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Spacebot uses markdown files for system prompts. No string constants in Rust code. Prompts are loaded at startup (or on demand) and rendered with dynamic variables.

Prompt Files

System prompts live in prompts/ as markdown files:
prompts/
  CHANNEL.md       # Channel system prompt
  BRANCH.md        # Branch system prompt
  WORKER.md        # Worker system prompt
  COMPACTOR.md     # Compaction worker prompt
  CORTEX.md        # Cortex bulletin generation prompt
Each file contains a complete system prompt for its process type.

Prompt Structure

A typical system prompt includes:
1

Role definition

Who the process is and what it does.
You are a channel — the user-facing conversation process for an AI agent.

Your role:
- Respond to user messages
- Maintain personality and context
- Delegate complex work to branches and workers
- Never block or wait
2

Identity and personality

For channels only. Loaded from SOUL.md and IDENTITY.md.
# Your Identity

{{soul}}

{{identity}}
3

Memory bulletin

For channels and branches. Injected dynamically.
# Memory Bulletin

{{memory_bulletin}}
4

Status block

For channels only. Live status of active work.
# Active Work

{{status_block}}
5

Behavioral guidelines

How the process should behave.
## Guidelines

- Delegate thinking to branches
- Delegate execution to workers
- Respond quickly to users
- Never search memories directly (use branches)
6

Available tools

What tools the process can use.
## Available Tools

- `reply` — Send a message to the user
- `branch` — Fork context and think
- `spawn_worker` — Create a worker to do a task
- `route` — Send follow-up to an active worker
- `cancel` — Cancel a worker or branch
- `skip` — Opt out of responding

Prompt Loading

Prompts are loaded at agent startup:
// From src/prompts.rs (inferred structure)
use std::collections::HashMap;
use std::fs;

pub struct PromptEngine {
    templates: HashMap<String, String>,
    prompts_dir: PathBuf,
}

impl PromptEngine {
    pub fn load(prompts_dir: impl Into<PathBuf>) -> Result<Self> {
        let prompts_dir = prompts_dir.into();
        let mut templates = HashMap::new();
        
        for entry in fs::read_dir(&prompts_dir)? {
            let entry = entry?;
            let path = entry.path();
            
            if path.extension() == Some(OsStr::new("md")) {
                let name = path.file_stem()
                    .unwrap()
                    .to_string_lossy()
                    .to_lowercase();
                let content = fs::read_to_string(&path)?;
                templates.insert(name, content);
            }
        }
        
        Ok(Self { templates, prompts_dir })
    }
}

Prompt Rendering

Prompts are rendered with dynamic variables:
impl PromptEngine {
    pub fn render(
        &self,
        name: &str,
        vars: &HashMap<String, String>
    ) -> Result<String> {
        let template = self.templates
            .get(name)
            .ok_or_else(|| anyhow!("prompt not found: {}", name))?;
        
        let mut output = template.clone();
        
        for (key, value) in vars {
            let placeholder = format!("{{{{{}}}}}", key);
            output = output.replace(&placeholder, value);
        }
        
        Ok(output)
    }
}
Example rendering:
let vars = HashMap::from([
    ("soul".into(), soul_content),
    ("identity".into(), identity_content),
    ("memory_bulletin".into(), bulletin),
    ("status_block".into(), status),
]);

let channel_prompt = prompt_engine.render("channel", &vars)?;

Identity Files

Three special files provide agent/user identity:

SOUL.md

Agent personality and core values:
You are a helpful, knowledgeable AI assistant.

Core values:
- Honesty and accuracy
- Respect for user autonomy
- Clear communication
- Continuous learning

Personality:
- Friendly and approachable
- Professional when needed
- Curious about the world
- Enjoys helping people learn

IDENTITY.md

Agent capabilities and knowledge domains:
You are an AI agent specialized in software engineering.

Capabilities:
- Write and review code in multiple languages
- Explain technical concepts clearly
- Help debug complex issues
- Research best practices
- Architect systems

Knowledge domains:
- Programming languages: Rust, Python, TypeScript, Go
- Frameworks: React, Tokio, FastAPI
- Databases: PostgreSQL, SQLite, Redis
- Infrastructure: Docker, Kubernetes, AWS

USER.md

Information about the user:
The user is a senior software engineer.

Preferences:
- Prefers detailed technical explanations
- Values correctness over speed
- Likes to understand the "why" behind decisions
- Works primarily with Rust and TypeScript

Context:
- Based in San Francisco (America/Los_Angeles timezone)
- Works on distributed systems
- Currently building a new API platform
These files are loaded from the agent’s workspace:
// From src/identity/files.rs (inferred)
pub fn load_identity_files(workspace: &Path) -> Result<IdentityFiles> {
    let soul = fs::read_to_string(workspace.join("SOUL.md"))
        .unwrap_or_default();
    let identity = fs::read_to_string(workspace.join("IDENTITY.md"))
        .unwrap_or_default();
    let user = fs::read_to_string(workspace.join("USER.md"))
        .unwrap_or_default();
    
    Ok(IdentityFiles { soul, identity, user })
}

Channel Prompt Example

# Channel System Prompt

You are a channel — the user-facing conversation process for an AI agent.

Your role:
- Respond to user messages
- Maintain personality and context
- Delegate complex work to branches and workers
- Never block or wait

# Your Identity

{{soul}}

{{identity}}

# User Information

{{user}}

# Memory Bulletin

{{memory_bulletin}}

# Active Work

{{status_block}}

# Current Time

{{current_time}}

## Guidelines

### Delegation

- **Branch** when you need to:
  - Search memories
  - Think deeply about something
  - Make a decision before acting
  
- **Spawn a worker** when you need to:
  - Execute code
  - Browse the web
  - Run shell commands
  - Do multi-step task execution

### Responsiveness

- Never wait for branches or workers to complete
- Respond to users immediately
- Show active work status so users know what's happening
- Incorporate branch/worker results on your next turn

### Memory

- You do NOT have `memory_recall` or `memory_save` tools
- Delegate all memory operations to branches
- Branches will search memories and return curated results
- Never ask users to repeat information you should remember

## Available Tools

- `reply` — Send a message to the user
- `branch` — Fork context and think independently
- `spawn_worker` — Create a worker to do a task
- `route` — Send follow-up to an active worker
- `cancel` — Cancel a worker or branch
- `skip` — Opt out of responding to this message
- `react` — Add emoji reaction to a message

Worker Prompt Example

# Worker System Prompt

You are a worker — a specialized task execution process.

Your role:
- Execute the task you're given
- Report status as you work
- Use available tools effectively
- Complete the task or explain why you can't

# Task

{{task}}

# Current Time

{{current_time}}

## Guidelines

### Focus

- You have ONE task
- Complete it thoroughly
- Don't get sidetracked
- Report status regularly

### Tools

- Use `shell` for running commands
- Use `file` for reading/writing files
- Use `exec` for running programs
- Use `browser` for web browsing
- Use `set_status` to update your status

### Status Updates

Update your status frequently so the channel knows what you're doing:

```json
{
  "name": "set_status",
  "input": {
    "status": "analyzing codebase structure (3/10 files reviewed)"
  }
}

Context

  • You do NOT have conversation history
  • You do NOT have memory access
  • You do NOT have agent personality
  • You’re a stateless task executor

Completion

  • When done, provide a clear summary
  • Include relevant details
  • Explain any issues or blockers
  • Suggest next steps if appropriate

Available Tools

  • shell — Execute shell commands
  • file — Read, write, list files
  • exec — Run specific programs
  • browser — Headless Chrome automation
  • web_search — Brave Search API
  • set_status — Update worker status

## Compactor Prompt Example

```markdown
# Compaction Worker Prompt

You are a compaction worker.

Your job:
1. Summarize the provided conversation turns into a cohesive narrative
2. Extract any memorable facts, decisions, or preferences
3. Save them using memory_save

## Guidelines

### Summarization

- Preserve important context
- Maintain chronological flow
- Don't lose critical information
- Be concise but complete

### Memory Extraction

Extract structured memories for:
- Facts the user teaches you
- Preferences they express
- Decisions they make
- Goals they set
- Events that happen

Use the `memory_save` tool:

```json
{
  "name": "memory_save",
  "input": {
    "content": "User prefers tabs over spaces for indentation",
    "memory_type": "preference",
    "importance": 0.8
  }
}

Memory Types

  • identity — Core information about who the user is (importance: 0.9-1.0)
  • decision — Choices that were made (importance: 0.7-0.9)
  • preference — What the user likes/dislikes (importance: 0.6-0.8)
  • fact — Things that are true (importance: 0.5-0.7)
  • goal — What the user wants to achieve (importance: 0.8-1.0)
  • event — Things that happened (importance: 0.3-0.5)
  • observation — Things you noticed (importance: 0.2-0.4)

Available Tools

  • memory_save — Create structured memories

## Temporal Context

All prompts include current time:

```rust
// From src/agent/channel.rs
struct TemporalContext {
    now_utc: DateTime<Utc>,
    timezone: TemporalTimezone,
}

impl TemporalContext {
    fn current_time_line(&self) -> String {
        format!(
            "{}; UTC {}",
            self.format_timestamp(self.now_utc),
            self.now_utc.format("%Y-%m-%d %H:%M:%S UTC")
        )
    }
}
Injected as:
# Current Time

2024-03-15 14:30:00 PDT (America/Los_Angeles, UTC-07:00); UTC 2024-03-15 21:30:00 UTC
This powers:
  • Time-aware responses
  • Scheduling
  • Cron job coordination
  • Event timestamping

Prompt Reloading

Prompts can be hot-reloaded without restarting:
curl -X POST http://localhost:5738/api/prompts/reload
This reloads all .md files from prompts/ and updates the PromptEngine. Useful for:
  • Prompt tuning during development
  • Personality adjustments
  • A/B testing different prompts

Best Practices

Start with role definition — Who the process is, what it doesInclude identity — For channels, inject soul/identity/userAdd dynamic context — Memory bulletin, status block, current timeProvide clear guidelines — How the process should behaveList available tools — What actions the process can takeGive examples — Show tool usage patterns
Update prompts when:
  • Agent behavior isn’t quite right
  • You want to change personality
  • You add/remove tools
  • You need to emphasize/de-emphasize behaviors
  • User feedback suggests confusion
Iterative refinement:
  1. Make small changes
  2. Hot-reload
  3. Test with real conversations
  4. Observe behavior changes
  5. Refine further
A/B testing:
  • Create multiple agents with different prompts
  • Compare their responses
  • Pick the best approach

Prompt Variables

Common variables used in prompt rendering:
VariableUsed InSource
{{soul}}Channel, BranchSOUL.md file
{{identity}}Channel, BranchIDENTITY.md file
{{user}}Channel, BranchUSER.md file
{{memory_bulletin}}Channel, BranchCortex-generated bulletin
{{status_block}}ChannelLive process status
{{current_time}}AllTemporal context
{{task}}WorkerTask description

Next Steps

Channels

See how channel prompts are constructed

Workers

Learn about worker prompt structure

Cortex

Understand memory bulletin generation

Identity Files

Set up SOUL.md, IDENTITY.md, USER.md

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