docs: add CLI system docs

docs/en/memory/context.mdx

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+---
+title: Short-term Memory
+description: Conversation context — message management, compression strategies, and context operations
+---
+
+Conversation context is the Agent's short-term memory, containing all messages in the current session (user input, Agent replies, tool calls and results). Proper context management is critical for the Agent's reasoning quality and cost control.
+
+## Context Structure
+
+Each conversation turn consists of:
+
+```
+User message → Agent thinking → Tool call → Tool result → ... → Agent final reply
+```
+
+A single turn may include multiple tool calls (controlled by `agent_max_steps`). All tool calls and results are retained in context until compressed or trimmed.
+
+## Key Configuration
+
+| Parameter | Description | Default |
+| --- | --- | --- |
+| `agent_max_context_tokens` | Maximum context token budget | `50000` |
+| `agent_max_context_turns` | Maximum conversation turns in context | `20` |
+| `agent_max_steps` | Maximum decision steps per turn (tool call count) | `15` |
+
+Configurable via `config.json` or the `/config` chat command.
+
+## Compression Strategy
+
+When context exceeds limits, the system automatically compresses to free space. The process has multiple stages:
+
+### 1. Tool Result Truncation
+
+Before each decision loop, the system checks tool call results in historical turns. Results exceeding **20,000 characters** are truncated, keeping only the beginning and end with a truncation notice. Current turn results are not affected.
+
+### 2. Turn Trimming
+
+When conversation turns exceed `agent_max_context_turns`:
+
+- The **oldest half** of complete turns is trimmed (preserving tool call chain integrity)
+- Trimmed messages are summarized by LLM and **written to the daily memory file**
+- Remaining turns stay intact
+
+### 3. Token Budget Trimming
+
+After turn trimming, if tokens still exceed the budget:
+
+- **Fewer than 5 turns**: All turns undergo **text compression** — each turn keeps only the first user text and last Agent reply, removing intermediate tool call chains
+- **5 or more turns**: The **first half** of turns is trimmed again, with discarded content also written to memory
+
+### 4. Overflow Emergency Handling
+
+When the model API returns a context overflow error:
+
+1. All current messages are summarized and written to memory
+2. Aggressive trimming is applied (tool results limited to 10K chars, user text to 10K, max 5 turns)
+3. If still overflowing, the entire conversation context is cleared
+
+## Session Persistence
+
+Conversation messages are persisted to a local database, automatically restored after service restart. Restore strategy:
+
+- Restores the most recent **`max(3, max_context_turns / 6)`** turns
+- Only retains each turn's **user text and Agent final reply**, not intermediate tool call chains
+- Sessions older than **30 days** are automatically cleaned up
+
+## Commands
+
+Use these commands in chat to manage context:
+
+| Command | Description |
+| --- | --- |
+| `/context` | View current context statistics (message count, role distribution, total characters) |
+| `/context clear` | Clear current session context |
+| `/config agent_max_context_tokens 80000` | Adjust context token budget |
+| `/config agent_max_context_turns 30` | Adjust context turn limit |
+
+<Tip>
+  After clearing context, the Agent "forgets" previous conversation content. Content that was already written to long-term memory can still be retrieved via memory search.
+</Tip>

docs/en/memory/index.mdx

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+---
+title: Long-term Memory
+description: CowAgent long-term memory system — file persistence, automatic writing, and hybrid retrieval
+---
+
+Long-term memory is stored in workspace files, persisting across sessions. The Agent loads historical memory on demand via retrieval tools during conversation, and automatically writes conversation summaries to long-term memory when context is trimmed.
+
+## Memory Types
+
+### Core Memory (MEMORY.md)
+
+Stored in `~/cow/MEMORY.md`, containing long-term user preferences, important decisions, key facts, and other information that doesn't fade over time. The Agent reads and writes this file via tools to maintain long-term knowledge.
+
+### Daily Memory (memory/YYYY-MM-DD.md)
+
+Stored in `~/cow/memory/` directory, named by date (e.g., `2026-03-08.md`), recording daily conversation summaries and key events. Files are only created on first write to avoid generating empty files.
+
+## Automatic Writing
+
+The Agent automatically persists conversation content to long-term memory through the following mechanisms:
+
+- **On context trimming** — When conversation turns or tokens exceed the configured limit, the oldest half of the context is trimmed, and the discarded content is summarized by LLM into key information and written to the daily memory file
+- **Daily scheduled summary** — A full summary is automatically triggered at 23:55 every day, ensuring memory is preserved even on low-activity days (skipped if content hasn't changed)
+- **On API context overflow** — When the model API returns a context overflow error, the current conversation summary is saved as an emergency measure
+
+All memory writes run asynchronously in a background thread (LLM summarization + file writing), never blocking normal conversation replies.
+
+## Memory Retrieval
+
+The memory system supports hybrid retrieval modes:
+
+- **Keyword retrieval** — FTS5 full-text index matching with BM25 ranking
+- **Vector retrieval** — Embedding-based semantic similarity search, finds relevant memory even with different wording
+
+The Agent automatically triggers memory retrieval during conversation as needed, incorporating relevant historical information into context. Results are ranked by a combined score (default: 0.7 vector weight + 0.3 keyword weight). Daily memory scores decay over time (30-day half-life), while core memory does not decay.
+
+## First Launch
+
+On first launch, the Agent will proactively ask the user for key information and save it to the workspace (default `~/cow`):
+
+| File | Description |
+| --- | --- |
+| `system.md` | Agent system prompt and behavior settings |
+| `user.md` | User identity information and preferences |
+| `MEMORY.md` | Core memory (long-term) |
+| `memory/YYYY-MM-DD.md` | Daily memory (created on demand) |
+
+<Frame>
+  <img src="https://cdn.link-ai.tech/doc/20260203000455.png" width="800" />
+</Frame>
+
+## Configuration
+
+| Parameter | Description | Default |
+| --- | --- | --- |
+| `agent_workspace` | Workspace path, memory files stored under this directory | `~/cow` |
+| `agent_max_context_tokens` | Max context tokens; when exceeded, content is trimmed and summarized into memory | `50000` |
+| `agent_max_context_turns` | Max context turns; when exceeded, content is trimmed and summarized into memory | `20` |