# `ClaudeAgentSDK.Query`
[🔗](https://github.com/nshkrdotcom/claude_agent_sdk/blob/v0.16.0/lib/claude_agent_sdk/query.ex#L1)

Handles querying Claude Code and processing responses.

This module is responsible for building the appropriate command-line arguments
for different types of Claude Code queries (new queries, continuations, and
resumptions) and delegating to the CLI streaming transport for execution.

All functions in this module return a Stream of `ClaudeAgentSDK.Message` structs.

## SDK MCP Server Support

When SDK MCP servers are detected in options, the query automatically uses
the Client GenServer (which supports bidirectional control protocol) instead
of the simpler Process.stream approach. This is transparent to the caller -
you still get the same Stream interface.

# `continue`

```elixir
@spec continue(String.t() | nil, ClaudeAgentSDK.Options.t()) ::
  Enumerable.t(ClaudeAgentSDK.Message.t())
```

Continues the most recent conversation.

## Parameters

- `prompt` - Optional additional prompt to send (string or nil)
- `options` - Configuration options (see `t:ClaudeAgentSDK.Options.t/0`)

## Returns

A stream of `t:ClaudeAgentSDK.Message.t/0` structs.

## Examples

    ClaudeAgentSDK.Query.continue("Add error handling", %ClaudeAgentSDK.Options{})

# `resume`

```elixir
@spec resume(String.t(), String.t() | nil, ClaudeAgentSDK.Options.t()) ::
  Enumerable.t(ClaudeAgentSDK.Message.t())
```

Resumes a specific conversation by session ID.

## Parameters

- `session_id` - The session ID to resume (string)
- `prompt` - Optional additional prompt to send (string or nil)
- `options` - Configuration options (see `t:ClaudeAgentSDK.Options.t/0`)

## Returns

A stream of `t:ClaudeAgentSDK.Message.t/0` structs.

## Examples

    ClaudeAgentSDK.Query.resume("session-123", "Add tests", %ClaudeAgentSDK.Options{})

# `run`

```elixir
@spec run(String.t() | Enumerable.t(), ClaudeAgentSDK.Options.t(), term() | nil) ::
  Enumerable.t(ClaudeAgentSDK.Message.t())
```

Runs a new query with the given prompt and options.

Automatically detects if SDK MCP servers are present in options and routes
to the appropriate backend:
- SDK MCP servers present → Uses Client GenServer (bidirectional control protocol)
- No SDK MCP servers → Uses CLI-only streaming transport (unidirectional)

## Parameters

- `prompt` - The prompt to send to Claude (string)
- `options` - Configuration options (see `t:ClaudeAgentSDK.Options.t/0`)

## Returns

A stream of `t:ClaudeAgentSDK.Message.t/0` structs.

## Examples

    # Simple query (no SDK MCP)
    ClaudeAgentSDK.Query.run("Write a hello world function", %ClaudeAgentSDK.Options{})

    # With SDK MCP servers (auto-uses Client)
    server = ClaudeAgentSDK.create_sdk_mcp_server(name: "math", tools: [Add])
    options = %Options{mcp_servers: %{"math" => server}}
    ClaudeAgentSDK.Query.run("What is 2+2?", options)

---

*Consult [api-reference.md](api-reference.md) for complete listing*