System Prompt

System Prompt Construction

Overview

The system prompt is split into two layers for prompt caching efficiency:

1. Static system prompt — Base rules + identity files (SOUL.md, IDENTITY.md, USER.md). Cached and reused across requests.
2. Dynamic context preamble — Prepended to each user message. Contains date/time, memories, skills, and reply context.

This separation means the LLM can cache the system prompt tokens and only process the changing preamble as new input.

Key Files

File	Role
src/system-prompt.ts	getSystemPrompt(), buildContextPreamble(), invalidateSystemPromptCache()

Static System Prompt

getSystemPrompt(identity?) builds the full system prompt by concatenating:

BASE_SYSTEM_PROMPT

The hardcoded base prompt that defines:

• Role: “You are a personal companion”
• Rules:
  • Be concise (Telegram context)
  • Proactively store memories
  • Search broadly when recalling
  • Confirm time/message before creating reminders
  • Explain what/why before self-editing
  • Never deploy without passing tests
  • Never edit files outside src/, cli/, or extensions/
• Telegram interactions: How to use telegram tools, message ID format
• Proactive communication: When to add context beyond the bare minimum
• Identity files: How to use read/edit tools with action: "identity"
• Extensions: How tools and skills work, when to use skill tool actions

Identity Sections

If identity files are loaded, they are appended as sections:

## Identity
<content of IDENTITY.md>

## User
<content of USER.md>

## Soul
<content of SOUL.md>

Note the order: Identity, User, Soul. The Soul section (personality) comes last so it has the strongest influence on the model’s behavior.

Caching

The system prompt is cached in module-level variables. The cache key is a pipe-delimited concatenation of all three identity file contents. invalidateSystemPromptCache() clears the cache (called when identity files are edited via the edit tool or extensions are reloaded).

Dynamic Context Preamble

buildContextPreamble(context) creates a text block prepended to each user message. It contains:

1. Context Header

[Context: Monday, February 24, 2026 at 3:15 PM (America/New_York) | telegram]

Includes the current date/time formatted using Intl.DateTimeFormat in the configured timezone, the message source, and a DEV MODE flag if applicable.

2. Dev Mode Warning

[Running in development -- hot reload is active]

Only present when NODE_ENV=development.

3. Recent Memories

[Recent memories -- use these for context, pattern recognition, and continuity]
- (preference) User prefers dark mode
- (fact) User works at Acme Corp

The 10 most recent memories, regardless of relevance. Gives the agent temporal continuity.

4. Relevant Memories

[Potentially relevant memories]
- (note) Meeting with Bob about the API redesign (87% match)

Up to 5 semantically relevant memories with match percentage. Deduped against recent memories.

5. Active Skills

[Active skills -- follow these instructions when relevant]

### daily-standup
When the user asks for a standup...

Up to 3 skills selected by embedding similarity (threshold 0.35).

6. Reply Context

[Replying to: "what was that thing you mentioned yesterday?"]

When the user replies to a specific message in Telegram, the original message text (truncated to 300 chars) is included.

Date/Time Formatting

Uses Date.toLocaleString() with the configured timezone:

[Current time: 3:15 PM | Monday March 24 2026 | America/New_York | telegram]

Full Prompt Assembly

The complete prompt the LLM sees:

[System prompt]
  BASE_SYSTEM_PROMPT
  ## Identity (if loaded)
  ## User (if loaded)
  ## Soul (if loaded)

[User message]
  [Context: Monday, February 24, 2026 at 3:15 PM (America/New_York) | telegram]
  [Recent memories...]
  [Relevant memories...]
  [Active skills...]
  [Reply context...]

  <actual user message>

The preamble is prepended directly to the user’s message text (no separator).