> ## Documentation Index
> Fetch the complete documentation index at: https://docs.ai-baseline.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Organizations, Knowledge Bases, and Domains

> Select a knowledge base, understand its domain and permissions, and use the versioned REST API or MCP.

AI Baseline retrieves evidence from a selected knowledge base. Each base belongs
to an organization and uses a domain that defines how its material is interpreted
and queried. The API works across knowledge bases; the S\&P 500 examples in these
docs illustrate one base and one domain.

## The three concepts

| Concept | Meaning | S\&P 500 example |
| - | - | - |
| Organization | The owner of a knowledge base. Its URL identifier is `org`. | `baseline` |
| Knowledge base | A specific collection of material with its own identity and access permissions. Its URL identifier is `base`. | `sandp500` |
| Domain | The rules for interpreting and querying the material, including metadata fields, retrieval behavior, and evidence-use instructions. | `sandp_500` |

The organization and base identifiers are stable identifiers, separate from their
display names. Use the exact values provided for your connection.

Each base uses one configured domain. Multiple bases can use the same domain
while keeping separate material and permissions. For example, two private
research bases could both use the `general_purpose` domain; neither base gains
access to the other's documents by sharing that domain. These are illustrative
bases, not additional provisioned endpoints.

## Select a knowledge base

| Interface | URL shape | Authentication |
| - | - | - |
| REST API | `https://api.ai-baseline.dev/{org}/{base}/v2` | API key in `X-API-Key` |
| MCP | `https://mcp.ai-baseline.dev/{org}/{base}` | OAuth authorization for that connection |

The URL selects the base. Credentials authorize access to that selected base;
they do not substitute another dataset behind the same URL. An organization
identifier in a URL identifies the owner, not necessarily the caller's organization.

For the S\&P 500 example:

```text theme={null}
REST: https://api.ai-baseline.dev/baseline/sandp500/v2
MCP:  https://mcp.ai-baseline.dev/baseline/sandp500
```

The complete REST endpoint paths are:

```text theme={null}
POST /{org}/{base}/v2/query
GET  /{org}/{base}/v2/metadata-filters
GET  /{org}/{base}/v2/corpus-overview
```

Do not add the domain ID to these URLs or send it as a query-body selector.
The base's domain is configured for that base. In S\&P 500 responses,
`summary.domain` and the metadata-filter response's `domain` are `sandp_500`,
while the base identifier in the URL is `sandp500`.

## Access and shared knowledge bases

Knowing a base's URL does not grant access. An API key can grant access to several
bases, but each request is checked against the selected base's permissions.
For MCP, authorize a separate connection for each base; an OAuth grant for one
base does not authorize another.

Shared datasets retain their owning organization's URL. A caller from another
organization with an explicit grant uses that same URL. A private base has its
own URL and permissions, even if it uses the same domain as a shared base.

## Adapt the examples to your base

1. Set the REST base URL or MCP connection URL to your supplied organization and
   base identifiers, and authenticate with access to that base.
2. Read `GET /corpus-overview`, or the MCP `get_corpus_overview` tool, to understand
   the base's available material and coverage. Overview is corpus orientation,
   not evidence for factual answers.
3. For REST metadata-filtered queries, call `GET /metadata-filters` on that same
   base. Reuse only supported fields, operators, and values. SEC fields such as
   `sec_ticker` belong to the S\&P 500 example and need not exist in another domain.
4. Ask questions about that base's material using `POST /query` or MCP's
   `retrieve_evidence_context` tool. Preserve the returned evidence instructions
   and citation references when handing the result to a model.

The query modes and response structure use the same API contract across bases.
Available evidence, metadata fields, distributions, and evidence-use instructions
reflect the selected base and domain. Changing a URL does not copy data, change a
domain, or grant permissions.

## API versioning

`v2` identifies the public REST request and response contract. Compatible additions
stay within that major version; breaking contract changes require a new major
version. Keep the explicit version in client configuration.

The REST API version is independent of application releases and domain releases.
It does not pin the base's corpus contents or select a historical dataset.

The MCP connection URL remains unversioned because it identifies the base and its
OAuth resource. Use its exact URL without adding `/v2` or `/mcp`.

Continue with the [REST quickstart](/quickstart) or [MCP connection guide](/connect-mcp).


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.