
What it actually says
$ARGUMENTS
Guardrails
- Favor straightforward, minimal implementations first and add complexity only when it is requested or clearly required.
- Keep changes tightly scoped to the requested outcome.
- Refer to
openspec/AGENTS.md(located inside theopenspec/directory—runls openspecoropenspec updateif you don't see it) if you need additional OpenSpec conventions or clarifications.
Steps Track these steps as TODOs and complete them one by one.
- Read
changes/<id>/proposal.md,design.md(if present), andtasks.mdto confirm scope and acceptance criteria. - Work through tasks sequentially, keeping edits minimal and focused on the requested change.
- Confirm completion before updating statuses—make sure every item in
tasks.mdis finished. - Update the checklist after all work is done so each task is marked
- [x]and reflects reality. - Reference
openspec listoropenspec show <item>when additional context is required.
Reference
- Use
openspec show <id> --json --deltas-onlyif you need additional context from the proposal while implementing.
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.
- yesterday First seen · 23 lines · 12 tokens per session scan A aab0b515597d
openspec-apply is a command published in the GitHub repository study8677/repobrain (1,323 stars, last pushed yesterday), licensed MIT. It adds 12 tokens to every session and 281 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 2026-09-08.
Other commands, from other repositories
arrange-workspace-flow-choose-workspace-layout
Phase 1 Choose Workspace Layout of arrange-workspace-flow.
arrange-workspace-flow
Workflow for arranging a workspace: layout, reference source code, business/technical context, ecosystem setup.
arrange-workspace-flow-configure-ecosystem
Phase 6 Configure Ecosystem of arrange-workspace-flow.
arrange-workspace-flow-business-context
Phase 3 Business context of arrange-workspace-flow.
modernization-flow-crossproject
Phase 5 Cross-Project Analysis of modernization-flow.
arrange-workspace-flow-modernization
Phase 5 Modernization of arrange-workspace-flow.