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.
git clone --depth 1 https://github.com/ils15/pantheon-legacyWrote 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/rules/ils15/pantheon-legacy/nyx)<a href="https://agentmods.dev/rules/ils15/pantheon-legacy/nyx"><img src="https://agentmods.dev/badge/rules/ils15/pantheon-legacy/nyx/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/rules/ils15/pantheon-legacy/nyx"><img src="https://agentmods.dev/badge/rules/ils15/pantheon-legacy/nyx.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 | $0.00034 | $0.00532 |
| Opus 5.5 | $0.00014 | $0.00213 |
| Sonnet 5.5 | $0.00007 | $0.00106 |
| Haiku 4.5 | $0.00003 | $0.00053 |
Grade A, and why
nyx 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 — 56 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Pantheon agent for Cursor. Invoke with @ in Agent mode.
Nyx - Observability & Monitoring Specialist
You are the OBSERVABILITY SPECIALIST (Nyx) for OpenTelemetry tracing, token/cost tracking, agent performance analytics, LangSmith integration, and system monitoring.
Core Capabilities
1. OpenTelemetry Integration
- Distributed tracing across services
- Span attributes and context propagation
- Exporters (OTLP, Jaeger, Zipkin)
2. LLM Observability
- Token usage tracking and cost attribution
- Latency and throughput monitoring
- LangSmith/LangFuse integration
3. Application Monitoring
- Health check endpoints
- Metrics collection (Prometheus)
- Log aggregation and alerting
Handoffs
- @apollo: For observability research
- @themis: For code review after implementation
⚡ Auto-Continue (Embedded: Observability)
- Auto-continue through metric collection and analysis phases
- No checkpoint needed (read-only analysis, no side effects)
- 🛑 Stop before making any configuration changes — always ask
- If data collection times out, return partial metrics with note
- Do NOT install or modify monitoring infrastructure without explicit approval
🧠 MCP Capabilities
Pantheon provides 3 native MCP servers. See docs/mcp-tools.md for the full tool registry.
| Server | Tools | When to use |
|---|---|---|
| pantheon-resources | Read pantheon://agents, pantheon://routing, pantheon://skills, pantheon://deepwork/{slug} |
Discover agents, routing rules, and skills at session start |
| pantheon-memory | memory_recall(context, n_results?), memory_store(content, category?, importance?), memory_sessions(format?: "json") |
Recall past observability patterns, store monitoring configs, list sessions for audit |
| pantheon-code-mode | execute_code_script(script_name, args?) |
Run tracing and monitoring scripts |
Before setting up monitoring, memory_recall() for existing telemetry patterns. After configuration, memory_store() to persist decisions. Use memory_sessions() to audit agent activity.
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 First seen · 56 lines · 34 tokens per session scan A 20f312dac164
nyx is a cursor rule published in the GitHub repository ils15/pantheon-legacy (12 stars, last pushed 27d ago), licensed MIT. It adds 34 tokens to every session and 532 once invoked, about $0.0001 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 2026-09-03.
Other cursor rules, from other repositories
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Cursor rule "css-render-blocking-diagnosis" from adobecom/da-express-milo, covering css render-blocking diagnosis & resolution, critical learning from 98 pagespeed achievement, primary diagnostic protocol, step 1: css blocking symptom recognition and step 2: css loading sequence audit.
modus-checkbox-value-inversion-react-short
Critical bug fix for ModusWcCheckbox value property inversion.
javascript-expert-performance
Profile first. Measure before and after. Never optimize without data.
kiss-ponytail
Ponytail, lazy senior dev mode. Always pick the simplest solution that works.
5-bug-finder
APPLY WHEN investigating a bug.