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Several research systems separate a dynamic question/gap queue (the frontier: what is still to ask) from an accumulated knowledge workspace (the notes: what is known). The deep research loop follows the same split. This page summarizes the systems that implement it. The motivation is shared: a single growing conversation drifts, bloats and stops too early. Keeping what to ask and what is known in two explicit structures lets the agent pick the next step from the gap between them, keeps each context small, and gives a clear point to stop (the frontier is empty or exhausted) before writing.

Stanford STORM

STORM (Synthesis of Topic Outlines through Retrieval and Multi-perspective Questioning) generates Wikipedia-depth, cited reports from scratch. It is the canonical academic example of the split.
  • Pre-writing stage: the work is done before any article text exists. Related topics are surveyed first to discover perspectives, so the questions do not come from the model’s first guess alone.
  • Frontier: simulated expert personas (e.g. academic, critic, engineer) each hold a conversation with a topic expert. The questioner reads the conversation so far and asks the next question, so follow-ups are discovered dynamically and the set of open inquiries grows as a tree.
  • Grounding: the expert side turns each question into search queries, filters untrustworthy sources and answers only from retrieved material, so every answer carries citations.
  • Notes: conversations and snippets are collected and organized into an outline tree (a draft outline first, refined with the conversation content) and an evidence table.
  • Writing: the article is written section by section from the outline and the cited evidence for that section, then polished (e.g. deduplicated, lead section added). Writing starts only once the perspective-driven questions are satisfied.
  • Takeaway for us: diverse question sources (perspectives) widen coverage; the outline is a view of the notes that decides what the report says and in which order.

LangChain Open Deep Research (LangGraph)

LangChain’s open-source deep research agent, built on LangGraph. It separates the control loop from the working notes to avoid token bloat and context drift.
  • Scoping: before research, the agent clarifies the request if needed and turns the conversation into a research brief, the single source of truth for the rest of the run.
  • Supervisor as frontier manager: a planner agent decomposes the brief into discrete, isolated research questions and decides how many sub-agents to run. It reflects after each round to decide whether more research is needed, and it has a bounded number of iterations and parallel sub-agents.
  • Sub-agents: each takes one question into an isolated, short-lived context window with its own search tools and a tool-call budget. Parallel runs are possible because the contexts do not share a history.
  • Compression: a sub-agent ends by compressing its findings into a cleaned summary that keeps the claims and their source URLs and drops the raw pages. Only this goes back to the supervisor.
  • Shared state (notes): the compressed findings are appended to the graph state through a reducer. The supervisor sees notes, not raw tokens.
  • Writing: once the supervisor judges the plan complete, a separate synthesis step writes the final report from the brief and the notes in one pass.
  • Takeaway for us: isolation plus compression keeps the planner’s context small; hard limits on iterations and parallelism bound cost.

DualGraph (arXiv 2026)

A recent paper that formalizes the split as Dual-Graph Co-evolution: two graphs that are updated together as the research proceeds. The description below comes from a secondary summary, not from the paper itself; check the paper before relying on details.
  • Outline Graph (OG): the dynamic frontier. Nodes are planned sections and unresolved sub-questions; edges give structure and dependencies. Each node tracks its citations, so it is visible which aspects still lack empirical evidence.
  • Knowledge Graph (KG): the structured notes. Entities, relations and citation-backed claims are extracted from retrieved pages. Clustering groups related entities and claims.
  • Loop: the agent compares the KG (what is proven) with the OG (what still needs answering). Nodes with no or weak evidence produce the next batch of search queries; new evidence can in turn add, split or close OG nodes. Both graphs change every round, hence “co-evolution”.
  • Takeaway for us: the gap is computed from the two structures rather than judged freely by the model, and the notes can be a graph instead of flat text.

GPT-Researcher

A widely used open-source research framework. It is simpler than the graph systems but keeps the split through a planner/executor pipeline.
  • Planning: a planner agent generates an initial set of research questions or sub-queries from the task (often after a first quick search for context). Queries are expanded dynamically if source validation fails.
  • Execution: one crawler agent per sub-query runs in parallel, scrapes the sources and summarizes each one with the source tracked.
  • Notes: the results are aggregated into an isolated markdown context. Redundant text is pruned and the context is filtered by embedding (cosine) similarity to the query, so only relevant passages stay.
  • Writing: a publisher/writer agent receives only the distilled context plus the source list and writes the report, with citations.
  • Takeaway for us: a cheap, parallel, query-per-source pass with a relevance filter is a good baseline for the extraction step.

What they share

  • Explicit frontier: open questions are a first-class, inspectable structure, not implicit in the chat history.
  • Compressed evidence: raw pages are reduced to cited claims before they reach the planner or the writer.
  • Gap-driven next step: the next queries come from what is missing or unverified, not from the last message.
  • Separate synthesis: the report is written only after exploration ends, from the notes alone.
  • Isolation (STORM, LangGraph): parallel perspectives or sub-agents work in short-lived contexts and report back only distilled results.

Mapping to this project

Comparison