Reference
Glossary
Definitions for the main MARCUS concepts, how they relate to one another, and where they appear.
This glossary reflects the current codebase and current product language. Where a concept is mostly internal, experimental, or only visible in some deployments, that is called out directly.
How To Use This Glossary
Each entry gives you:
- a plain-language definition
- the concepts most closely related to it
- where you are most likely to encounter it in the product
If two terms sound similar, use the Related concepts column first. That is usually the fastest way to understand the difference.
Core Objects
| Term | Definition | Related concepts | Where it appears |
|---|---|---|---|
| Project | The main workspace boundary for documents, chat history, and retrieval scope. | Source, Conversation, Organization | Project list, project page, project-scoped chat, settings |
| Source | A document or imported artifact attached to a project. | Project, Chunk, Briefing | Project source list, upload flows, briefings, Library |
| Source inventory | The visible list of sources inside a project. | Source, Ingestion, Briefing | Main project page |
| Chunk | A stored segment of source text used for retrieval and citation. | Source, Embedding, Retrieval | Internal retrieval pipeline, chunk counts in source detail |
| Embedding | A numerical representation of text used for semantic retrieval. | Chunk, Query, Retrieval | Internal ingestion and retrieval services |
| Corpus | The collection of sources MARCUS is allowed to search in a given scope. Usually this means the sources in one project. | Project, Source, Retrieval | Conceptual term across docs, chat, and knowledge tools |
| Corpus quality | The overall usefulness of the source set for producing grounded answers. | Project, Source, Authority, Coverage | Guides, troubleshooting, project management |
Source Interpretation And Enrichment
| Term | Definition | Related concepts | Where it appears |
|---|---|---|---|
| Briefing | A machine-generated source overview that helps a user judge what a document is and whether it looks usable. | Summary, Key points, Authority score | Source briefing panel, project source views |
| Summary | A short machine-generated description of a source. | Briefing, Key points | Source briefing panel |
| Key points | Short extracted statements that capture the main takeaways of a source. | Summary, Concepts | Source briefing panel |
| Tags | Lightweight labels attached to a source, often derived from analysis or ingestion metadata. | Concepts, Document type | Briefings, Library filters |
| Concepts | Extracted topics, terms, or entities used to connect related material. | Tags, Knowledge graph | Briefings, concept views, enrichment outputs |
| Document type | A classification such as protocol, guideline, note, or policy. | Source, Authority score | Source list, briefing badges, Library |
| Authority score | A 1 to 5 rating describing the likely strength of a source type. | Authority rank, Authority explanation | Source briefing, Library views |
| Authority rank | The normalized authority label shown in user-facing document and library surfaces. | Authority score, Source | Library cards, briefing badges |
| Authority explanation | The human-readable reason MARCUS gives for the source's authority level. | Authority score, Briefing | Source briefing panel |
| Enrichment | Post-ingestion analysis such as summary generation, authority scoring, and concept extraction. | Summary, Key points, Tags | Briefings, library metadata |
| Indexing | The point at which a source becomes available for retrieval after parsing, chunking, and embedding. | Ingestion, Chunk, Retrieval | Upload status, source status |
| Ingestion | The asynchronous pipeline that parses, chunks, embeds, and stores uploaded documents. | Source, Chunk, Enrichment | Upload flows, status indicators, worker pipeline |
| Upload status | The visible state of a source while it is moving through ingestion. | Ingestion, Indexing | Project source list, upload flows |
Chat And Answering
| Term | Definition | Related concepts | Where it appears |
|---|---|---|---|
| Conversation | A saved thread of messages inside a project or organization scope. | Query, Citation, Suggestion chip | Chat history, conversation routes |
| Query | The user question sent into retrieval and generation. | Retrieval, Response style | Chat composer, streamed status messages |
| Retrieval | The process that searches indexed content for relevant chunks before generation. | Chunk, Citation, Coverage indicator | Internal pipeline, streaming status UI |
| Citation | A link from an answer back to a supporting passage or source. | Retrieval, Source, Evidence grounding | Chat answers, shared answers, message detail |
| Coverage indicator | A cue that helps the user judge whether the project likely contains enough evidence for the question asked. | Retrieval, Confidence, Corpus quality | Chat response surfaces |
| Confidence | A system-level estimate or cue related to answer support. It should be read with citations and coverage rather than in isolation. | Coverage indicator, Evidence grounding | Completion metadata and some answer surfaces |
| Response style | The answer framing selected for a query, such as protocol-style or reasoning-oriented output. | Query, Generation | Prompt assembly and streamed planning messages |
| Suggestion chip | A follow-up prompt shown after an answer to help refine or extend the conversation. | Conversation, Query | Chat UI after assistant responses |
| Streaming status | Live status text that tells the user what the system is doing while a streamed answer is being prepared. | Query analysis, Retrieval, Generation | Thinking-state UI during chat streaming |
| Reasoning trace | A stored or inspectable record of retrieval and answer-assembly details used for auditing and debugging. | Retrieval, Response style | Internal diagnostics and contract surfaces |
| Shared answer | A MARCUS answer made visible outside the original chat through a dedicated share flow. | Citation, Share link | Shared answer page, sharing flows |
| Share link | The public or semi-public URL that exposes a shared answer or artifact. | Shared answer, Security model | /shared/[slug] page |
Knowledge And Analysis Surfaces
| Term | Definition | Related concepts | Where it appears |
|---|---|---|---|
| Library | The cross-project document intelligence surface for source exploration. | Source, Authority rank, Concepts | Library page |
| Knowledge graph | A project-level view that shows relationships between sources or concepts. | Concepts, Knowledge page | Knowledge area of the project UI |
| Knowledge page | A synthesized project-level knowledge artifact generated from project material. | Briefing, Corpus synthesis | Knowledge Pages surfaces where enabled |
| Theme analysis | A workflow for identifying, reviewing, or refining recurring themes across a project corpus. | Concepts, Corpus synthesis | Theme review pages where enabled |
| Evidence matrix | A comparison surface that lays evidence from multiple sources side by side. | Source, Citation, Theme analysis | Project matrix routes |
| Corpus synthesis | Cross-document synthesis across an entire project corpus. This exists conceptually and in parts of the system, but user-facing exposure may vary by deployment. | Knowledge page, Theme analysis | Knowledge and synthesis features, feature-dependent |
| Knowledge surface | A broad term for advanced project views that summarize or compare evidence beyond a single answer. | Knowledge graph, Knowledge page, Evidence matrix | Guides and project knowledge routes |
Organization And Access
| Term | Definition | Related concepts | Where it appears |
|---|---|---|---|
| Tenant | The broader isolation boundary used to keep one organization's data separate from another's. | Organization, Membership | Internal authorization and persistence layers |
| Organization | The user-facing team or institutional container for memberships and projects. | Project, Membership, Tenant | Org switcher, settings, route prefixes |
| Membership | A user's relationship to an organization or project. | Organization, Project | Members and invites surfaces |
| Invitation | A pending access grant that lets someone join an organization or project. | Membership, Organization | Invite and join flows |
| Org scope | The currently selected organization context in the app. | Organization, Project | Org-scoped routes, switcher, API scoping |
| Project scope | The subset of the corpus allowed for a given chat, source list, or knowledge view. | Project, Retrieval | Project pages, project chat, source routes |
System, Quality, And Governance
| Term | Definition | Related concepts | Where it appears |
|---|---|---|---|
| Evidence grounding | The principle that answers should be assembled from retrieved project evidence and shown with citations. | Citation, Retrieval, Authority | Chat, concepts docs, evaluation |
| Self-knowledge | MARCUS answering questions about its own capabilities, scope, or behavior. | Query, Conversation | Chat responses to product questions |
| Benchmark | A repeatable evaluation or performance check used to inspect quality, latency, or regressions. | Analytics, Developer surface | Developer page, backend benchmark endpoints |
| Analytics | Usage and operational visibility into how MARCUS is being used. | Costs, Benchmark | Analytics surfaces |
| Costs | The tracked expense associated with running parts of the MARCUS workflow. | Analytics, Generation, Enrichment | Admin cost pages |
| Feature flag | A configuration switch that enables or disables a behavior or UI surface. | Configuration, Deployment | Frontend and backend config |
| Preview environment | A temporary deployment created for validating a change before merge. | Staging, Production | GitHub PR workflows, Vercel, Railway |
| Staging | A pre-production environment used for integrated testing. | Preview environment, Production | Deployment workflows and test commands |
| Production | The live user-facing deployment. | Staging, Preview environment | marcus.surgic.ai and production backend |
A Few Frequently Confused Terms
Project vs Organization
An organization is the larger team or institutional container. A project is the focused workspace inside that organization where the actual source corpus and retrieval boundary live.
Source vs Chunk
A source is the uploaded document. A chunk is one smaller passage MARCUS stores so retrieval can find relevant sections instead of only entire documents.
Briefing vs Knowledge Page
A briefing is about one source. A knowledge page is about a project-level topic or synthesis across multiple sources.
Coverage vs Authority
Coverage answers "did the corpus seem to contain enough evidence for this question?" Authority answers "how strong is this source type relative to the others?"