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

# What is CXP?

> A structured context exchange protocol for agents and robots

CXP (Context Exchange Protocol) defines a **portable context package** and a **minimal message set** that lets
agents and robots exchange the context they need to coordinate work — without assuming a specific LLM, tool system,
robot framework, or vendor stack.

***

## The CXP contract

CXP guarantees that context exchange is:

* **Typed** (not a blob): task, memory, world/perception, resources, decisions, policy
* **Composable**: multiple sources can merge without destructive overwrites
* **Traceable**: provenance + timestamps + confidence travel with the data
* **Governed**: policy is attached to context and enforced on expansion/use
* **Actionable**: supports intent + action requests/results
* **Embodied**: supports robot frames, timebases, safety constraints

***

## Transmission modes

### CXP-FULL

Send a complete, structured bundle when bandwidth/tokens are not a concern.

### CXP-SPARSE (recommended)

Send **just-enough context** first, then expand on demand:

* **CONTEXT\_PREVIEW** → minimal summary + `context_refs`
* **CONTEXT\_REQUEST** → receiver requests IDs + desired depth
* **CONTEXT\_EXPAND** → sender returns requested slices only

***

## Minimal message types (v1)

* `CONTEXT_PREVIEW`, `CONTEXT_REQUEST`, `CONTEXT_EXPAND`, `CONTEXT_DIFF`, `CONTEXT_ACK`
* `INTENT_PROPOSE`, `ACTION_REQUEST`, `ACTION_RESULT`
* `SAFETY_EVENT` (robot safety + policy violations)

***

## Why CXP is different

CXP is not “tool calling” and not “RAG”.

It’s a **standardized, governed context layer** that works across:

* agent runtimes (cloud)
* tools/skills/connector systems
* robots (ROS2, MQTT/IoT, embedded gateways)
* multi-agent teams

***

## Example: Preview → Request → Expand

```json theme={null}
{
  "cxp_version": "1.0",
  "mode": "SPARSE",
  "type": "CONTEXT_PREVIEW",
  "task_id": "deal_102",
  "summary": "3-unit rental, underwritten last week",
  "context_refs": ["mem_332", "doc_882"],
  "policy": { "retention_ttl": "2h" }
}
```

```json theme={null}
{ "cxp_version": "1.0", "type": "CONTEXT_REQUEST", "request": ["mem_332"], "depth": "detailed" }
```

```json theme={null}
{ "cxp_version": "1.0", "type": "CONTEXT_EXPAND", "payload": { "mem_332": { "summary": "..." } } }
```