---
summary: "What the SKYKOI system prompt contains and how it is assembled"
read_when:
  - Editing system prompt text, tools list, or time/heartbeat sections
  - Changing workspace bootstrap or skills injection behavior
title: "System Prompt"
---

# System Prompt

SKYKOI builds a custom system prompt for every koi run. The prompt is **SKYKOI-owned** and does not use the p-coding-koi default prompt.

The prompt is assembled by SKYKOI and injected into each koi run.

## Structure

The prompt is intentionally compact and uses fixed sections:

- **Tooling**: current tool list + short descriptions.
- **Safety**: short guardrail reminder to avoid power-seeking behavior or bypassing oversight.
- **Skills** (when available): tells the model how to load skill instructions on demand.
- **SKYKOI Self-Update**: how to run `config.apply` and `update.run`.
- **Workspace**: working directory (`kois.defaults.workspace`).
- **Documentation**: local path to SKYKOI docs (repo or npm package) and when to read them.
- **Workspace Files (injected)**: indicates bootstrap files are included below.
- **Sandbox** (when enabled): indicates sandboxed runtime, sandbox paths, and whether elevated exec is available.
- **Current Date & Time**: user-local time, timezone, and time format.
- **Reply Tags**: optional reply tag syntax for supported providers.
- **Heartbeats**: heartbeat prompt and ack behavior.
- **Runtime**: host, OS, node, model, repo root (when detected), thinking level (one line).
- **Reasoning**: current visibility level + /reasoning toggle hint.

Safety guardrails in the system prompt are advisory. They guide model behavior but do not enforce policy. Use tool policy, exec approvals, sandboxing, and channel allowlists for hard enforcement; operators can disable these by design.

## Prompt modes

SKYKOI can render smaller system prompts for sub-kois. The runtime sets a
`promptMode` for each run (not a user-facing config):

- `full` (default): includes all sections above.
- `minimal`: used for sub-kois; omits **Skills**, **Memory Recall**, **SKYKOI
  Self-Update**, **Model Aliases**, **User Identity**, **Reply Tags**,
  **Messaging**, **Silent Replies**, and **Heartbeats**. Tooling, **Safety**,
  Workspace, Sandbox, Current Date & Time (when known), Runtime, and injected
  context stay available.
- `none`: returns only the base identity line.

When `promptMode=minimal`, extra injected prompts are labeled **Subkoi
Context** instead of **Group Chat Context**.

## Workspace bootstrap injection

Bootstrap files are trimmed and appended under **Project Context** so the model sees identity and profile context without needing explicit reads:

- `KOIS.md`
- `SOUL.md`
- `TOOLS.md`
- `IDENTITY.md`
- `USER.md`
- `HEARTBEAT.md`
- `BOOTSTRAP.md` (only on brand-new workspaces)

Large files are truncated with a marker. The max per-file size is controlled by
`kois.defaults.bootstrapMaxChars` (default: 20000). Missing files inject a
short missing-file marker.

Internal hooks can intercept this step via `koi:bootstrap` to mutate or replace
the injected bootstrap files (for example swapping `SOUL.md` for an alternate persona).

To inspect how much each injected file contributes (raw vs injected, truncation, plus tool schema overhead), use `/context list` or `/context detail`. See [Context](/concepts/context).

## Time handling

The system prompt includes a dedicated **Current Date & Time** section when the
user timezone is known. To keep the prompt cache-stable, it now only includes
the **time zone** (no dynamic clock or time format).

Use `session_status` when the koi needs the current time; the status card
includes a timestamp line.

Configure with:

- `kois.defaults.userTimezone`
- `kois.defaults.timeFormat` (`auto` | `12` | `24`)

See [Date & Time](/date-time) for full behavior details.

## Skills

When eligible skills exist, SKYKOI injects a compact **available skills list**
(`formatSkillsForPrompt`) that includes the **file path** for each skill. The
prompt instructs the model to use `read` to load the SKILL.md at the listed
location (workspace, managed, or bundled). If no skills are eligible, the
Skills section is omitted.

```
<available_skills>
  <skill>
    <name>...</name>
    <description>...</description>
    <location>...</location>
  </skill>
</available_skills>
```

This keeps the base prompt small while still enabling targeted skill usage.

## Documentation

When available, the system prompt includes a **Documentation** section that points to the
local SKYKOI docs directory (either `docs/` in the repo workspace or the bundled npm
package docs) and also notes the public mirror, source repo, community Discord, and
SKYKOI Skills ([https://SKYKOI.com/skills](https://SKYKOI.com/skills)) for skills discovery. The prompt instructs the model to consult local docs first
for SKYKOI behavior, commands, configuration, or architecture, and to run
`SKYKOI status` itself when possible (asking the user only when it lacks access).
