hal_client: Create a Copilot ACP client

In hal: Agentic Coding Assistants

Create a Copilot ACP client

Description

Creates a new HalClient instance for low-level ACP communication. Most users should use hal_chat() instead.

Usage

hal_client(
  model = NULL,
  cli_path = NULL,
  permission_policy = "auto-allow",
  on_text = NULL,
  on_tool_call = NULL,
  on_thought = NULL,
  quiet = FALSE
)

Arguments

model	Model identifier (e.g., "claude-sonnet-5", "gpt-5.2"). Passed as --model to the CLI at startup. If NULL, falls back to the COPILOT_MODEL environment variable, then the server default.
cli_path	Path to the Copilot CLI binary. If NULL, searches PATH and common install locations.
permission_policy	How to handle tool permission requests: "auto-allow" (default) auto-approves, "auto-deny" auto-denies, "ask" prompts interactively (vscode backend only), or a function receiving permission params. The function returns an ACP option id on copilot, or a string containing "allow"/"deny" on vscode/claude.
on_text	Callback for streaming text chunks: ⁠function(chunk)⁠.
on_tool_call	Callback for tool call events: ⁠function(tool_call)⁠.
on_thought	Callback for thought chunks: ⁠function(chunk)⁠.
quiet	Logical; suppress informational messages (default FALSE).

Value

A HalClient object.

See Also

hal_chat(), hal_available()

Examples

## Not run: 
client <- hal_client()
client$start()
client$handshake()
session <- client$new_session()
client$stop()

## End(Not run)

hal documentation built on Oct. 6, 2026, 5:07 p.m.