# Rails Llm Integration

> >

- **Type:** Skill
- **Install:** `agentstack add skill-nagstler-rails-llm-integration-rails-llm-integration`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [nagstler](https://agentstack.voostack.com/s/nagstler)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [nagstler](https://github.com/nagstler)
- **Source:** https://github.com/nagstler/rails-llm-integration

## Install

```sh
agentstack add skill-nagstler-rails-llm-integration-rails-llm-integration
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Rails LLM Integration Skill

## What This Skill Does

Teaches Claude to write LLM integrations the Rails Way -- treating LLM calls like
first-class Rails citizens alongside ActionMailer (email), ActiveJob (background work),
and ActionController (HTTP). Instead of scattered API calls, you get conventions.

## When to Use

- Adding any AI/LLM feature to a Rails application
- Using ruby_llm gem, langchain-rb gem, ruby-openai, or anthropic-rb in Rails
- Setting up prompt management, model routing, or cost tracking
- Building eval pipelines with Braintrust
- Building RAG pipelines with langchain-rb and pgvector
- Auditing existing LLM usage for anti-patterns
- Testing AI-powered features

## Architecture Overview

```
app/
  services/
    llm/
      base_service.rb          # All LLM calls inherit from this
      concerns/                # Traceable, Retryable, CostTrackable
      product_description_service.rb
      ticket_triage_service.rb
      errors.rb                # Typed error hierarchy
      result.rb                # Result monad
  jobs/
    llm/
      base_job.rb              # Async LLM calls inherit from this
      generate_description_job.rb
  prompts/                     # Prompts as views (ERB templates)
    product_descriptions/
      generate.text.erb
      generate.system.erb
    ticket_triage/
      classify.text.erb
config/
  llm.yml                     # Model config like database.yml
  initializers/
    llm.rb                    # Boot-time config validation
lib/
  llm/
    client.rb                 # Client factory: LLM::Client.for(model)
    clients/
      openai_client.rb        # Wraps ruby-openai gem
      anthropic_client.rb     # Wraps anthropic-rb gem
      ruby_llm_client.rb      # Wraps ruby_llm gem (multi-provider)
      langchain_client.rb     # Wraps langchain-rb gem
      proxy_client.rb         # LiteLLM/Portkey via Faraday
      stub_client.rb          # Test double
    config.rb                 # Loads config/llm.yml
    router.rb                 # Task-based model routing
    cost_tracker.rb           # Redis-backed cost tracking
    prompt_renderer.rb        # ERB-based prompt rendering
db/
  migrate/
    create_llm_batches.rb     # Batch job tracking
    create_llm_dead_letters.rb # Permanent failure tracking
    create_llm_eval_cases.rb  # Eval dataset storage
    create_llm_experiment_logs.rb # Shadow experiment results
```

## Installation

```bash
rails generate llm:install       # Sets up everything above
rails generate llm:service ProductDescription generation  # Scaffold a new service
```

## Reference Files

| File | Read When You Need To... |
|------|--------------------------|
| `references/client-setup.md` | Wire up ruby_llm, langchain-rb, ruby-openai, anthropic-rb, or proxy clients (start here) |
| `references/service-patterns.md` | Build LLM service objects with Result, tracing, retries |
| `references/job-patterns.md` | Make LLM calls async with ActiveJob + Sidekiq |
| `references/proxy-routing.md` | Route between models, optimize costs, set budgets |
| `references/eval-pipeline.md` | Set up Braintrust evals and quality scoring |
| `references/prompt-management.md` | Manage prompts as ERB templates (prompts-as-views) |
| `references/testing-guide.md` | Test LLM features with stubs, VCR, and CI strategy |
| `references/generators.md` | Rails generators for `llm:install` and `llm:service` |
| `templates/migrations/` | Database schemas for batches, dead letters, eval cases |
| `scripts/audit_llm_usage.rb` | Scan a Rails app for LLM anti-patterns |

## Core Principles

1. **Rails conventions wrap LLM libraries** -- ruby_llm and langchain-rb are the engine,
   Rails patterns are the chassis. Use service objects, ActiveJob, ERB templates, and
   YAML config. The gem handles the API; the convention handles everything else.

2. **Async by default** -- Every LLM call goes through ActiveJob unless the user is
   actively waiting (streaming). Never block a web request on a 3-second API call.

3. **Cost-aware routing** -- Every call has an estimated cost. Route cheap tasks to
   cheap models. Set daily budgets. Alert before you hit them.

4. **Eval-first development** -- Log every call with Braintrust. Build eval datasets
   from production traces. Score quality automatically. Gate deployments on eval
   regressions.

5. **Prompts are views** -- Prompts live in `app/prompts/` as ERB templates, versioned
   in git, rendered with locals, tested independently from API calls.

6. **Errors are typed** -- RateLimitError, TimeoutError, ContentFilterError,
   BudgetExceededError. Each has its own retry and alerting strategy.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [nagstler](https://github.com/nagstler)
- **Source:** [nagstler/rails-llm-integration](https://github.com/nagstler/rails-llm-integration)
- **License:** MIT

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-nagstler-rails-llm-integration-rails-llm-integration
- Seller: https://agentstack.voostack.com/s/nagstler
- Browse the marketplace: https://agentstack.voostack.com/browse

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