What is Echo?
The one-paragraph version of what Echo is and the problem it solves.
Echo is the Ontology Layer, the system that ingests an organization's scattered knowledge sources and materializes them as one typed graph queryable by humans and agents through a single API and MCP server.
Most retrieval systems build a search index: they tell you which documents mention a thing. Echo builds an ontology: it tells you what the thing *is*, what it is made of, what it depends on, and what breaks when it changes. An agent that can reason about structure can answer questions a keyword search cannot.
What Echo gives an agent
- Typed entities and relations — a module, a table, and a ticket are different kinds of thing with different questions attached. "This code writes to that table" is a different, answerable fact from "this code reads it."
- Cross-source meaning — the same concept referenced in a ticket, a commit message, and a column name resolves to one entity in the graph rather than three strings that happen to look alike.
- Deterministic structure — code structure (modules, symbols, imports, call paths) is derived by parsers, never by a model, and it is reproducible: the same commit produces the same graph every time. Models run on top of that structure and their output is labeled as interpretation.
- Provenance — every fact carries its origin, including whether it was computed deterministically or interpreted by a model. Every returned claim keeps a resolvable ref.
The three planes
Echo models knowledge in three planes — code, work, and data — then connects them into a single ontology. The cross-plane edges are where Echo excels: anyone can index a repository, but "which service breaks if this column is dropped" is only answerable when the planes share one graph.
One contract, every source
Every source in Echo — code, graph, docs, company docs, work items, commits, PRs, database — flows through the same four operations: discover, search, fetch, and activity. Adding a new source never adds a new endpoint or a new MCP tool. Read the faceted contract for why.
Next: How Echo sees a project.