# Penumbra

> The runtime for builders working with governed, typed, queryable knowledge graphs.

## Docs

- [Authentication](https://docs.pnbr.io/api-reference/authentication.md): Authenticate Penumbra API requests with a Bearer key, scoped to a project or your organization.
- [Endpoints](https://docs.pnbr.io/api-reference/endpoints.md): The /v1 REST surface, grouped by area.
- [API overview](https://docs.pnbr.io/api-reference/overview.md): The Penumbra REST API: base URL, versioning, and conventions.
- [Planes](https://docs.pnbr.io/concepts/planes.md): How Penumbra separates your canonical knowledge, agent memory, and retired history into distinct planes of the same graph.
- [Connect an agent (MCP)](https://docs.pnbr.io/getting-started/connect-agent.md): Give an AI agent live access to your graph through the Penumbra MCP server.
- [Installation](https://docs.pnbr.io/getting-started/installation.md): Add the Penumbra SDK, set your API key, and create a client.
- [Quickstart](https://docs.pnbr.io/getting-started/quickstart.md): Run the paths that are ready today: read the ontology, search, capture an entity, recall memory, and check decision quality.
- [Build a custom memory layer](https://docs.pnbr.io/guides/custom-memory-layer.md): Use pb.memory out of the box, then fork the default memory shape to capture the kinds of memory your domain needs.
- [Ground an agent before it acts](https://docs.pnbr.io/guides/ground-an-agent.md): Gather context, check its evidence coverage, and confirm it is fit to act on before letting an agent proceed.
- [Ingest a document into the graph](https://docs.pnbr.io/guides/ingest-a-document.md): Upload source material, extract it through a shape, and read the typed entities it produces.
- [Research a domain into your graph](https://docs.pnbr.io/guides/research-a-domain.md): Have an agent research a domain, capture findings into the Research shape, then design a domain shape from what it learned.
- [Semantic git: stage, review, apply, revert](https://docs.pnbr.io/guides/semantic-git.md): Deltas are versioned, inspectable, revertible commits to your knowledge graph. Treat writes the way you treat code.
- [Build agents that understand your domain and act on it reliably](https://docs.pnbr.io/index.md): Penumbra is a compiler and runtime for AI-native businesses.
- [Capture and extract](https://docs.pnbr.io/sdk/capture-extract.md): Write to the graph through governed deltas with pb.capture, pb.extract, and pb.deltas.
- [Context and slices](https://docs.pnbr.io/sdk/context-and-slices.md): Compile scoped context and save reusable views with pb.context and pb.slices.
- [Decision quality](https://docs.pnbr.io/sdk/decision-quality.md): Check whether a region of the graph is fit to act on with pb.dq.
- [Memory](https://docs.pnbr.io/sdk/memory.md): Store and retrieve domain-typed memory as graph state with pb.memory.
- [Ontology and shapes](https://docs.pnbr.io/sdk/ontology-and-shapes.md): Read the active ontology, entity types, and shapes with pb.ontology, pb.types, and pb.shapes.
- [SDK overview](https://docs.pnbr.io/sdk/overview.md): Create a client, understand the pb surface, and handle errors.
- [Search](https://docs.pnbr.io/sdk/search.md): Retrieve across entities and sources with pb.search.
- [Sources](https://docs.pnbr.io/sdk/sources.md): Register source material and read what was extracted from it with pb.sources.
- [Authoring shapes](https://docs.pnbr.io/shapes/authoring.md): Open a session, model your domain, and compile it with the Shapes Workbench tools.
- [Connect the Workbench](https://docs.pnbr.io/shapes/connect.md): Add the Shapes Workbench MCP server to Claude Code, Cursor, or Codex with your Penumbra key.
- [Materialize to a project](https://docs.pnbr.io/shapes/materialize.md): Compile a shape and materialize it to a project so the runtime SDK can read and write against it.
- [Shapes Workbench](https://docs.pnbr.io/shapes/overview.md): The design-time surface where you author the shapes that govern your graph, exposed as an MCP server you connect to your AI client.
- [Feedback and support](https://docs.pnbr.io/support.md): Get a key, report a problem, or share an opinion about where Penumbra should go.

## OpenAPI Specs

- [openapi](https://docs.pnbr.io/api-reference/openapi.json)