Fifty Eleven AI
Solving complex problems and using the frontier models to long research tasks.
Core trick
Persists investigation state as a structured dossier that a long-running agent updates over time as new facts arrive.
Description
Solving complex problems and using the frontier models to long research tasks. Not just research or deep search but the ability for it to be done over time while the user is away. If new information is found while the agent is researching it follows it's path to help make its decision. Its not just deep research here is a 2 page paper, it's research over time and allowing new facts to be introduced while that same string of research is ongoing. I wanted to challenge how long I could make the model think.
README excerpt
# Vellum **A durable, multi-agent investigation engine where the dossier is the primary surface, not chat.** Built solo in 5 days for the Built with Opus 4.7 hackathon, Vellum is a durable investigation system for consequential decisions where the primary surface is a structured dossier, not a chat transcript. It is built for questions that should not be answered immediately because the user's framing may already contain unsafe assumptions. Instead of treating the prompt as the ground truth, Vellum gives an agent time, structure, and tools to challenge the premise, investigate the underlying facts, surface blockers, and deliver a case file the user can return to later. The core idea is that many important decisions do not fit well in chat. A user might ask, "What percentage should I offer to settle this credit-card debt?" A normal chatbot may generate a negotiation strategy. Vellum's agent first asks whether that is even the right question: is the debt valid, is it past the statute of limitations, does the collector own the account, and would negotiation accidentally restart liability? In that case, the responsible answer may not be a number at all. It may be to request validation, stop contact, or avoid engaging until facts are established. Vellum turns that kind of work into a dossier. The dossier contains a premise challenge, working theory, investigation plan, sections, sub-investigations, needs-input blocks, decision points, artifacts, and a final debrief. Each secti