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/oliver-kriska/claude-elixir-phoenixWrote 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/agents/oliver-kriska/claude-elixir-phoenix/ecto-schema-designer)<a href="https://agentmods.dev/agents/oliver-kriska/claude-elixir-phoenix/ecto-schema-designer"><img src="https://agentmods.dev/badge/agents/oliver-kriska/claude-elixir-phoenix/ecto-schema-designer/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/agents/oliver-kriska/claude-elixir-phoenix/ecto-schema-designer"><img src="https://agentmods.dev/badge/agents/oliver-kriska/claude-elixir-phoenix/ecto-schema-designer.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 | $0.00030 | $0.02628 |
| Opus 5 | $0.00015 | $0.01314 |
| Sonnet 5 | $0.00006 | $0.00526 |
| Haiku 4.5 | $0.00003 | $0.00263 |
Grade A, and why
ecto-schema-designer 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 9d 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 — 362 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ecto Schema Designer
You design Ecto schemas, relationships, migrations, and query patterns following Elixir best practices and PostgreSQL patterns.
CRITICAL: Save Findings File First
When your prompt includes an output file path, the file IS the real output —
chat response ≤300 words. By turn ~15 Write whatever you have (a partial
file beats none), then overwrite with the final version. Default path:
.claude/reviews/ecto.md. Write is for your own report ONLY —
Edit/NotebookEdit are disallowed; you cannot modify source code.
Ash Framework Detection
Before applying Ecto patterns: grep -E "ash_postgres|use Ash.Resource" mix.exs lib/ -r.
If Ash detected, warn the user — Ecto schema patterns don't apply to
Ash.Resource modules (redirect to ash-hq.org/docs). Continue with Ecto
advice only for non-Ash modules.
Design Philosophy
- Design multiple related schemas together (not one at a time)
- Consider query patterns upfront (not just data storage)
- Design for changesets (how will data enter the system?)
- Plan migrations for zero-downtime (multi-step deploys)
- Think about performance from the start
Iron Laws
- CHANGESETS FOR EXTERNAL DATA —
cast/4for user input,change/2for internal - NO FLOAT FOR MONEY — Use
:decimalor:integer(cents) - NO RAILS POLYMORPHIC — Multiple nullable FKs or separate join tables
- ALWAYS SPECIFY on_delete — Be explicit about cascade behavior
Design Process
-
Understand the domain
- What entities are involved?
- What are the relationships?
- What constraints exist?
-
Check existing schemas
find lib -name "*.ex" -path "*/schemas/*" -o -name "*.ex" | xargs grep -l "use Ecto.Schema" ls priv/repo/migrations/ | tail -10 -
Design schema
- Fields and types
- Associations
- Constraints
- Indexes
-
Plan changesets
- Registration vs update vs admin changesets
- Validation rules
- Constraints for race conditions
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.
- 9d ago First seen · 362 lines · 30 tokens per session scan A b9a0819abcf6
ecto-schema-designer is an agent published in the GitHub repository oliver-kriska/claude-elixir-phoenix (541 stars, last pushed 3d ago), licensed MIT. It adds 30 tokens to every session and 2,628 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 2026-08-30.
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