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.
npx agentmods add rules/brighton-labs/railguard-cursor-coding/data-science-python-no-railguard-availablegit clone --depth 1 https://github.com/brighton-labs/railguard-cursor-codingWhat 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 | $0.01134 | $0.01134 |
| Opus 5 | $0.00567 | $0.00567 |
| Sonnet 5 | $0.00227 | $0.00227 |
| Haiku 4.5 | $0.00113 | $0.00113 |
Grade A, and why
data-science-python-no-railguard-available 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 3d 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.
R: Risk First
- The objective is to generate privacy-preserving, auditable data science code that treats all datasets as potentially untrusted.
- AI-generated workflows should prevent PII leakage, unsafe previews, over-permissive exports, or the use of risky dynamic evaluation functions.
- Output code must consider that notebooks may be shared publicly or reviewed externally.
A: Attached Constraints
- Do not use
eval(),exec(),pd.eval(), orpandas.query()with raw or user-controlled data. - Do not preview (
.head(),.sample()) or visualize data before dropping or masking PII. - Never export datasets (CSV, Excel) without reviewing and excluding sensitive fields.
- Avoid printing or logging raw values containing names, emails, phone numbers, IPs, or other PII.
- Do not embed secrets (API keys, tokens, credentials) in notebooks or data transformation code.
I: Interpretative Framing
- Treat CSV, Excel, JSON, or Parquet files as potentially malformed, misencoded, or manipulated.
- If a chart or
.head()preview is created, assume the data must be pre-sanitized. - All exports must be assumed auditable or shared — apply field-level filtering and file versioning.
- Markdown or notebook outputs must avoid embedding unescaped HTML or unfiltered user data.
L: Local Defaults
- Use
pandas.read_csv(..., dtype=...)andread_excel(..., engine="openpyxl", dtype=...)for structured, validated loads. - Define default sensitive columns:
PII_FIELDS = ["email", "full_name", "ssn", "ip", "dob", "phone", "address"] - Use
errors="ignore"when dropping columns withdf.drop(...). - Preview data only after dropping or masking sensitive fields.
- Use
with open(..., "r")for safe, explicit file access. - Use the
loggingmodule for observability, notprint().
G: Generative Path Checks
- Dataset Loading
- Apply column type enforcement and encoding
- Normalize column headers to lowercase + snake_case
- Validate expected columns, dimensions, and content assumptions
- Preprocessing
- Drop PII fields prior to calling
.head(),.to_csv(),.plot() - Apply clear inline comments to describe transformations
- Avoid implicit or silent
inplace=Truemodifications
- Drop PII fields prior to calling
- Exporting
- Confirm sensitive fields are excluded
- Add audit-friendly comments and logging entries
- Use versioned file naming (e.g.,
customers_clean_v1.csv)
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.
- 3d ago First seen · 109 lines · 1,134 tokens per session scan A bef950fc7e52
data-science-python-no-railguard-available is a cursor rule published in the GitHub repository brighton-labs/railguard-cursor-coding (13 stars, last pushed 1y ago), licensed MIT. It adds 1,134 tokens to every session, about $0.0057 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 2026-08-30.
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