Beating GPT5.5-xhigh for Coding agent security with SLMs and IRM
Details
- External ID
- 49472151
- Source
- HN
- Company
- —
- Product
- Beating GPT5.5-xhigh for Coding agent security with SLMs and IRM
- Website domain
- harden.run
- Launched
- Aug. 27, 2026
- Cohort
- —
- Upvotes
- 9
- Upvotes percentile
- 0.5309139784946236
- Tags
- —
- Fetched at
- Sept. 10, 2026, 5:31 a.m.
- Updated at
- Sept. 10, 2026, 5:31 a.m.
Description
Coding agents craft arbitrary code so securing them is more complicated than red-teaming. We post trained a cyber-security small llm, changed how it reasons and supplemented our controls using program analysis techniques such as inline reference monitoring to outperform GPT5.5-xhigh on hard benchmarks like LinuxArena and SleightBench.Free product available at harden.run and full benchmarks in the blog post.
Enrichment
- Theme
- developer tools for AI agents
- Vertical
- Security
- Function
- Agent / copilot
- Audience
- Developer
- AI stance
- AI-native
- Project type
- Commercial product
- Normalized one-liner
- secure coding agent using small language models
- Manually corrected
- False
Could you build this?
No Post-training specialized security small language models and integrating them with formal program analysis techniques like inline reference monitoring requires cutting-edge ML research and cybersecurity domain knowledge.
What it would actually take: Requires fine-tuning SLMs (like Llama or Mistral variants) using curated cybersecurity datasets and reinforcement learning/DPO, coupled with abstract syntax tree parsing and inline reference monitors (IRM) to enforce runtime security invariants on generated code. The stack involves PyTorch, vLLM or Triton for low-latency inference, and compiler instrumentation tools. Deep expertise in language model alignment, binary/source code static analysis, and offensive security is required.
Discussion
5 comments analyzed.
Concerns raised: Auditability and detectability of non-coding behaviors, Detecting coordinated attacks across multiple agents, Handling dynamically composed tool calls, Evidence exposure when calls are blocked or rewritten
Feature requests: Fine-tuned SLMs for security monitoring at scale, Visibility into agent behavior and actions, Cross-agent attack detection
Competitors
Other products that read as similar to this one — 300 launches clear the similarity bar, closest 8 shown.
Attention rank: #138 of 301 (itself plus its competitors, highest first — normalized so YC and Product Hunt are compared fairly).
Launched 301 days after the earliest competitor.
- Akon Labs: We're building the most token-efficient coding agent in the world · yc · 2026-08-17 · 45 upvotes · similarity 0.44
- Runtime - Let your whole team ship safely with coding agents · yc · 2026-04-13 · 29 upvotes · similarity 0.44
- RepoMethod · ph · 2026-09-13 · 2 upvotes · similarity 0.42
- Agent-pd · hn · 2026-06-09 · 6 upvotes · similarity 0.42
- Autofix Bot · hn · 2025-12-11 · 37 upvotes · similarity 0.42
- Recurse · hn · 2026-09-25 · 8 upvotes · similarity 0.42
- GPT‑5.4 mini and nano · ph · 2026-03-18 · 267 upvotes · similarity 0.41
- self-compact-pi-agent · github · 2026-09-20 · 54 upvotes · similarity 0.41
Other launches for this product
- No other launches for this product.
Same idea, different domain
Nobody's really built a agent / copilot tool for Agriculture yet.