---
summary: "Context: what the model sees, how it is built, and how to inspect it"
read_when:
  - You want to understand what "context" means in Nodmix
  - You are debugging why the model "knows" something (or forgot it)
  - You want to reduce context overhead (/context, /status, /compact)
title: "Context"
---

"Context" is **everything Nodmix sends to the model for a run**. It is bounded by the model's **context window** (token limit).

Beginner mental model:

- **System prompt** (Nodmix-built): rules, tools, skills list, time/runtime, and injected workspace files.
- **Conversation history**: your messages + the assistant's messages for this session.
- **Tool calls/results + attachments**: command output, file reads, images/audio, etc.

Context is _not the same thing_ as "memory": memory can be stored on disk and reloaded later; context is what's inside the model's current window.

## Quick start (inspect context)

- `/status` → quick "how full is my window?" view + session settings.
- `/context list` → what's injected + rough sizes (per file + totals).
- `/context detail` → deeper breakdown: per-file, per-tool schema sizes, per-skill entry sizes, and system prompt size.
- `/context map` → WinDirStat-style treemap image of the current session's tracked context contributors.
- `/usage tokens` → append per-reply usage footer to normal replies.
- `/compact` → summarize older history into a compact entry to free window space.

See also: [Slash commands](/tools/slash-commands), [Token use & costs](/reference/token-use), [Compaction](/concepts/compaction).

## Example output

Values vary by model, provider, tool policy, and what's in your workspace.

### `/context list`

```
🧠 Context breakdown
Workspace: <workspaceDir>
Bootstrap max/file: 12,000 chars
Sandbox: mode=non-main sandboxed=false
System prompt (run): 38,412 chars (~9,603 tok) (Project Context 23,901 chars (~5,976 tok))

Injected workspace files:
- AGENTS.md: OK | raw 1,742 chars (~436 tok) | injected 1,742 chars (~436 tok)
- SOUL.md: OK | raw 912 chars (~228 tok) | injected 912 chars (~228 tok)
- TOOLS.md: TRUNCATED | raw 54,210 chars (~13,553 tok) | injected 20,962 chars (~5,241 tok)
- IDENTITY.md: OK | raw 211 chars (~53 tok) | injected 211 chars (~53 tok)
- USER.md: OK | raw 388 chars (~97 tok) | injected 388 chars (~97 tok)
- HEARTBEAT.md: MISSING | raw 0 | injected 0
- BOOTSTRAP.md: OK | raw 0 chars (~0 tok) | injected 0 chars (~0 tok)

Skills list (system prompt text): 2,184 chars (~546 tok) (12 skills)
Tools: read, edit, write, exec, process, browser, message, sessions_send, …
Tool list (system prompt text): 1,032 chars (~258 tok)
Tool schemas (JSON): 31,988 chars (~7,997 tok) (counts toward context; not shown as text)
Tools: (same as above)

Session tokens (cached): 14,250 total / ctx=32,000
```

### `/context detail`

```
🧠 Context breakdown (detailed)
…
Top skills (prompt entry size):
- frontend-design: 412 chars (~103 tok)
- oracle: 401 chars (~101 tok)
… (+10 more skills)

Top tools (schema size):
- browser: 9,812 chars (~2,453 tok)
- exec: 6,240 chars (~1,560 tok)
… (+N more tools)
```

### `/context map`

Sends an image generated from the latest cached run report. Before a normal message has produced a run report in the session, `/context map` returns an unavailable message instead of rendering an estimate. Rectangle area is proportional to tracked prompt characters:

- injected workspace files
- base system prompt text
- skill prompt entries
- tool JSON schemas

`/context list`, `/context detail`, and `/context json` can still inspect an on-demand estimate when no run report is cached.

## What counts toward the context window

Everything the model receives counts, including:

- System prompt (all sections).
- Conversation history.
- Tool calls + tool results.
- Attachments/transcripts (images/audio/files).
- Compaction summaries and pruning artifacts.
- Provider "wrappers" or hidden headers (not visible, still counted).

## How Nodmix builds the system prompt

The system prompt is **Nodmix-owned** and rebuilt each run. It includes:

- Tool list + short descriptions.
- Skills list (metadata only; see below).
- Workspace location.
- Time (UTC + converted user time if configured).
- Runtime metadata (host/OS/model/thinking).
- Injected workspace bootstrap files under **Project Context**.

Full breakdown: [System Prompt](/concepts/system-prompt).

## Injected workspace files (Project Context)

By default, Nodmix injects a fixed set of workspace files (if present):

- `AGENTS.md`
- `SOUL.md`
- `TOOLS.md`
- `IDENTITY.md`
- `USER.md`
- `HEARTBEAT.md`
- `BOOTSTRAP.md` (first-run only)

Large files are truncated per-file using `agents.defaults.bootstrapMaxChars` (default `12000` chars). Nodmix also enforces a total bootstrap injection cap across files with `agents.defaults.bootstrapTotalMaxChars` (default `60000` chars). `/context` shows **raw vs injected** sizes and whether truncation happened.

When truncation occurs, the runtime can inject an in-prompt warning block under Project Context. Configure this with `agents.defaults.bootstrapPromptTruncationWarning` (`off`, `once`, `always`; default `always`).

## Skills: injected vs loaded on-demand

The system prompt includes a compact **skills list** (name + description + location). This list has real overhead.

Skill instructions are _not_ included by default. The model is expected to `read` the skill's `SKILL.md` **only when needed**.

## Tools: there are two costs

Tools affect context in two ways:

1. **Tool list text** in the system prompt (what you see as "Tooling").
2. **Tool schemas** (JSON). These are sent to the model so it can call tools. They count toward context even though you don't see them as plain text.

`/context detail` breaks down the biggest tool schemas so you can see what dominates.

## Commands, directives, and "inline shortcuts"

Slash commands are handled by the Gateway. There are a few different behaviors:

- **Standalone commands**: a message that is only `/...` runs as a command.
- **Directives**: `/think`, `/verbose`, `/trace`, `/reasoning`, `/elevated`, `/model`, `/queue` are stripped before the model sees the message.
  - Directive-only messages persist session settings.
  - Inline directives in a normal message act as per-message hints.
- **Inline shortcuts** (allowlisted senders only): certain `/...` tokens inside a normal message can run immediately (example: "hey /status"), and are stripped before the model sees the remaining text.

Details: [Slash commands](/tools/slash-commands).

## Sessions, compaction, and pruning (what persists)

What persists across messages depends on the mechanism:

- **Normal history** persists in the session transcript until compacted/pruned by policy.
- **Compaction** persists a summary into the transcript and keeps recent messages intact.
- **Pruning** drops old tool results from the _in-memory_ prompt to free context-window space, but does not rewrite the session transcript - the full history is still inspectable on disk.

Docs: [Session](/concepts/session), [Compaction](/concepts/compaction), [Session pruning](/concepts/session-pruning).

By default, Nodmix uses the built-in `legacy` context engine for assembly and
compaction. If you install a plugin that provides `kind: "context-engine"` and
select it with `plugins.slots.contextEngine`, Nodmix delegates context
assembly, `/compact`, and related subagent context lifecycle hooks to that
engine instead. `ownsCompaction: false` does not auto-fallback to the legacy
engine; the active engine must still implement `compact()` correctly. See
[Context Engine](/concepts/context-engine) for the full
pluggable interface, lifecycle hooks, and configuration.

## What `/context` actually reports

`/context` prefers the latest **run-built** system prompt report when available:

- `System prompt (run)` = captured from the last embedded (tool-capable) run and persisted in the session store.
- `System prompt (estimate)` = computed on the fly when no run report exists (or when running via a CLI backend that doesn't generate the report).

Either way, it reports sizes and top contributors; it does **not** dump the full system prompt or tool schemas.

## Related

<CardGroup cols={2}>
  <Card title="Context engine" href="/concepts/context-engine" icon="puzzle-piece">
    Custom context injection via plugins.
  </Card>
  <Card title="Compaction" href="/concepts/compaction" icon="compress">
    Summarizing long conversations to keep them inside the model window.
  </Card>
  <Card title="System prompt" href="/concepts/system-prompt" icon="message-lines">
    How the system prompt is built and what it injects each turn.
  </Card>
  <Card title="Agent loop" href="/concepts/agent-loop" icon="arrows-rotate">
    The full agent execution cycle from inbound message to final reply.
  </Card>
</CardGroup>
