8 files changed, 157 insertions(+), 33 deletions(-)

M CLAUDE.md
M README.md
M internal/llm/backend.go
M internal/llm/cli_client.go
M internal/llm/client.go
M internal/llmfs/example.go
M internal/llmfs/root.go
A internal/llmfs/system.go

@@ 71,6 71,7 @@ llm9p/
 │       ├── root.go           # Root directory construction
 │       ├── ask.go            # Ask file (shim pattern)
 │       ├── state.go          # Model, temperature files
+│       ├── system.go         # System prompt file
 │       ├── tokens.go         # Read-only token counter
 │       ├── new.go            # Conversation reset trigger
 │       ├── context.go        # Conversation history


@@ 215,11 216,15 @@ This logs all 9P messages sent and received.
 9p -a localhost:5640 write llm/ask "What number did I just mention?"
 9p -a localhost:5640 read llm/ask        # Returns "42"
 
-# Add system message (e.g., persona)
-9p -a localhost:5640 write llm/context "Respond like a pirate"
+# Set system prompt (e.g., persona)
+9p -a localhost:5640 write llm/system "Respond like a pirate"
 9p -a localhost:5640 write llm/ask "Hello"
 9p -a localhost:5640 read llm/ask        # Pirate-style response
 
+# System prompt persists across resets
+9p -a localhost:5640 write llm/new "reset"
+9p -a localhost:5640 read llm/system     # Still "Respond like a pirate"
+
 # Reset conversation
 9p -a localhost:5640 write llm/new "reset"
 ```


@@ 307,8 312,9 @@ The following scenarios have been tested and verified working:
 - [x] `write llm/temperature "0.5"` - Updates temperature setting
 - [x] `write llm/ask "What is 2+2?"` followed by `read llm/ask` - Returns "4"
 - [x] Multi-turn conversation maintains context
-- [x] `write llm/context "Respond like a pirate"` - System message works
-- [x] `write llm/new "reset"` - Clears conversation history
+- [x] `write llm/system "Respond like a pirate"` - System prompt works
+- [x] System prompt persists across conversation resets
+- [x] `write llm/new "reset"` - Clears conversation history (keeps system prompt)
 
 ### Infernode (Inferno OS)
 - [x] `mount -A tcp!127.0.0.1!5640 /n/llm` - Mounts successfully

@@ 141,6 141,12 @@ echo "claude-3-haiku-20240307" > /mnt/llm/model
 # Adjust temperature
 echo "0.5" > /mnt/llm/temperature
 
+# Set a system prompt (persists across conversation resets)
+echo "You are a helpful coding assistant." > /mnt/llm/system
+
+# View current system prompt
+cat /mnt/llm/system
+
 # View conversation history
 cat /mnt/llm/context
 


@@ 161,6 167,7 @@ cat /mnt/llm/_example
 ├── ask              # Write prompt, read response (same file)
 ├── model            # Read/write: current model name
 ├── temperature      # Read/write: temperature float (0.0-2.0)
+├── system           # Read/write: system prompt (persists across resets)
 ├── tokens           # Read-only: last response token count
 ├── new              # Write anything to start fresh conversation
 ├── context          # Read: conversation history; Write: add system message


@@ 177,9 184,10 @@ cat /mnt/llm/_example
 | `ask` | Returns last LLM response | Sends prompt to LLM (sync), stores response |
 | `model` | Returns current model name | Sets model for subsequent requests |
 | `temperature` | Returns current temperature | Sets temperature (0.0-2.0) |
+| `system` | Returns current system prompt | Sets system prompt (persists across resets) |
 | `tokens` | Returns last response token count | Permission denied |
-| `new` | Permission denied | Any write resets conversation state |
-| `context` | Returns JSON conversation history | Appends system message to context |
+| `new` | Permission denied | Any write resets conversation (keeps system prompt) |
+| `context` | Returns JSON conversation history | Appends system message to history |
 | `_example` | Returns usage examples | Permission denied |
 | `stream/ask` | Permission denied | Starts a streaming request |
 | `stream/chunk` | Blocks until next chunk, returns it | Permission denied |

@@ 14,15 14,19 @@ type Backend interface {
 	Temperature() float64
 	// SetTemperature sets the temperature (0.0-2.0)
 	SetTemperature(temp float64) error
+	// SystemPrompt returns the current system prompt
+	SystemPrompt() string
+	// SetSystemPrompt sets the system prompt
+	SetSystemPrompt(prompt string)
 	// LastTokens returns token count from last response
 	LastTokens() int
 	// Messages returns conversation history
 	Messages() []Message
 	// MessagesJSON returns conversation history as JSON
 	MessagesJSON() ([]byte, error)
-	// AddSystemMessage adds a system message
+	// AddSystemMessage adds a system message to conversation history
 	AddSystemMessage(content string)
-	// Reset clears conversation history
+	// Reset clears conversation history (but preserves system prompt)
 	Reset()
 	// Ask sends a prompt and returns the response (blocking)
 	Ask(ctx context.Context, prompt string) (string, error)

@@ 15,14 15,15 @@ import (
 // CLIClient uses the Claude Code CLI for LLM requests.
 // This allows using a Claude Max subscription instead of API tokens.
 type CLIClient struct {
-	mu          sync.RWMutex
-	model       string
-	temperature float64
-	messages    []Message
-	lastTokens  int
-	streaming   bool
-	streamChan  chan string
-	streamDone  chan struct{}
+	mu           sync.RWMutex
+	model        string
+	temperature  float64
+	systemPrompt string
+	messages     []Message
+	lastTokens   int
+	streaming    bool
+	streamChan   chan string
+	streamDone   chan struct{}
 }
 
 // cliResponse represents the JSON response from claude CLI


@@ 85,6 86,20 @@ func (c *CLIClient) SetTemperature(temp float64) error {
 	return nil
 }
 
+// SystemPrompt returns the current system prompt
+func (c *CLIClient) SystemPrompt() string {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.systemPrompt
+}
+
+// SetSystemPrompt sets the system prompt for subsequent requests
+func (c *CLIClient) SetSystemPrompt(prompt string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.systemPrompt = prompt
+}
+
 // LastTokens returns the token count from the last response
 // Note: CLI doesn't provide token counts, so this is always 0
 func (c *CLIClient) LastTokens() int {


@@ 138,9 153,14 @@ func (c *CLIClient) buildPrompt() string {
 	return strings.Join(parts, "\n\n")
 }
 
-// getSystemPrompt extracts system messages as a single string
+// getSystemPrompt builds the full system prompt from dedicated prompt and history
 func (c *CLIClient) getSystemPrompt() string {
 	var systems []string
+	// Add dedicated system prompt first
+	if c.systemPrompt != "" {
+		systems = append(systems, c.systemPrompt)
+	}
+	// Also include system messages from conversation history
 	for _, msg := range c.messages {
 		if msg.Role == "system" {
 			systems = append(systems, msg.Content)

@@ 19,15 19,16 @@ type Message struct {
 
 // Client wraps the Anthropic API client with conversation state
 type Client struct {
-	client      anthropic.Client
-	mu          sync.RWMutex
-	model       string
-	temperature float64
-	messages    []Message
-	lastTokens  int
-	streaming   bool
-	streamChan  chan string
-	streamDone  chan struct{}
+	client       anthropic.Client
+	mu           sync.RWMutex
+	model        string
+	temperature  float64
+	systemPrompt string
+	messages     []Message
+	lastTokens   int
+	streaming    bool
+	streamChan   chan string
+	streamDone   chan struct{}
 }
 
 // NewClient creates a new LLM client


@@ 73,6 74,20 @@ func (c *Client) SetTemperature(temp float64) error {
 	return nil
 }
 
+// SystemPrompt returns the current system prompt
+func (c *Client) SystemPrompt() string {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+	return c.systemPrompt
+}
+
+// SetSystemPrompt sets the system prompt for subsequent requests
+func (c *Client) SetSystemPrompt(prompt string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.systemPrompt = prompt
+}
+
 // LastTokens returns the token count from the last response
 func (c *Client) LastTokens() int {
 	c.mu.RLock()


@@ 118,14 133,21 @@ func (c *Client) Ask(ctx context.Context, prompt string) (string, error) {
 	// Add user message to history
 	c.messages = append(c.messages, Message{Role: "user", Content: prompt})
 
-	// Build the API messages
+	// Build the API messages from conversation history
 	apiMessages := make([]anthropic.MessageParam, 0, len(c.messages))
 	var systemBlocks []anthropic.TextBlockParam
 
+	// Add dedicated system prompt first
+	if c.systemPrompt != "" {
+		systemBlocks = append(systemBlocks, anthropic.TextBlockParam{
+			Text: c.systemPrompt,
+		})
+	}
+
 	for _, msg := range c.messages {
 		switch msg.Role {
 		case "system":
-			// Collect system messages
+			// Also include system messages from conversation history
 			systemBlocks = append(systemBlocks, anthropic.TextBlockParam{
 				Text: msg.Content,
 			})


@@ 197,13 219,21 @@ func (c *Client) StartStream(ctx context.Context, prompt string) error {
 	// Add user message to history
 	c.messages = append(c.messages, Message{Role: "user", Content: prompt})
 
-	// Build the API messages
+	// Build the API messages from conversation history
 	apiMessages := make([]anthropic.MessageParam, 0, len(c.messages))
 	var systemBlocks []anthropic.TextBlockParam
 
+	// Add dedicated system prompt first
+	if c.systemPrompt != "" {
+		systemBlocks = append(systemBlocks, anthropic.TextBlockParam{
+			Text: c.systemPrompt,
+		})
+	}
+
 	for _, msg := range c.messages {
 		switch msg.Role {
 		case "system":
+			// Also include system messages from conversation history
 			systemBlocks = append(systemBlocks, anthropic.TextBlockParam{
 				Text: msg.Content,
 			})

@@ 16,11 16,13 @@ Configuration:
   echo "claude-3-haiku-20240307" > model   # Change model
   cat temperature                # View current temperature (0.0-2.0)
   echo "0.5" > temperature       # Set temperature
+  cat system                     # View current system prompt
+  echo "You are a helpful coding assistant." > system  # Set system prompt
 
 Conversation Management:
   cat context                    # View conversation history (JSON)
-  echo "You are a helpful assistant." > context  # Add system message
-  echo "" > new                  # Reset conversation
+  echo "Additional context..." > context  # Add system message to history
+  echo "" > new                  # Reset conversation (keeps system prompt)
 
 Token Usage:
   cat tokens                     # View tokens from last response


@@ 51,9 53,10 @@ Files:
   ask          Read/write: prompt goes in, response comes out (sync)
   model        Read/write: current model name
   temperature  Read/write: sampling temperature (0.0-2.0)
+  system       Read/write: system prompt (persists across resets)
   tokens       Read-only: token count from last response
-  new          Write-only: any write resets conversation
-  context      Read: JSON history; Write: add system message
+  new          Write-only: any write resets conversation (keeps system prompt)
+  context      Read: JSON history; Write: add system message to history
   _example     Read-only: this help text
   stream/ask   Write-only: starts a streaming request
   stream/chunk Read-only: returns next chunk (blocks), EOF when done

@@ 14,6 14,7 @@ func NewRoot(client llm.Backend) protocol.Dir {
 	root.AddChild(NewAskFile(client))
 	root.AddChild(NewModelFile(client))
 	root.AddChild(NewTemperatureFile(client))
+	root.AddChild(NewSystemFile(client))
 	root.AddChild(NewTokensFile(client))
 	root.AddChild(NewNewFile(client))
 	root.AddChild(NewContextFile(client))

@@ 0,0 1,52 @@
+package llmfs
+
+import (
+	"io"
+	"strings"
+
+	"github.com/NERVsystems/llm9p/internal/llm"
+	"github.com/NERVsystems/llm9p/internal/protocol"
+)
+
+// SystemFile exposes the system prompt (read/write)
+type SystemFile struct {
+	*protocol.BaseFile
+	client llm.Backend
+}
+
+// NewSystemFile creates the system file
+func NewSystemFile(client llm.Backend) *SystemFile {
+	return &SystemFile{
+		BaseFile: protocol.NewBaseFile("system", 0666),
+		client:   client,
+	}
+}
+
+func (f *SystemFile) Read(p []byte, offset int64) (int, error) {
+	content := f.client.SystemPrompt()
+	if content != "" {
+		content += "\n"
+	}
+	if offset >= int64(len(content)) {
+		return 0, io.EOF
+	}
+	n := copy(p, content[offset:])
+	return n, nil
+}
+
+func (f *SystemFile) Write(p []byte, offset int64) (int, error) {
+	prompt := strings.TrimSpace(string(p))
+	f.client.SetSystemPrompt(prompt)
+	return len(p), nil
+}
+
+func (f *SystemFile) Stat() protocol.Stat {
+	s := f.BaseFile.Stat()
+	content := f.client.SystemPrompt()
+	if content != "" {
+		s.Length = uint64(len(content) + 1) // +1 for newline
+	} else {
+		s.Length = 0
+	}
+	return s
+}