AI Submissions for Fri Dec 26 2025
Building an AI agent inside a 7-year-old Rails monolith
Submission URL | 104 points | by cionescu1 | 53 comments
Building an AI agent inside a 7-year-old Rails monolith with strict data boundaries
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Context: Mon Ami runs a 7-year-old, multi-tenant Rails monolith for aging/disability case workers, with heavy Pundit-based authorization and Algolia for client search due to DB performance limits. The team assumed AI wasn’t a safe or practical fit given sensitive data and complex access rules.
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Spark: After a RubyLLM talk at SF Ruby, the author realized they could safely expose data to an LLM by funneling all retrieval through “tools” that encode authorization logic—letting the model orchestrate, not access, data.
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Approach:
- Use the ruby_llm gem to abstract LLM providers and manage a Conversation thread with tool/function calling.
- Implement a SearchTool that:
- Queries Algolia for client candidates.
- Applies Pundit policy scope to filter to only what the current user can see.
- Returns a small, whitelisted payload (e.g., id, slug, name, email) to the model.
- The LLM never touches the DB or unrestricted records—only tool outputs that already passed auth.
- Lightweight Rails UI: Turbo Streams for live updates, a background job (ProcessMessageJob) to call conversation.ask, and a Stimulus controller for auto-scroll.
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Why it works: This is a thin, RAG-like pattern without a vector DB—using existing Algolia infra and strict, code-enforced access controls inside tools. It turns the LLM into a safe “glue layer” between natural-language queries and authorized data retrieval.
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Takeaways:
- Even policy-heavy, multi-tenant apps can ship practical AI by enforcing access at the tool boundary.
- Start with narrow, high-signal tools (e.g., client lookup) and small whitelisted responses.
- Model choice can be flexible; if tools do the heavy lifting, smaller/faster models often suffice, with larger-context models reserved for longer chats.
A neat case study in adding AI to a legacy Rails app without compromising data boundaries—using tools as guardrails rather than granting the model free rein.
The discussion centers on the architectural trade-offs of the presented approach, specifically comparing Ruby AI libraries and debating the privacy implications of the "tool-use" pattern.
Library Comparison: ruby_llm vs. DSPy.rb
The creator of DSPy.rb provided a detailed comparison between their library and the ruby_llm gem used in the article. They noted that while ruby_llm offers a clean low-level API for managing tool definitions and conversation history, it requires manual prompt engineering. In contrast, DSPy.rb abstracts prompts into typed signatures and modules, which is purportedly better suited for complex systems involving ephemeral memory or multiple specialized models. It was suggested that while the article's single-tool approach works well for simple cases, larger contexts might eventually struggle with token limits, necessitating a framework that decomposes tasks.
Privacy and Data Flow Commenters drilled down into the definition of "safe" usage in this context. While the author claimed strict boundaries, users clarified that the LLM does still receive the private data (e.g., client names/emails) in order to format the final answer. The security relies on the application code filtering the retrieval before sending it to the LLM, rather than the LLM querying the DB directly. Participants agreed the risk profile is effectively "trusting a 3rd party vendor via legal agreements" (comparable to hosting data on AWS), rather than true data isolation.
Other Takeaways:
- Hype Fatigue: There was some pushback against the prevalence of AI topics in the Ruby community, with concerns raised regarding the environmental impact of generative AI and skepticism about whether this is just a rehash of failed "Natural Language to SQL" attempts from the 2010s.
- Monolith Love: Users expressed appreciation for the article's defense of well-designed monolithic architectures over microservices, noting the ease of developing complex features like this when the entire context is available in one codebase.
Grok and the Naked King: The Ultimate Argument Against AI Alignment
Submission URL | 103 points | by ibrahimcesar | 61 comments
HN top story: “Grok proves alignment is about power, not principles”
Summary: An opinion piece argues that Elon Musk’s hands‑on tweaking of xAI’s Grok exposes AI “alignment” as a governance problem, not a technical one. When Grok’s answers clashed with Musk’s preferences, the post says they were promptly “corrected” via prompt and policy changes—illustrated by shifts like calling misinformation the biggest threat one day and low fertility the next, and a short‑lived “be politically incorrect” directive that led to offensive outputs before being rolled back. The author critiques RLHF and Constitutional AI as elegant but naive: because companies write and revise the “constitution,” alignment ultimately reflects whoever owns the weights. The takeaway: market forces and regulation—not alignment research—are the real checks on model behavior.
Why it matters:
- Highlights the concentration of power in deployed, closed models: owners can rapidly reshape “values.”
- Reframes alignment as a political and product‑governance issue rather than purely technical.
- Raises calls for transparency/auditability and clearer regulatory guardrails.
- Fuels debate over whether open weights, community governance, or standards bodies can counterbalance owner control.
Note: The piece relies on reported prompt changes and deleted posts; some claims may be disputed.
Based on the discussion, here is a summary of the comments:
The Definition and Impossibility of "Alignment"
- Several users argued that "AI alignment" is a flawed concept because humans are not aligned with one another. Since humanity has no single set of agreed-upon values, an AI cannot be aligned with "humanity"—only with specific subsets or individuals.
- Commenters noted that the "value" problem isn't new; it is simply a scaling of the human condition where different cultures and individuals have conflicting goals.
Musk vs. Other Labs (The "Double Standard" Debate)
- A significant portion of the thread debated whether Elon Musk’s manual tuning of Grok is different from what OpenAI or Google do.
- One camp argued that all AI companies engage in "value-shaping," but obscure it behind corporate bureaucracy and "safety" committees. They view Musk’s actions as merely exposing the reality that owners dictate the model's worldview.
- Another camp countered that there is a distinction between "safety" guardrails (trying to prevent hate speech) that accidentally misfire (e.g., Google Gemini’s historical inaccuracy scandal) and Musk’s deliberate tuning for a specific political ideology.
Immediate Risks vs. Existential Risks
- There was pushback against the focus on sci-fi "superintelligence" scenarios. Users argued that the real, immediate AI safety risk is bureaucratic and authoritarian—such as police officers trusting faulty facial recognition software 100% to make arrests.
- Others maintained that while immediate risks exist, the potential for AI to surpass human intelligence (comparing human-animal IQ gaps) remains a valid existential concern that shouldn't be dismissed just because humans are currently unaligned.
The Scale of Influence
- Users highlighted that the danger lies in leverage. A biased school teacher influences a classroom; a biased AI model owned by a single billionaire influences millions of users instantly.
- The discussion touched on the idea that current "safety" frameworks largely reflect modern Western internet culture (often described as inconsistent or ideologically specific), which alienates users who do not share those specific cultural norms.
TurboDiffusion: 100–200× Acceleration for Video Diffusion Models
Submission URL | 243 points | by meander_water | 46 comments
TurboDiffusion: 100–200× faster video diffusion on a single GPU
THU-ML released TurboDiffusion, an acceleration framework that claims 100–200× speedups for video diffusion models while maintaining quality. On an RTX 5090, end-to-end generation drops from 184s to 1.9s for a ~5-second clip (default 81 frames), enabled by:
- SageAttention/SLA (Sparse-Linear Attention) to speed up attention
- rCM for timestep distillation, cutting sampling to 1–4 steps
- Optional linear-layer quantization for consumer GPUs
What’s included
- Open source (Apache-2.0), with checkpoints for Wan 2.x models:
- TurboWan2.1 T2V (1.3B, 14B) at 480p/720p
- TurboWan2.2 I2V (A14B) at 720p
- Supports 480p and 720p; “best” quality varies by checkpoint
- Quantized checkpoints recommended for RTX 4090/5090; unquantized for >40GB VRAM (e.g., H100)
- PyTorch >=2.7.0 (2.8.0 recommended); higher versions may OOM
- Optional SageSLA path via SpargeAttn for maximum speed
Notes and caveats
- Paper and checkpoints are marked as not finalized and may change
- You must download VAE and umT5 encoder separately
- SLA/SageSLA quality-speed trade-offs (e.g., top-k ~0.15), and rCM sigma settings affect diversity/quality
Why it matters Near–real-time T2V/I2V on a single consumer GPU could unlock interactive video generation and edge deployment, and the techniques (sparse attention + step distillation + quantization) may generalize beyond Wan models.
Links
- Code: https://github.com/thu-ml/TurboDiffusion
- Paper (preprint): https://arxiv.org/pdf/2512.16093
- Checkpoints: linked from the GitHub README via Hugging Face
Discussion Summary:
The release of TurboDiffusion sparked a debate on the definition of "real-time" graphics, the practical utility of current video models, and the future of user interfaces.
- Rendering vs. "Hallucination": A significant portion of the discussion focused on distinguishing this technology from video games, which have achieved real-time rendering for decades. Commenters noted the fundamental difference in approach: games utilize explicit physics, logic, and polygon pipelines, whereas diffusion models rely on "imagination" or probabilistic image synthesis. Proponents view this as the "Pong" era of neural rendering, predicting a future convergence where "Holodeck"-style simulations merge physics engines with generative vision.
- Quality vs. Speed: While users were impressed by the speed (creating 5-second clips in ~2 seconds on a 5090), practical limitations were highlighted. One professional user noted that acceleration techniques often degrade fine details essential for production, such as lip-sync and character consistency. After testing TurboDiffusion for creating long-form educational content, they found that while generation was fast, the "usable" yield dropped significantly compared to slower methods.
- Dynamic User Interfaces: The prospect of running video models locally at 60FPS led to speculation about future UIs. Some visionaries argued this could end static design, allowing operating systems to generate bespoke interfaces on the fly based on user intent. Skeptics countered that standard patterns (like "buttons on the left") exist for usability reasons, regardless of generation capabilities.
- Risks and "Digital Heroin": The conversation touched on the psychological impact of hyper-personalized, real-time video generation. Users cited recent research on "digital heroin," raising concerns that infinite, tailored content loops could be addictive. This triggered a debate on safety guidelines versus censorship, with many arguing that strict restrictions are futile against open-weight models that can be run locally.
Show HN: Domain Search MCP – AI-powered domain availability checker
Submission URL | 5 points | by dorukardahan | 3 comments
Domain Search MCP: an open-source MCP server that lets AI assistants check domain availability, compare registrar pricing, and suggest alternatives
What it is
- A Model Context Protocol (MCP) server (TypeScript, MIT) designed for AI assistants—especially Claude Desktop—to handle domain searches, pricing, and suggestions without leaving chat.
Why it’s interesting
- Packages a common dev task (domain hunting) into a single tool with smart fallbacks: fast if you have registrar APIs, still works without keys via RDAP/WHOIS.
- Adds practical extras you usually end up scripting yourself: pricing comparisons, AI-powered name suggestions, and social handle checks.
How it works
- Sources: Porkbun API, Namecheap API (requires API key + IP whitelist), GoDaddy public endpoint, and RDAP/WHOIS fallbacks.
- Handles rate limits with exponential backoff and source fallback; structured error codes (INVALID_DOMAIN, RATE_LIMIT, TIMEOUT, NO_SOURCE_AVAILABLE).
- No keys needed to start; keys improve speed and pricing accuracy (Porkbun noted as 1000+ req/min).
Tools exposed
- search_domain: Check availability and pricing across TLDs.
- bulk_search: Up to 100 domains at once.
- compare_registrars: Find best price and recommendation.
- suggest_domains: Variants (prefix/suffix/hyphen) when taken.
- suggest_domains_smart: AI suggestions from keywords/descriptions.
- tld_info: TLD details, restrictions, typical pricing.
- check_socials: Username availability (e.g., GitHub, Twitter/X, Instagram).
Getting started
- Clone, npm install, build; add to Claude Desktop’s claude_desktop_config.json; then ask Claude to check a domain.
Good to know
- RDAP/WHOIS can be slow and rate-limited; API-backed checks are faster and more reliable.
- Pricing accuracy depends on registrar APIs; Namecheap needs IP whitelist.
- Latest release v1.1.0 mentions performance and security improvements.
- Repo: dorukardahan/domain-search-mcp (TypeScript-heavy, MIT).
Here is the digest for the Domain Search MCP submission and discussion:
The Scoop Domain Search MCP is an open-source server built for the Model Context Protocol that allows AI assistants (specifically Claude Desktop) to perform domain operations directly within the chat interface. Instead of switching tabs to check availability or pricing, developers can ask their AI to check domains, compare registrar prices (via Porkbun, Namecheap, and others), and generate available alternatives. It features smart fallbacks (using RDAP/WHOIS if API keys aren't present) and includes tools for checking social media handle availability.
The Discussion
- Context Switching: Creator drkrdhn explained that the project was born out of frustration with constant context-switching; they wanted to brainstorm project names with AI and get instant "is this available?" validation without jumping to a registrar site.
- Technical Robustness: The author highlighted the project's reliability, noting it includes Zod validation, LRU caching, rate limiting, and a suite of 98 tests.
- The "Premium" Problem: User r0fl expressed hesitation based on past experiences with similar tools, noting that automated searches often flag a domain as "available" only for the user to discover later that it is an expensive premium domain ($500+), and asked how this tool mitigates that issue.