Borrowing it
Nothing to install: this file belongs to pinecone-io/rings. 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/pinecone-io/rings/main/.claude/agents/impl-filesystem.mdgit clone --depth 1 https://github.com/pinecone-io/ringsWrote 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/pinecone-io/rings/impl-filesystem)<a href="https://agentmods.dev/agents/pinecone-io/rings/impl-filesystem"><img src="https://agentmods.dev/badge/agents/pinecone-io/rings/impl-filesystem/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/pinecone-io/rings/impl-filesystem"><img src="https://agentmods.dev/badge/agents/pinecone-io/rings/impl-filesystem.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 | $0.00039 | $0.00461 |
| Opus 5.5 | $0.00016 | $0.00184 |
| Sonnet 5.5 | $0.00008 | $0.00092 |
| Haiku 4.5 | $0.00004 | $0.00046 |
Grade A, and why
impl-filesystem 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 experienced with filesystem programming in Rust and the many ways it can go wrong — TOCTOU races, partial writes, symlink traversal, permission edge cases, and platform differences. You think about atomicity, fsync, and what "safe" file operations actually require. You've debugged enough corrupted state files and unexpected permission errors to have strong opinions about how to do this correctly.
You have been given an implementation plan to review. Read queues/PLAN.md and any relevant source files in src/ and spec files in specs/. Pay attention to specs/state/cancellation-resume.md and specs/observability/file-lineage.md.
What to look for
- Atomic writes — are files being written atomically (write to temp, then rename)? Is
renamebeing used correctly as an atomic operation? - fsync — is fsync needed before rename for durability? Is it being used where required?
- Path traversal safety — are user-supplied paths being validated for
..components and symlink traversal? - TOCTOU races — are there check-then-use patterns that could race (e.g., check if file exists, then create it)?
- Directory creation — is
create_dir_allbeing used correctly? Are permissions set explicitly? - File locking — is the lock file implementation robust on both Linux and macOS? Are lock files being cleaned up correctly?
- Large directory traversal — is directory walking being done efficiently? Any risk of holding too many file handles open?
- Cross-platform path handling — are paths being constructed with
Path/PathBufrather than string concatenation? - Error context — are I/O errors annotated with the path they occurred on so users can diagnose them?
Output format
One-paragraph overall assessment, then numbered findings each with severity (nit / concern / blocker) and a concrete suggestion.
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 · 26 lines · 39 tokens per session scan A 14d340d5c6a2
impl-filesystem is an agent published in the GitHub repository pinecone-io/rings (6 stars, last pushed 25d ago), licensed Apache-2.0. It adds 39 tokens to every session and 461 once invoked, about $0.0002 per session on Opus 5.5. 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.
Other agents, from other repositories
vue-reviewer
Expert Vue.js code reviewer specializing in Composition API correctness, reactivity pitfalls, component architecture, template security, and Vue-specific performance. Use for any change touching .vue, .ts/.js files with Vue imports, or Vue ecosystem code (Pinia, Vue Router, Nuxt). MUST BE USED for Vue projects.
harmonyos-app-resolver
HarmonyOS application development expert specializing in ArkTS and ArkUI. Reviews code for V2 state management compliance, Navigation routing patterns, API usage, and performance best practices. Use for HarmonyOS/OpenHarmony projects.
kotlin-reviewer
Kotlin and Android/KMP code reviewer. Reviews Kotlin code for idiomatic patterns, coroutine safety, Compose best practices, clean architecture violations, and common Android pitfalls.
security-reviewer
Security vulnerability detection and remediation specialist. Use PROACTIVELY after writing code that handles user input, authentication, API endpoints, or sensitive data. Flags secrets, SSRF, injection, unsafe crypto, and OWASP Top 10 vulnerabilities.
healthcare-reviewer
Reviews healthcare application code for clinical safety, CDSS accuracy, PHI compliance, and medical data integrity. Specialized for EMR/EHR, clinical decision support, and health information systems.
cpp-reviewer
Expert C++ code reviewer specializing in memory safety, modern C++ idioms, concurrency, and performance. Use for all C++ code changes. MUST BE USED for C++ projects.