Cloudflare delivery
An assets-only Cloudflare Worker serves the application. The verification work runs on the user’s device, so serving the interface does not require a hosted inference or bibliography-processing backend.
RESEARCH INTEGRITY / AGENT TOOLS
Give every reference an evidence trail.
Citation verification for researchers and AI agents. RefExists checks scholarly records, matches titles and authors, and explains the evidence behind each result.
RefExists
Released · MITDSL4-developed open-source tool. Verification establishes whether a reference exists and matches, not whether it supports a claim.
THE PRODUCT
What it solves.
A plausible citation can still contain a fabricated identifier, mismatched authors or a retracted paper. RefExists turns a bibliography into inspectable registry checks, helping people review sources and agents check references before returning them.
THE ENGINEERING
How it works.
The same JavaScript verification engine runs in the browser and through a local, keyless Model Context Protocol (MCP) server. It queries Crossref, DataCite, DOI infrastructure, OpenAlex, PubMed and Open Library, preserving the difference between a failed network request and a missing record. Individual lookups go to the registries; the bibliography is not uploaded to a DSL4 backend.
CLOUDFLARE & PRODUCT ARCHITECTURE
Inside the system.
Evidence, not a confidence badge
Identifier resolution and metadata matching expose the underlying registry evidence. Network failures remain inconclusive; a missing record is a reason to investigate, not proof of fabrication.
A tool inside the agent workflow
The local MCP server exposes verify_citations using the shared engine. This makes verification reusable in agent workflows without creating a second, divergent implementation.