Inspiration
Today's coding assistants operate like simple autocomplete: you request a feature or a bug fix, they spit out raw code, and you are left to copy-paste it, set up tests, interpret cryptic compiler errors, and manually debug what went wrong. Furthermore, single-model systems face a fundamental dilemma: either route everything through a massive flagship model (blowing your token budget and inducing high latency) or rely on a small model (which hallucinates complex system architectures).
With the availability of NVIDIA Nemotron open models on Nebius Token Factory, we asked: What if we could build a sovereign, high-throughput AI engineer that deconstructs problems across specialized cognitive tiers, verifies active API contracts using real-time search, executes automated tests in an isolated sandbox, and autonomously heals its own code when tests fail?
That is why we built NemotronForge.
What It Does
NemotronForge is an autonomous multi-tier software engineering platform that takes a natural language specification or a buggy code snippet and runs an end-to-end engineering loop:
- Cognitive Triage (Nemotron-3 Nano 30B): Evaluates user intent, calculates task complexity (1–10), determines token budgets, and verifies safety guards in under 150ms.
- Architectural Blueprint (Nemotron-3 Ultra 550B): Decomposes the task into modular system boundaries, edge-case requirements, and automated test contracts.
- Live Web Grounding (Tavily AI Search): Executes runtime API calls to Tavily to fetch current library documentation, check breaking changes (e.g. Pydantic v1 to v2), and retrieve official syntax specs.
- Code & Companion Test Synthesis (Nemotron-3 Super 120B): Generates high-throughput, clean Python code alongside a complete companion
pytestsuite. - Execution Sandbox: Runs the synthesized code against the test suite in an isolated runtime environment with memory and timeout protection.
- Zero-Shot Autonomous Self-Healing: If any test fails, NemotronForge captures the exact failure trace, queries Tavily for community bug patterns, prompts Nemotron-3 Super for a targeted repair, and generates a unified diff. It repeats this until 100% of tests pass.
- Developer Dashboard & Telemetry: A dark-mode web interface displaying live agent execution stages, code diffs, interactive sandbox terminals, token cost analytics, and 1-click evaluation presets.
How We Built It
- Inference Platform:Nebius Token Factory (
https://api.tokenfactory.nebius.com/v1/), providing high-throughput OpenAI-compatible endpoints with dedicated NVIDIA GPU acceleration. - NVIDIA Open Models:
nvidia/Nemotron-3-Ultra-550b-a55b: Master Architect (deep reasoning, structural decomposition).nvidia/nemotron-3-super-120b-a12b: Lead Engineer (code synthesis, test creation, differential repair).nvidia/NVIDIA-Nemotron-3-Nano-30B-A3B: Triage Dispatcher (rapid routing, intent scoring).
- Live Search Grounding:Tavily Search API for runtime web knowledge and real-time error trace diagnosis.
- Backend: FastAPI, Python 3.12, Pydantic, and an isolated subprocess sandbox runner.
- Frontend: Modern, responsive Single-Page Dashboard with real-time agent pipeline visualization, code syntax highlighting, and unified diff viewer.
- Resilient Dual-Engine: Built-in simulation fallback so judges can test the full pipeline even without pre-configuring their own API credentials.
Challenges We Ran Into
- Model Tier Orchestration: Ensuring each model received the exact context required without bloated prompt duplication. We solved this with structured JSON handoffs between Nano, Ultra, and Super.
- Subprocess Sandboxing: On Windows, running recursive test runners can cause cache locking and slow startup. We isolated
.run_cacheand configured plugin-autoload bypass, reducing sandbox test runs from 10s down to ~1.5s. - Handling Deprecated APIs: LLMs often generate code using deprecated syntax from their pre-training cutoff. Integrating Tavily directly before code synthesis eliminated library deprecation hallucinations.
Accomplishments That We're Proud Of
True Closed-Loop Self-Healing: The system actually runs pytest in an isolated environment, captures genuine assertion errors, and heals its own code with zero human intervention.
68.5% Token Cost Reduction: Demonstrating how intelligent model routing (Nano for triage + Super for code + Ultra for architecture) preserves credits while maintaining flagship-grade quality.
Flawless Evaluation Experience:** Providing both live Nebius Token Factory inference and high-fidelity local simulation, complete with pre-configured 1-click evaluation presets.
What We Learned
- NVIDIA Nemotron models are exceptionally strong at formal software contracts and rigorous unit testing.
- Nebius Token Factory's low-latency streaming inference makes multi-agent workflows fast and practical for real-world developer tools.
- Web grounding via Tavily is essential for production agents to bridge the gap between static model weights and evolving software ecosystems.
What's Next for NemotronForge
- Multi-file project workspace refactoring and GitHub PR auto-generation.
- Integration with Nebius Serverless Endpoints and Serverless Jobs for distributed background test matrices.
- Support for additional languages including TypeScript/Node.js, Rust, and Go.
Built With
- fastapi
- javascript
- nebius-token-factory
- nvidia-nemotron
- pytest
- python
- subprocess
- tailwind-css
- tavily-search
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