# CTXPKG — The Open Standard for Portable Agent Context

> CTXPKG is an open, vendor-neutral file format (.ctxpkg) for packaging AI-agent
> knowledge as a typed, signed, composable knowledge graph. It answers the
> question the agent stack left open: "What is true about this system, who says
> so, and can I verify it?" — complementary to MCP (tool invocation) and Agent
> Skills (procedural instructions).

Key facts:
- A .ctxpkg is one JSON document: manifest (identity, SHA-256 integrity,
  provenance, Ed25519 signature) + content.context_graph (typed nodes/edges).
- Node types: fact, pattern, insight, convention, gotcha, decision, finding,
  episode, code_symbol, session, policy, … (extensible registry).
- Edge types: supports, contradicts, supersedes, elaborates, depends_on, … 
- Three conformance levels: 1 Basic (flat nodes, any JSON tool), 2 Graph
  (typed edges, SemVer deps, graph-merge composition), 3 Cognitive (activation
  energy, Hebbian weights, temporal decay).
- Composition: deterministic graph union; conflicts surface via contradicts
  edges; supersedes deactivates (never deletes) older nodes.
- Scoped names: @namespace/name; SemVer versions; immutable published artifacts.
- Registry protocol: open HTTP API (catalog, search, detail, download, signed
  publish with mandatory server-side secret scanning). Anyone can run one.

## Specification
- [Spec versions](https://ctxpkg.org/spec/): v2 current draft, v1 superseded
- [CTXPKG v2 specification](https://ctxpkg.org/spec/v2/): normative, RFC-2119
- [JSON Schemas](https://ctxpkg.org/schema/): draft 2020-12, downloadable
- [v2 schema file](https://ctxpkg.org/schemas/context-package-v2.schema.json)

## Ecosystem
- [Registry protocol](https://ctxpkg.org/registry/): run your own registry
- [Conformance](https://ctxpkg.org/conformance/): level checklists and claim rules
- [Governance](https://ctxpkg.org/governance/): RFC process, shared-governance trigger
- [RFCs](https://ctxpkg.org/rfcs/): proposal index + template; RFC 0001 (ZIP container) and RFC 0002 (provenance attestations) are open for comments
- [Adopt](https://ctxpkg.org/adopt/): playbook for tool authors — reader in a day, writer in a week, registry from the protocol
- [Vision](https://ctxpkg.org/vision/): the governed context supply chain — law (this standard), distribution (registries), enforcement (context engines)
- [Manifesto](https://ctxpkg.org/manifesto/): the six principles

## Implementations
- [lean-ctx](https://leanctx.com): reference implementation (create, sign, verify, merge, install)
- [ctxpkg.com](https://ctxpkg.com): public registry (browse, publish, install)