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/ils15/pantheon-legacy/nyxgit 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.svg" alt="Measured on agentmods" 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 | $0.00034 | $0.00532 |
| Opus 5 | $0.00017 | $0.00266 |
| Sonnet 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 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.
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.
- yesterday First seen · 56 lines · 34 tokens per session scan A 20f312dac164
nyx is a cursor rule published in the GitHub repository ils15/pantheon-legacy (10 stars, last pushed yesterday), licensed MIT. It adds 34 tokens to every session and 532 once invoked, about $0.0002 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 2026-09-03.
Other cursor rules, from other repositories
angular-20
This rule provides comprehensive best practices and coding standards for Angular development, focusing on modern TypeScript, standalone components, signals, and performance optimizations.
dev-standard
Apache Superset development standards and guidelines for Cursor IDE.
cli-error-handling
CLI command error handling patterns.
prefer-direct-imports-over-module-mocks
Prefer extracting a testable core over vi.mock / vi.resetModules when unit tests need to reach production logic entangled with config, env, or singletons.
control-plane-descriptors
Control plane descriptor and instance implementation patterns.
family-instance-domain-actions
Family instance domain action implementation patterns.