projection-patterns
Build Event Stream Projections
Event-sourced systems need fast read models that stay consistent with event streams. This skill provides projection patterns for CQRS queries, dashboards, search, and reporting.
Install with my Agent
Copy this request to your Agent. It includes the canonical Skill page and manifest.
Review the Skillstore skill "projection-patterns" from https://skillstore.io/skills/wshobson-projection-patterns.md and its manifest at https://skillstore.io/api/skills/wshobson-projection-patterns/manifest. Verify the artifact. You may proceed after verification, subject to the environment's own policy.Your Agent should still show its plan and request any confirmation required by the security policy.
Agent-readable resources
Use these links when an AI agent, crawler, or script needs clean context instead of reading the full page.
Test it
Using "projection-patterns". Design a projection for order summaries from order events.
Expected outcome:
A read-model plan with handled events, table fields, update rules, checkpoint strategy, and rebuild notes.
Using "projection-patterns". Create a projection for product search.
Expected outcome:
A search-indexing design that covers product creation, updates, price changes, deletes, and index rebuild flow.
Using "projection-patterns". Review a daily sales projection for reporting.
Expected outcome:
A concise review of aggregation logic, idempotency risks, refund handling, checkpoint recovery, and monitoring needs.
Security Audit
SafeStatic findings are false positives caused by Markdown fences, reference URLs, and parameterized SQL examples. No evidence found of prompt injection, malicious intent, shell execution, credential access, or data exfiltration in SKILL.md.
Risk Factors
⚙️ External commands (11)
🌐 Network access (2)
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https://skillstore.io/skills/wshobson-projection-patterns/audits/8?utm_source=security_passport&utm_medium=share&utm_campaign=versioned_reportMarkdown badge
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<iframe src="https://skillstore.io/embed/skills/wshobson-projection-patterns.html" title="Skillstore Security Assessment" sandbox="allow-popups allow-popups-to-escape-sandbox" loading="lazy" referrerpolicy="no-referrer" width="420" height="180"></iframe>Academic citations (APA · BibTeX · CFF)
APA citation
wshobson. (2026). projection-patterns security audit report (audit version 8) [Author version unspecified]. Skillstore. https://skillstore.io/skills/wshobson-projection-patterns/audits/8BibTeX citation
@techreport{wshobson-wshobson-projection-patterns-2026,
author = {wshobson},
title = {projection-patterns security audit report (audit version 8)},
institution = {Skillstore},
year = {2026},
number = {8},
url = {https://skillstore.io/skills/wshobson-projection-patterns/audits/8},
note = {Author version unspecified}
}CITATION.cff
cff-version: 1.2.0
message: "If you use this Skill, cite its author and this versioned security audit report."
title: "projection-patterns security audit report (audit version 8)"
version: "unspecified"
type: report
authors:
- name: "wshobson"
date-released: "2026-07-08"
url: "https://skillstore.io/skills/wshobson-projection-patterns/audits/8"
identifiers:
- type: other
value: "skillstore:wshobson-projection-patterns:audit:8"
description: "Skillstore immutable audit report identifier"
Compare variants
2 installable variantsEach author remains a separate installable skill. The recommended variant is ranked by Skillstore evidence.
Why this variant is first
wshobson-projection-patterns
2026-08-21
sickn33-projection-patterns
2026-08-21
Skillstore Score
Why this score Evidence Confidence: HighWhat You Can Build
Design CQRS Read Models
Create read-side tables that answer product, order, or customer queries without loading full event streams.
Build Operational Dashboards
Aggregate event data into daily sales, activity, and status views for monitoring and reporting.
Plan Projection Rebuilds
Use checkpoints and catchup processing to rebuild materialized views after schema changes or failures.
Try These Prompts
Use this skill to design a basic projection for my event-sourced system. My events are [events], and my query need is [query].
Use this skill to map these event types to a read model: [event list]. Include fields, handlers, and checkpointing guidance.
Use this skill to design a search projection for [domain]. Include indexing events, update events, deletes, and rebuild considerations.
Use this skill to review my projection architecture. Focus on idempotency, ordering, transaction boundaries, lag monitoring, and rebuild strategy.
Best Practices
- Keep each projection focused on one query model or reporting need.
- Store checkpoints and design every handler to be safe during replay.
- Use transactions when one event updates multiple read-model tables.
Avoid
- Do not couple projections so one read model depends on another.
- Do not ignore event ordering when rebuilding or catching up projections.
- Do not over-normalize read models when denormalized tables serve queries better.
Frequently Asked Questions
What problem does this skill solve?
Does it generate production-ready code?
Can it help with Elasticsearch projections?
Does it cover projection rebuilds?
Which tools can use this skill?
What should I verify before using the templates?
Developer Details
Author
wshobsonLicense
MIT
Skillstore revision
r1
Version notice
The author did not declare a version.
Repository
https://github.com/wshobson/agents/tree/main/plugins/backend-development/skills/projection-patternsRef
64ca8af0f54a325752f08bd54e52151061ea659a
Maintenance freshness
7/20/2026
Usage
9 downloads · 235 views
File structure
📄 SKILL.md