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

# Agent Context

# Agent Context

This page explains context in the openboa `Agent` runtime.

Use this page when you want to answer:

* what the prompt contains
* what the prompt does not contain
* why the session is the truth instead of the context window
* what retrieval candidates mean
* what context pressure is for

## The core rule

The session is durable truth.

The prompt is a bounded view assembled for one wake.

That is the most important context rule in the runtime.

## Why this rule exists

Compacted summaries and prompt-local context are useful, but they are not good enough to be the only truth.

Future wakes may need:

* old user messages
* prior shell evidence
* earlier tool results
* the lead-up to a blocked action

If those are only preserved as one summary, the runtime becomes brittle.

## The context model

```mermaid theme={null}
flowchart TD
  A["Session events"] --> D["Harness context assembly"]
  B["Runtime artifacts"] --> D
  C["Retrieval candidates"] --> D
  D --> E["bounded prompt view"]
  E --> F["provider run"]
  F --> G["new events and artifacts"]
  G --> A
```

This means the prompt is assembled, used, and discarded.
The durable objects remain.

## What goes into prompt context

Typical prompt context includes:

* recent conversation continuity
* selected runtime notes
* active outcome posture
* current environment and resource posture
* retrieval candidates for prior truth

What matters is not that everything is loaded.
What matters is that the runtime can reopen what it needs.

## Retrieval candidates are not truth

Retrieval candidates are hints.

They exist to tell the model:

* which prior session may matter
* which memory source may matter
* which exact reread tool is the right next step

They should not be confused with canonical truth.

The canonical truth still lives in:

* session events
* runtime artifacts
* durable memory surfaces

## Reread versus trust

The Agent should prefer:

1. find a relevant candidate
2. reopen the underlying truth
3. act using the reopened evidence

instead of trusting one compacted summary forever.

That is why retrieval and `session_get_events` style reread exist.

## Context pressure

The runtime also tracks context pressure.

Context pressure answers questions like:

* how much recent history fit into this wake
* how much was dropped
* whether protected continuity had to be preserved
* whether the model should prefer reread instead of broad continuation

## Current behavior under pressure

When pressure is high, the runtime can bias the Agent toward:

* `session_describe_context`
* retrieval and reread
* read-first inspection
* narrower next steps

instead of broad, assumption-heavy continuation.

## Design rule

Do not treat context engineering and truth storage as the same problem.

In openboa:

* truth storage belongs to sessions and durable artifacts
* context engineering belongs to the harness

That separation keeps the runtime flexible as models change.

## Related reading

* [Agent Runtime](../agent-runtime.md)
* [Agent Resilience](./resilience.md)
* [Agent Harness](./harness.md)
* [Agent Sessions](./sessions.md)
* [Agent Memory](./memory.md)
* [Agent Tools](./tools.md)