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 skills/rudycity/superagent/projection-patternsnpx skills add RudyCity/superagent --skill projection-patternsgit clone --depth 1 https://github.com/RudyCity/superagentWrote 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/skills/rudycity/superagent/projection-patterns)<a href="https://agentmods.dev/skills/rudycity/superagent/projection-patterns"><img src="https://agentmods.dev/badge/skills/rudycity/superagent/projection-patterns.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 5.1 | $0.00036 | $0.00542 |
| Opus 5 | $0.00018 | $0.00271 |
| Sonnet 5 | $0.00007 | $0.00108 |
| Haiku 4.5 | $0.00004 | $0.00054 |
Grade A, and why
projection-patterns 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 2d 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.
This is a copy
100% identical to projection-patterns — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 63 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Projection Patterns
Comprehensive guide to building projections and read models for event-sourced systems.
When to Use This Skill
- Building CQRS read models
- Creating materialized views from events
- Optimizing query performance
- Implementing real-time dashboards
- Building search indexes from events
- Aggregating data across streams
Core Concepts
1. Projection Architecture
┌─────────────┐ ┌─────────────┐ ┌─────────────┐
│ Event Store │────►│ Projector │────►│ Read Model │
│ │ │ │ │ (Database) │
│ ┌─────────┐ │ │ ┌─────────┐ │ │ ┌─────────┐ │
│ │ Events │ │ │ │ Handler │ │ │ │ Tables │ │
│ └─────────┘ │ │ │ Logic │ │ │ │ Views │ │
│ │ │ └─────────┘ │ │ │ Cache │ │
└─────────────┘ └─────────────┘ └─────────────┘
2. Projection Types
| Type | Description | Use Case |
|---|---|---|
| Live | Real-time from subscription | Current state queries |
| Catchup | Process historical events | Rebuilding read models |
| Persistent | Stores checkpoint | Resume after restart |
| Inline | Same transaction as write | Strong consistency |
Templates and detailed worked examples
Full template library and detailed worked examples live in references/details.md. Read that file when you need the concrete templates.
Best Practices
Do's
- Make projections idempotent - Safe to replay
- Use transactions - For multi-table updates
- Store checkpoints - Resume after failures
- Monitor lag - Alert on projection delays
- Plan for rebuilds - Design for reconstruction
Don'ts
- Don't couple projections - Each is independent
- Don't skip error handling - Log and alert on failures
- Don't ignore ordering - Events must be processed in order
- Don't over-normalize - Denormalize for query patterns
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 2d ago First seen · 63 lines · 36 tokens per session scan A b05b06b24ea2
projection-patterns is a skill published in the GitHub repository RudyCity/superagent (20 stars, last pushed yesterday), licensed MIT. It adds 36 tokens to every session and 542 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to projection-patterns, differing in 0 lines, and is treated as a copy.
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