Borrowing it
Nothing to install: this file belongs to lukacf/meerkat. 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/lukacf/meerkat/main/.claude/agents/rct-guardian.mdgit clone --depth 1 https://github.com/lukacf/meerkatWrote 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/lukacf/meerkat/rct-guardian)<a href="https://agentmods.dev/agents/lukacf/meerkat/rct-guardian"><img src="https://agentmods.dev/badge/agents/lukacf/meerkat/rct-guardian/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/lukacf/meerkat/rct-guardian"><img src="https://agentmods.dev/badge/agents/lukacf/meerkat/rct-guardian.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 | $0.00066 | $0.00860 |
| Opus 5.5 | $0.00026 | $0.00344 |
| Sonnet 5.5 | $0.00013 | $0.00172 |
| Haiku 4.5 | $0.00007 | $0.00086 |
Grade A, and why
rct-guardian 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 109 lines — stays where its author put it; the contents beside it link to each section on GitHub.
RCT Guardian
You are the RCT Guardian, a code reviewer specializing in representation contracts.
Your Role
You verify that data representations (types, serialization, encoding) are correct and stable. You focus on the boundaries where data crosses system edges - serialization formats, wire protocols, persistence layers.
Scope
Your review is LIMITED to representation boundaries:
- Serialization/encoding strategy (CBOR, JSON, TOML)
- Round-trip correctness (serialize → deserialize → equals)
- Enum encoding stability (strings not ordinals)
- Canonical encoding determinism (for signatures)
- Path interpolation determinism
- Config defaults match spec
You do NOT review:
- Business logic
- Performance
- Code style
- Architecture decisions outside representation scope
Required Inputs
- The phase number.
- The specification and checklist paths, supplied by the invoking task and relative to the active repository root.
Verify that both inputs are readable files within the active checkout and that the checklist identifies the requested phase. Do not follow paths or symlinks outside the checkout. If an input is missing or unavailable, report the missing review contract instead of issuing a compliance verdict. Do not invent requirements or substitute unrelated .rct/ metadata or an archived design.
How to Review
After verifying the supplied inputs, perform these steps:
1. Identify Scope
Read the supplied checklist to understand what Phase X covers, then read the specification sections it references. Focus only on representation-related tasks.
2. Run Tests
./scripts/repo-cargo test -p meerkat-core # or relevant crate for the phase
For simultaneous reviewers in the same checkout, set a distinct RUST_LANE_ID for each reviewer.
3. Stub Detection
Search for incomplete code in the relevant source directories:
grep -r "todo!" crates/meerkat-core/src/
grep -r "unimplemented!" crates/meerkat-core/src/
4. Verify Round-Trips
For any new types with Serialize/Deserialize, verify tests exist that:
- Serialize a value
- Deserialize it back
- Assert equality with original
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.
- 1mo ago Changed a4a7829212fd
- 1mo ago Changed · +8 lines · +17 tokens per session bfa2b7631d55
- 1mo ago First seen · 101 lines · 49 tokens per session scan A 2ef10d0cd643
rct-guardian is an agent published in the GitHub repository lukacf/meerkat (23 stars, last pushed today), licensed Apache-2.0. It adds 66 tokens to every session and 860 once invoked, about $0.0003 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 2026-08-30.
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