[cua-bench] feat: implement computer provider for remote environment support

[rowingchenn]

Summary

Implement the computer provider type that was already documented but not functional. This enables running CUA-Bench tasks against remote Computer environments (e.g., remote macOS/Windows VMs via CUA Computer API).

Motivation

The provider_type parameter already documented "computer" as a valid option:

provider_type: Provider type ("simulated", "webtop", "native", "computer", None).

However, only simulated/webtop were actually implemented—computer was ignored. This PR implements the computer provider to connect to remote Computer API endpoints, aligning CUA-Bench with CUA's decoupled agent-environment architecture.

Changes

1. ProviderType Enum

class ProviderType(Enum):
    SIMULATED = "simulated"
    WEBTOP = "webtop"
    NATIVE = "native"
    COMPUTER = "computer"

Replaces string-based checking with type-safe enum for all documented provider types.

2. Provider Resolution

provider_value = provider_type or os.environ.get("CUA_PROVIDER", "native")

Supports configuration via --provider-type argument or CUA_PROVIDER env var.

3. Pre-flight Validation

if is_computer:
    if not os.environ.get("CUA_ENV_API_URL"):
        raise ValueError("For computer provider, CUA_ENV_API_URL must be set.")

Fail fast with clear error when required config is missing.

4. Network Configuration

network_name = f"cua-task-{task_id}" if is_native else None
container_network = network_name if network_name else "host"

• Native: Creates dedicated Docker network for agent ↔ env container communication
• Computer: Uses host network so agent container can reach remote API endpoints

5. API URL Routing

if provider == ProviderType.COMPUTER:
    api_url = os.environ.get("CUA_ENV_API_URL", "")
else:
    api_url = f"http://{self.env_hostname}:{config.get('internal_api_port', 5000)}"

• Computer: URL from environment variable (user-configured remote endpoint)
• Native: URL uses Docker network hostname for container-to-container communication

6. Code Quality

Introduced is_native flag to replace verbose not is_simulated and not is_computer patterns.

Usage

Example: Remote Windows Environment

#!/bin/bash
export CUA_ENV_API_URL="http://34.186.160.160:8000"
export CUA_ENV_TYPE="windows"

cb run task ./tasks/magic_tower \
    --agent cua-agent \
    --model openai/computer-use-preview \
    --provider-type computer

Provider Comparison

Provider	Environment	Network	Use Case
native	Local Docker containers	Dedicated network	Self-contained local testing
simulated	Lightweight HTML/CSS desktop	Host network	Quick preview without Docker
computer	Remote cua-computer-server VM	Host network	Client-server separated deployment

Backward Compatibility

Fully backward compatible. Default behavior unchanged (native if not specified).

Test Plan

Tested:

• computer provider with remote Windows environment (http://34.186.160.160:8000)
• CLI --provider-type computer argument
• Environment variable configuration (CUA_ENV_API_URL, CUA_ENV_TYPE)
• Agent container successfully connects to remote Computer API

Not tested (unchanged logic):

• native provider - no changes to existing flow
• simulated provider - only added to provider type checks, logic unchanged

[vercel]

@rowingchenn is attempting to deploy a commit to the Cua Team on Vercel.

A member of the Team first needs to authorize it.