Reasoner-Executor-Synthesizer: Scalable Agentic Architecture with Static O(1) Context Window
Ivan Dobrovolskyi · arXiv (Cornell University) · 2026
AI-generated evidence extraction, verified across multiple analytical personas. Not a substitute for the peer-reviewed original.
Methodology & findings
Study design
Formal architectural design with theoretical complexity proof and empirical validation via benchmark testing.
Primary method
Design science methodology with formal architectural specification and empirical validation
Main result
The study demonstrates that the RES architecture achieves O(1) token complexity with respect to dataset size. Specifically, "RES achieves a mean token cost of 1,574 tokens with a standard deviation of only 259 across all 95 successful runs" while "the token cost remains stable whether querying 42,453 articles (cybersecurity) or 16,273,710 articles (medical research), empirically confirming the O(1) behavior established in Theorem 1." At maximum scale, "the naive approach would require approximately 1.9 billion tokens compared to RES's 1,574—a factor of 1.2 million."
Research paradigm
Positivist/engineering - formal theorem proving combined with empirical validation
Author conclusions
The authors conclude: "We presented the Reasoner-Executor-Synthesizer (RES) architecture for building AI agents that are hallucination-free by construction and operate with O(1) LLM token complexity." They further state that "using ScholarSearch, a scholarly research assistant indexing over 130 million articles, we empirically verified Theorem 1 by demonstrating that RES maintains a constant token cost of 1,574±259 tokens across datasets ranging from 42,000 to 16.3 million articles." The authors believe "RES provides a general-purpose pattern for building trustworthy, cost-efficient AI agents across any domain with structured or semi-structured data."
Risk of bias
Limited baseline comparison - only compared against a naive single-prompt baseline with 50 articles, not against state-of-the-art RAG systems; Query selection bias - all 20 queries designed to work with aggregation-based analysis; no evaluation on queries requiring document-level reasoning; Single API source - evaluation limited to Crossref; generalizability to other data sources not empirically tested; Small failure rate - 5 runs failed due to API timeouts (95 of 100 runs successful), but impact not fully analyzed; Single LLM model - only Claude Sonnet tested; no evaluation with other LLM implementations; Selection of query types - all queries amenable to statistical aggregation by design; The evaluation uses a single LLM (Claude Sonnet) for both RES and baseline approaches, which may not generalize to other models. The naive baseline uses only 50 articles, which does not fully explore the scaling characteristics at intermediate dataset sizes. All experiments conducted on a single date (March 14, 2026) without longer-term consistency validation.; Single LLM model tested (Claude Sonnet); Limited baseline comparison (only naive RAG with 50 articles); Single data source (Crossref scholarly articles); Limited query diversity (20 queries across 4 categories); 5 runs per query may be insufficient for statistical robustness; API timeout failures (5 of 100 runs) not fully analyzed
Limitations
- "RES is best suited for analytical queries (counts, trends, comparisons, rankings) whose answers can be derived from aggregated statistics
- Queries that require deep reading of individual documents (e.g., 'summarize the methodology of paper X') call for a different architecture, such as focused RAG or long-context models." Additionally, "The Reasoner's ability to correctly parse complex queries is bounded by the LLM's instruction-following capability" and "the current implementation relies on Crossref's faceted search capabilities
- data sources without built-in aggregation would require the Executor to process records programmatically, though the LLM token cost would remain O(1)."
Open questions raised
- Future work includes: (1) extending the Executor layer to support multi-source federation, (2) adding a caching layer for repeated statistical queries, and (3) formally verifying the hallucination-free property via automated fact-checking of the Executor's output.
- Multi-source federation in the Executor layer
- Caching layer for repeated statistical queries
- Formal verification of the hallucination-free property via automated fact-checking
- Generalization beyond analytical queries to document summarization and deep reading tasks
- Extension to data sources without built-in aggregation capabilities
Explore related topics
Related papers
- Rayyan—a web and mobile app for systematic reviewsMourad Ouzzani · 2016 · 24,664 citations
- Guidance for conducting systematic scoping reviewsMicah D.J. Peters · 2015 · 7,472 citations
- Which academic search systems are suitable for systematic reviews or meta‐analyses? Evaluating retrieval qualities of Google Scholar, PubMed, and 26 other resourcesMichael Gusenbauer · 2019 · 2,116 citations
- Hallucination Rates and Reference Accuracy of ChatGPT and Bard for Systematic Reviews: Comparative AnalysisMikaël Chelli · 2024 · 295 citations
- Artificial intelligence and the conduct of literature reviewsGerit Wagner · 2021 · 275 citations
- Artificial intelligence for literature reviews: opportunities and challengesF. J. Bolaños · 2024 · 188 citations