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 skills add jggomez/expert-ai-developer-skills --skill cdc-scd-patternsgit clone --depth 1 https://github.com/jggomez/expert-ai-developer-skillsWrote 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/jggomez/expert-ai-developer-skills/cdc-scd-patterns)<a href="https://agentmods.dev/skills/jggomez/expert-ai-developer-skills/cdc-scd-patterns"><img src="https://agentmods.dev/badge/skills/jggomez/expert-ai-developer-skills/cdc-scd-patterns/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/skills/jggomez/expert-ai-developer-skills/cdc-scd-patterns"><img src="https://agentmods.dev/badge/skills/jggomez/expert-ai-developer-skills/cdc-scd-patterns.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 | $0.00060 | $0.01179 |
| Opus 5.5 | $0.00024 | $0.00472 |
| Sonnet 5.5 | $0.00012 | $0.00236 |
| Haiku 4.5 | $0.00006 | $0.00118 |
Grade A, and why
cdc-scd-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 today.
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 — 81 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CDC & SCD Patterns Skill
Overview
This skill guides the design and implementation of Change Data Capture (CDC) replication pipelines and Slowly Changing Dimension (SCD) modeling in Google Cloud BigQuery and Dataform. It acts as a Senior Data Engineer and Dimensional Modeling Specialist, ensuring accurate historical point-in-time tracking, idempotent MERGE statements, and clean transition from raw change logs to queryable dimension tables.
When to Use
Trigger Scenarios
- Replicating relational databases (Cloud SQL, AlloyDB, Oracle, Postgres) into BigQuery using Datastream.
- Designing dimensional models requiring historical auditability (SCD Type 1 vs. Type 2).
- Authoring Dataform
.sqlxmodels to deduplicate CDC event streams into current-state snapshots. - Generating automated SCD Type 2 merge SQL statements.
When NOT to Use
- High-level GCP cloud architecture and tool selection: Route to
gcp-data-engineering. - Query execution plan and indexing diagnostics: Route to
bigquery-query-optimization. - Application relational database migrations: Route to
database-migration-expert.
Process
Phase 1: Datastream CDC Ingestion & Bronze Landing
- Log-based CDC: Datastream streams inserts, updates, and deletes from the database transaction log into BigQuery bronze tables without impacting source database CPU.
- Bronze Table Metadata: Each record contains metadata columns (
_metadata_timestamp,_metadata_deleted,_metadata_change_type). - Serving Rule: Never expose the raw bronze change-log directly to reporting or BI tools. Materialize a silver table representing current state or an SCD Type 2 dimension.
Phase 2: Dimension Classification Matrix (SCD Types 0–6)
| Type | Behavior | Business Use Case |
|---|---|---|
| Type 0 | Retain original value permanently. | Original signup timestamp, initial creation dates. |
| Type 1 | Overwrite in place; no history preserved. | Typo corrections, attributes where history has zero analytical value. |
| Type 2 | New row per change with valid_from, valid_to, is_current. |
Default choice: Customer addresses, pricing tiers, account statuses. |
| Type 3 | Add previous_value column. |
Tracking only the immediately prior state alongside current. |
| Type 4 | Separate current table and historical log table. | Extremely high-churn dimensions where current queries must remain fast. |
| Type 6 | Hybrid: Type 2 versioning with a Type 1 current column. | Fast lookups without self-joins while retaining full historical auditability. |
What ships with it
2 files 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.
- today First seen · 81 lines · 60 tokens per session scan A edad86b02d83
cdc-scd-patterns is a skill published in the GitHub repository jggomez/expert-ai-developer-skills (30 stars, last pushed yesterday), licensed Apache-2.0. It adds 60 tokens to every session and 1,179 once invoked, about $0.0002 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 2026-11-06.
cdc-scd-patterns compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| cdc-scd-patternsjggomez/expert-ai-developer-skills | Skill | 30 | yesterday | Apache-2.0 | A | 60 | Claude Code, Codex |
| create-prprisma/orm | Skill | 48k | yesterday | Apache-2.0 | A | 48 | Claude Code, Codex |
| draft-release-notesprisma/orm | Skill | 48k | yesterday | Apache-2.0 | A | 174 | Claude Code, Codex |
| publish-npm-versionprisma/orm | Skill | 48k | yesterday | Apache-2.0 | A | 182 | Claude Code, Codex |
| triage-contributor-prprisma/orm | Skill | 48k | yesterday | Apache-2.0 | A | 131 | Claude Code |
| contrib-prprisma/orm | Skill | 48k | yesterday | Apache-2.0 | A | 65 | Claude Code, Codex |
| review-implement-phaseprisma/orm | Skill | 48k | yesterday | Apache-2.0 | A | 38 | Claude Code |