diff --git a/python/vectorless/cli/__init__.py b/python/vectorless/cli/__init__.py
new file mode 100644
index 00000000..b8d9796f
--- /dev/null
+++ b/python/vectorless/cli/__init__.py
@@ -0,0 +1,5 @@
+"""Vectorless CLI — command-line interface for document intelligence."""
+
+from vectorless.cli.main import app
+
+__all__ = ["app"]
diff --git a/python/vectorless/cli/commands/__init__.py b/python/vectorless/cli/commands/__init__.py
new file mode 100644
index 00000000..8a49cf3c
--- /dev/null
+++ b/python/vectorless/cli/commands/__init__.py
@@ -0,0 +1,25 @@
+"""CLI command modules."""
+
+from vectorless.cli.commands.init import init_cmd
+from vectorless.cli.commands.add import add_cmd
+from vectorless.cli.commands.list_cmd import list_cmd
+from vectorless.cli.commands.info import info_cmd
+from vectorless.cli.commands.remove import remove_cmd
+from vectorless.cli.commands.query import query_cmd
+from vectorless.cli.commands.ask import ask_cmd
+from vectorless.cli.commands.tree import tree_cmd
+from vectorless.cli.commands.stats import stats_cmd
+from vectorless.cli.commands.config_cmd import config_cmd
+
+__all__ = [
+    "init_cmd",
+    "add_cmd",
+    "list_cmd",
+    "info_cmd",
+    "remove_cmd",
+    "query_cmd",
+    "ask_cmd",
+    "tree_cmd",
+    "stats_cmd",
+    "config_cmd",
+]
diff --git a/python/vectorless/cli/commands/add.py b/python/vectorless/cli/commands/add.py
new file mode 100644
index 00000000..4b27f372
--- /dev/null
+++ b/python/vectorless/cli/commands/add.py
@@ -0,0 +1,32 @@
+"""add command — index documents (maps to engine.index)."""
+
+from typing import Optional
+
+import click
+
+
+def add_cmd(
+    path: str,
+    *,
+    recursive: bool = False,
+    fmt: Optional[str] = None,
+    force: bool = False,
+    jobs: int = 1,
+    verbose: bool = False,
+) -> None:
+    """Index a document or directory.
+
+    Args:
+        path: File or directory path.
+        recursive: Index directory recursively.
+        fmt: Force format ("markdown" | "pdf" | None for auto-detect).
+        force: Force re-index existing documents.
+        jobs: Number of parallel indexing jobs.
+        verbose: Show detailed progress.
+
+    Uses:
+        Engine.index(IndexContext)
+        IndexContext.from_path / from_paths / from_dir
+        IndexOptions(mode="force" if force else "default")
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/ask.py b/python/vectorless/cli/commands/ask.py
new file mode 100644
index 00000000..f494fdcf
--- /dev/null
+++ b/python/vectorless/cli/commands/ask.py
@@ -0,0 +1,46 @@
+"""ask command — interactive REPL for multi-turn queries."""
+
+from typing import Optional
+
+import click
+
+
+def ask_cmd(*, doc_id: Optional[str] = None, verbose: bool = False) -> None:
+    """Start an interactive query REPL.
+
+    Args:
+        doc_id: Limit to a specific document.
+        verbose: Show Agent navigation steps.
+
+    Uses:
+        Engine.query() in a loop with user input.
+        Maintains conversation context across turns.
+
+    Built-in commands (prefixed with .):
+        .help       Show available commands
+        .tree       Display current document tree
+        .stats      Show session statistics (LLM calls, tokens, cost)
+        .nav-log    Show navigation log for current conversation
+        .doc <id>   Switch query target document
+        .doc        Show current target document
+        .verbose    Toggle verbose mode
+        .quit       Exit REPL
+    """
+    raise NotImplementedError
+
+
+def _handle_repl_command(line: str) -> bool:
+    """Handle a built-in REPL command (prefixed with .).
+
+    Args:
+        line: Raw input line.
+
+    Returns:
+        True if the command was handled, False if it's a query.
+    """
+    raise NotImplementedError
+
+
+def _print_welcome() -> None:
+    """Print REPL welcome message with available commands."""
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/config_cmd.py b/python/vectorless/cli/commands/config_cmd.py
new file mode 100644
index 00000000..8a119702
--- /dev/null
+++ b/python/vectorless/cli/commands/config_cmd.py
@@ -0,0 +1,63 @@
+"""config command — view and modify configuration."""
+
+from typing import Optional
+
+import click
+
+
+def config_cmd(
+    key: Optional[str] = None,
+    value: Optional[str] = None,
+    *,
+    init_config: bool = False,
+) -> None:
+    """View or modify workspace configuration.
+
+    Args:
+        key: Config key (dot-separated, e.g. "llm.model").
+        value: New value to set. If None, prints current value.
+        init_config: Reset config to defaults.
+
+    Usage:
+        vectorless-cli config                    # show all
+        vectorless-cli config llm.model          # show one key
+        vectorless-cli config llm.model gpt-4o   # set value
+        vectorless-cli config --init             # reset defaults
+
+    Config keys (in .vectorless/config.toml):
+        llm.model           LLM model name
+        llm.api_key         API key (or env VECTORLESS_API_KEY)
+        llm.endpoint        API endpoint
+        retrieval.strategy  agent | pipeline
+        retrieval.max_rounds  navigation budget
+        index.summary       full | selective | lazy | navigation
+        index.compact_mode  true | false
+    """
+    raise NotImplementedError
+
+
+def _load_config(workspace: str) -> dict:
+    """Load config.toml from workspace.
+
+    Args:
+        workspace: Path to .vectorless/ directory.
+
+    Returns:
+        Parsed config dict.
+    """
+    raise NotImplementedError
+
+
+def _save_config(workspace: str, config: dict) -> None:
+    """Save config dict to config.toml.
+
+    Args:
+        workspace: Path to .vectorless/ directory.
+        config: Config dict to serialize.
+    """
+    raise NotImplementedError
+
+
+def _default_config() -> dict:
+    """Return default configuration values."""
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/info.py b/python/vectorless/cli/commands/info.py
new file mode 100644
index 00000000..cee109c7
--- /dev/null
+++ b/python/vectorless/cli/commands/info.py
@@ -0,0 +1,30 @@
+"""info command — show document index details."""
+
+import click
+
+
+def info_cmd(doc_id: str) -> None:
+    """Show detailed information about an indexed document.
+
+    Args:
+        doc_id: Document identifier.
+
+    Uses:
+        Engine.list() -> filter by doc_id
+        Display: title, source, format, node count, depth, leaf count,
+                 total tokens, routing keywords, top-level sections,
+                 indexed timestamp.
+
+    Example output:
+        Document: API Guide (a1b2c3)
+        Source: ./docs/api-guide.md
+        Format: Markdown
+        Tree: 45 nodes, depth 4, 12 leaves
+        Total tokens: 8,234
+        Routing keywords: api, authentication, endpoints, rate-limit
+        Top-level sections:
+          1. Overview (12 leaves)
+          2. Authentication (8 leaves)
+          3. Endpoints (18 leaves)
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/init.py b/python/vectorless/cli/commands/init.py
new file mode 100644
index 00000000..8ddf8324
--- /dev/null
+++ b/python/vectorless/cli/commands/init.py
@@ -0,0 +1,18 @@
+"""init command — initialize .vectorless/ workspace."""
+
+import click
+
+
+def init_cmd(workspace: str) -> None:
+    """Create .vectorless/ directory structure with default config.
+
+    Creates:
+        .vectorless/
+        ├── config.toml        # LLM key/model/endpoint, retrieval strategy
+        ├── data/              # Index data (DocumentTree, ReasoningIndex)
+        └── cache/             # Memo cache
+
+    Args:
+        workspace: Parent directory to create .vectorless/ in.
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/list_cmd.py b/python/vectorless/cli/commands/list_cmd.py
new file mode 100644
index 00000000..4c479bc7
--- /dev/null
+++ b/python/vectorless/cli/commands/list_cmd.py
@@ -0,0 +1,18 @@
+"""list command — list indexed documents."""
+
+import click
+
+
+def list_cmd(*, fmt: str = "table") -> None:
+    """List all indexed documents in the workspace.
+
+    Args:
+        fmt: Output format — "table" or "json".
+
+    Uses:
+        Engine.list() -> List[DocumentInfo]
+
+    Table output:
+        Doc ID | Title | Format | Nodes | Pages | Indexed At
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/query.py b/python/vectorless/cli/commands/query.py
new file mode 100644
index 00000000..f928ab46
--- /dev/null
+++ b/python/vectorless/cli/commands/query.py
@@ -0,0 +1,40 @@
+"""query command — single query (maps to engine.query)."""
+
+from typing import Optional
+
+import click
+
+
+def query_cmd(
+    question: str,
+    *,
+    doc_ids: tuple[str, ...] = (),
+    workspace_scope: bool = False,
+    fmt: str = "text",
+    verbose: bool = False,
+    max_tokens: Optional[int] = None,
+) -> None:
+    """Execute a single query against indexed documents.
+
+    Args:
+        question: Natural-language question.
+        doc_ids: Limit to specific document IDs.
+        workspace_scope: Query across all documents.
+        fmt: Output format — "text" or "json".
+        verbose: Show Agent navigation steps.
+        max_tokens: Max result tokens.
+
+    Uses:
+        Engine.query(QueryContext(question)
+            .with_doc_ids([...])  or  .with_workspace()
+            .with_max_tokens(n))
+        -> QueryResult
+
+    Verbose mode prints Agent navigation:
+        [1/8] Bird's-eye: 3 top-level branches
+        [2/8] Descend → payment-configuration
+        [3/8] GetContent → doc 29139b
+        [4/8] Evaluate → sufficient
+        → Answer: ...
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/remove.py b/python/vectorless/cli/commands/remove.py
new file mode 100644
index 00000000..b4285b60
--- /dev/null
+++ b/python/vectorless/cli/commands/remove.py
@@ -0,0 +1,15 @@
+"""remove command — remove document index."""
+
+import click
+
+
+def remove_cmd(doc_id: str) -> None:
+    """Remove a document from the index.
+
+    Args:
+        doc_id: Document identifier to remove.
+
+    Uses:
+        Engine.remove(doc_id)
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/stats.py b/python/vectorless/cli/commands/stats.py
new file mode 100644
index 00000000..be2d9060
--- /dev/null
+++ b/python/vectorless/cli/commands/stats.py
@@ -0,0 +1,22 @@
+"""stats command — workspace statistics."""
+
+import click
+
+
+def stats_cmd() -> None:
+    """Show workspace statistics.
+
+    Displays:
+        - Workspace path
+        - Number of indexed documents
+        - Total nodes / leaves / tokens
+        - Index size on disk
+        - DocumentGraph info (edges, connected components)
+        - Last indexed timestamp
+
+    Uses:
+        Engine.list() -> count documents
+        Engine.metrics_report()
+        Filesystem scan for size info
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/commands/tree.py b/python/vectorless/cli/commands/tree.py
new file mode 100644
index 00000000..581f8baf
--- /dev/null
+++ b/python/vectorless/cli/commands/tree.py
@@ -0,0 +1,32 @@
+"""tree command — visualize document tree structure."""
+
+from typing import Optional
+
+import click
+
+
+def tree_cmd(
+    doc_id: str,
+    *,
+    depth: Optional[int] = None,
+    show_summary: bool = False,
+    show_keywords: bool = False,
+) -> None:
+    """Visualize the hierarchical tree structure of an indexed document.
+
+    Args:
+        doc_id: Document identifier.
+        depth: Max depth to display (None = full tree).
+        show_summary: Include node summaries in output.
+        show_keywords: Include routing keywords in output.
+
+    Example output:
+        API Guide (a1b2c3) — 45 nodes, 12 leaves
+        1. Overview [routing: api-overview] (12 leaves)
+        ├── 1.1 Introduction
+        ├── 1.2 Authentication [keywords: auth, token, api-key]
+        │   ├── 1.2.1 API Key Setup
+        │   └── 1.2.2 OAuth Flow
+        └── 1.3 Endpoints (18 leaves)
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/main.py b/python/vectorless/cli/main.py
new file mode 100644
index 00000000..844d3803
--- /dev/null
+++ b/python/vectorless/cli/main.py
@@ -0,0 +1,138 @@
+"""CLI application definition and command routing."""
+
+import asyncio
+from typing import Optional
+
+import click
+
+
+@click.group()
+@click.version_option(package_name="vectorless")
+@click.option("--workspace", "-w", default=".vectorless", help="Workspace directory path.")
+@click.pass_context
+def app(ctx: click.Context, workspace: str) -> None:
+    """Vectorless — reasoning-native document intelligence engine."""
+    ctx.ensure_object(dict)
+    ctx.obj["workspace"] = workspace
+
+
+# ── Index commands ──────────────────────────────────────────
+
+@app.command()
+@click.option("--workspace", "-w", default=".", help="Directory to initialize.")
+def init(workspace: str) -> None:
+    """Initialize a .vectorless/ workspace."""
+    raise NotImplementedError
+
+
+@app.command()
+@click.argument("path", type=click.Path(exists=True))
+@click.option("--recursive", "-r", is_flag=True, help="Index directory recursively.")
+@click.option("--format", "fmt", type=click.Choice(["markdown", "pdf"]), help="Force document format.")
+@click.option("--force", is_flag=True, help="Force re-index existing documents.")
+@click.option("--jobs", "-j", default=1, type=int, help="Parallel indexing jobs.")
+@click.option("--verbose", "-v", is_flag=True, help="Show detailed progress.")
+def add(
+    path: str,
+    recursive: bool,
+    fmt: Optional[str],
+    force: bool,
+    jobs: int,
+    verbose: bool,
+) -> None:
+    """Index a document or directory.
+
+    PATH can be a file (.md, .pdf) or a directory.
+    """
+    raise NotImplementedError
+
+
+@app.command("list")
+@click.option("--format", "fmt", type=click.Choice(["table", "json"]), default="table")
+def list_cmd(fmt: str) -> None:
+    """List all indexed documents."""
+    raise NotImplementedError
+
+
+@app.command()
+@click.argument("doc_id")
+def info(doc_id: str) -> None:
+    """Show details of an indexed document."""
+    raise NotImplementedError
+
+
+@app.command()
+@click.argument("doc_id")
+@click.confirmation_option(prompt="Remove this document index?")
+def remove(doc_id: str) -> None:
+    """Remove a document from the index."""
+    raise NotImplementedError
+
+
+# ── Query commands ──────────────────────────────────────────
+
+@app.command()
+@click.argument("question")
+@click.option("--doc", "-d", multiple=True, help="Limit query to specific document IDs.")
+@click.option("--workspace-scope", is_flag=True, help="Query across all documents.")
+@click.option("--format", "fmt", type=click.Choice(["text", "json"]), default="text")
+@click.option("--verbose", "-v", is_flag=True, help="Show Agent navigation steps.")
+@click.option("--max-tokens", type=int, help="Max result tokens.")
+def query(
+    question: str,
+    doc: tuple[str, ...],
+    workspace_scope: bool,
+    fmt: str,
+    verbose: bool,
+    max_tokens: Optional[int],
+) -> None:
+    """Query indexed documents.
+
+    QUESTION is the natural-language question to ask.
+    """
+    raise NotImplementedError
+
+
+@app.command()
+@click.option("--doc", "-d", help="Limit to a specific document ID.")
+@click.option("--verbose", "-v", is_flag=True, help="Show Agent navigation steps.")
+def ask(doc: Optional[str], verbose: bool) -> None:
+    """Interactive query REPL.
+
+    Start a multi-turn conversation with your documents.
+    """
+    raise NotImplementedError
+
+
+# ── Debug / tool commands ───────────────────────────────────
+
+@app.command()
+@click.argument("doc_id")
+@click.option("--depth", "-d", type=int, help="Max depth to display.")
+@click.option("--show-summary", is_flag=True, help="Show node summaries.")
+@click.option("--show-keywords", is_flag=True, help="Show routing keywords.")
+def tree(doc_id: str, depth: Optional[int], show_summary: bool, show_keywords: bool) -> None:
+    """Visualize document tree structure."""
+    raise NotImplementedError
+
+
+@app.command()
+def stats() -> None:
+    """Show workspace statistics."""
+    raise NotImplementedError
+
+
+@app.command("config")
+@click.argument("key", required=False)
+@click.argument("value", required=False)
+@click.option("--init", "init_config", is_flag=True, help="Re-initialize default config.")
+def config_cmd(key: Optional[str], value: Optional[str], init_config: bool) -> None:
+    """View or modify configuration.
+
+    \b
+    vectorless-cli config                    Show all config
+    vectorless-cli config llm.model          Show specific key
+    vectorless-cli config llm.model gpt-4o   Set a value
+    vectorless-cli config --init             Reset to defaults
+    """
+    raise NotImplementedError
diff --git a/python/vectorless/cli/output.py b/python/vectorless/cli/output.py
new file mode 100644
index 00000000..531058a8
--- /dev/null
+++ b/python/vectorless/cli/output.py
@@ -0,0 +1,75 @@
+"""Output formatting — text, json, table."""
+
+from typing import Any, Optional
+from enum import Enum
+
+
+class OutputFormat(Enum):
+    TEXT = "text"
+    JSON = "json"
+    TABLE = "table"
+
+
+def format_result(data: Any, fmt: OutputFormat) -> str:
+    """Format a result dict for terminal output.
+
+    Args:
+        data: Structured data to format.
+        fmt: Target output format.
+
+    Returns:
+        Formatted string ready to print.
+    """
+    raise NotImplementedError
+
+
+def format_documents_table(documents: list[dict]) -> str:
+    """Format a list of documents as a table.
+
+    Columns: Doc ID | Title | Format | Nodes | Pages | Indexed At
+
+    Args:
+        documents: List of document info dicts.
+
+    Returns:
+        Formatted table string (uses comfy-table or rich).
+    """
+    raise NotImplementedError
+
+
+def format_tree(
+    nodes: list[dict],
+    *,
+    max_depth: Optional[int] = None,
+    show_summary: bool = False,
+    show_keywords: bool = False,
+) -> str:
+    """Format document tree as indented tree view.
+
+    Args:
+        nodes: Flat list of tree nodes with parent references.
+        max_depth: Max depth to display.
+        show_summary: Include summaries.
+        show_keywords: Include routing keywords.
+
+    Returns:
+        Indented tree string.
+    """
+    raise NotImplementedError
+
+
+def format_navigation_steps(steps: list[dict]) -> str:
+    """Format Agent navigation steps for verbose mode.
+
+    Args:
+        steps: List of navigation step dicts with action, target, reasoning.
+
+    Returns:
+        Step-by-step navigation log string.
+    """
+    raise NotImplementedError
+
+
+def format_json(data: Any) -> str:
+    """Format data as indented JSON."""
+    raise NotImplementedError