# How Claude Stores and Uses State Information
## The Question
When Claude receives state information (e.g., "Model color: #ff0000") from an MCP tool, where does it store this information? How does it retrieve it later when you ask to manipulate it?
## The Answer: Conversation Context, Not a Data Structure
**Claude does NOT store state in a separate data structure.** Instead, it uses **conversation context** - the conversation history itself.
### How It Works
1. **Tool Response Becomes Conversation Text**
- When `get_model_color` returns `"Model color: #ff0000"`, this text is added to the conversation history
- It becomes part of the messages Claude can "see" in the current conversation
2. **Claude "Remembers" by Reading Context**
- When you later ask "darken the color," Claude sees the previous message `"Model color: #ff0000"` in the conversation history
- It uses this information to calculate a darker shade
- It's not retrieving from a database - it's reading from the conversation context
3. **No Separate Storage**
- There's no `claude.memory.modelColor = "#ff0000"` variable
- There's no database or key-value store
- Everything is in the conversation messages themselves
### Example Flow
```
User: "What color is the model?"
Claude: [Calls get_model_color tool]
Tool Response: "Model color: #ff0000"
Claude: "The model color is #ff0000 (red)."
[This entire exchange is now in the conversation context]
User: "Darken it a bit"
Claude: [Sees "Model color: #ff0000" in conversation history]
Claude: [Calculates darker shade: #cc0000]
Claude: [Calls change_model_color("#cc0000")]
```
### Important Limitations
1. **Single Conversation Only**
- This "memory" only works within the current conversation
- If you start a new conversation, Claude won't remember the color
- You'd need to query it again or tell Claude what it is
2. **Context Window Limits**
- Claude has a maximum context window (e.g., 200K tokens)
- Very long conversations may exceed this limit
- Older messages may be truncated or forgotten
3. **No Guaranteed Accuracy**
- Claude might misremember or misinterpret information from earlier in the conversation
- It's better to query fresh state when accuracy matters
### Claude's Memory Feature (Optional)
Claude Desktop has an optional **Memory** feature that provides persistent memory across conversations:
- Stores information in a local memory directory
- Can remember preferences, project contexts, and specific data points
- Must be explicitly enabled in settings
- This is separate from the conversation context mechanism
**Note:** Even with Memory enabled, Claude still primarily uses conversation context for immediate recall. Memory is for longer-term persistence across multiple conversations.
### Why This Matters for Your Application
1. **State Can Become Stale**
- If Claude "remembers" `"Model color: #ff0000"` from earlier in the conversation
- But the user manually changed it to `#00ff00` in the browser
- Claude's "memory" (conversation context) is now wrong
- This is why `forceRefresh` exists - to get fresh state
2. **Query Before Manipulating**
- Best practice: Query state right before manipulating it
- This ensures Claude has the most current information
- Example: "What's the current rotation?" → "Rotate it 10 degrees clockwise"
3. **Tool Responses Are Authoritative**
- When Claude receives a tool response, it treats that as the "truth"
- It will use that information for subsequent decisions
- This is why accurate state retrieval is important
### Comparison: Your Server Cache vs. Claude's "Memory"
| Aspect | Your Server Cache | Claude's Conversation Context |
|--------|------------------|------------------------------|
| **Storage** | In-memory Map (`sessionStateCache`) | Conversation message history |
| **Persistence** | Per session, cleared on disconnect | Per conversation, cleared on new conversation |
| **Accuracy** | Can be stale (manual interactions) | Can be stale (outdated tool responses) |
| **Refresh** | `forceRefresh` parameter | Query tool again |
| **Speed** | Instant (~0ms) | Depends on context length |
| **Scope** | All state in one object | Individual tool responses |
### Best Practices
1. **Query State When Needed**
- Don't assume Claude remembers state from earlier
- Query fresh state before making relative changes (e.g., "darken by 10%")
2. **Use forceRefresh After Manual Interactions**
- If user manually rotated model, use `forceRefresh: true` to get accurate state
3. **Be Explicit About State**
- When manipulating state, Claude should query it first
- Example: "Get the current rotation, then rotate it 10 degrees clockwise"
4. **Don't Rely on Long-Term Memory**
- For critical operations, always query current state
- Don't assume Claude remembers from 20 messages ago
### Technical Details: How MCP Tool Responses Work
When Claude calls an MCP tool:
1. **Tool Call**: Claude sends JSON-RPC request to MCP server
```json
{
"method": "tools/call",
"params": {
"name": "get_model_color",
"arguments": {}
}
}
```
2. **Tool Response**: MCP server returns result
```json
{
"content": [
{
"type": "text",
"text": "Model color: #ff0000"
}
]
}
```
3. **Added to Context**: This response becomes part of Claude's conversation context
- Claude sees: `[Tool: get_model_color] → "Model color: #ff0000"`
- This text is now available for Claude to reference
4. **Subsequent Use**: When you ask to manipulate it, Claude:
- Reads the conversation history
- Finds the tool response with the color
- Uses that information to make decisions
### Summary
- **Storage**: Conversation context (message history), not a separate data structure
- **Retrieval**: Claude reads from conversation history when generating responses
- **Persistence**: Only within the current conversation
- **Accuracy**: Can become stale; query fresh state when needed
- **Best Practice**: Query state before manipulating, especially for relative changes
