Implementation Plan: Add roo-cli as a Provider

Checklist

• Step 1: Add roo backend definitions to cli_backend.rs
• Step 2: Register roo in all dispatch points
• Step 3: Add --prompt-file support for all prompts
• Step 4: Add auto-detection support
• Step 5: Create preset file
• Step 6: Update documentation
• Step 7: Post-Implementation Validation

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Step 1: Add roo backend definitions to cli_backend.rs

Objective: Create roo() and roo_interactive() methods on CliBackend with unit tests.

Implementation guidance:

• Add roo() method returning CliBackend with command: "roo", args: ["--print", "--ephemeral"], prompt_mode: PromptMode::Arg, prompt_flag: None, output_format: OutputFormat::Text, env_vars: []
• Add roo_interactive() method returning CliBackend with command: "roo", args: [], prompt_mode: PromptMode::Arg, prompt_flag: None, output_format: OutputFormat::Text, env_vars: []
• Follow the exact pattern of existing backends (kiro, pi, opencode)

Test requirements:

• test_roo_backend(): Verify roo() produces roo --print --ephemeral --prompt-file <path> via build_command() (prompt written to temp file)
• test_roo_interactive(): Verify roo_interactive() produces roo "test prompt"
• test_env_vars_default_empty: Add CliBackend::roo() to the existing env_vars emptiness test

Integration with previous work: This is the foundation — all subsequent steps build on these definitions.

Demo: cargo test -p ralph-adapters test_roo_backend passes. The roo() and roo_interactive() constructors return correct CliBackend configurations.

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Step 2: Register roo in all dispatch points

Objective: Wire roo into all the places where backends are resolved from config/names.

Implementation guidance:

• In from_config() (line ~69): Add "roo" => Self::roo() match arm
• In from_name() (line ~235): Add "roo" => Ok(Self::roo()) match arm
• In for_interactive_prompt() (line ~388): Add "roo" => Ok(Self::roo_interactive()) match arm
• In filter_args_for_interactive() (line ~662): Add "roo" arm that filters --print and --ephemeral flags

Test requirements:

• test_from_name_roo(): CliBackend::from_name("roo") returns backend with command "roo"
• test_from_config_roo(): Config { backend: "roo" } creates correct backend
• test_from_config_roo_with_args(): Config with args: ["--provider", "bedrock", "--model", "anthropic.claude-sonnet-4-6"] appends correctly
• test_for_interactive_prompt_roo(): Factory returns roo_interactive() and builds correct command
• test_roo_interactive_mode_removes_print(): build_command("prompt", true) removes --print from args

Integration with previous work: Uses roo() and roo_interactive() from Step 1.

Demo: cargo test -p ralph-adapters from_name_roo and cargo test -p ralph-adapters from_config_roo both pass. Running ralph run -b roo --dry-run (if available) shows the correct command would be spawned.

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Step 3: Add --prompt-file support for all prompts

Objective: All roo prompts are passed via --prompt-file (one code path, no size threshold).

Implementation guidance:

• In build_command(), after the existing Claude large-prompt handling block, add a block for roo:

  if self.command == "roo" {
      // Always write prompt to temp file
      // Add --prompt-file <path> to args (no positional prompt)
      // Return temp file handle to keep it alive
  }
  

• This is simpler than conditional logic — one path, no 7000-char threshold
• Roo natively reads from --prompt-file (verified working for both small and large prompts)
• Fallback to positional arg only if temp file creation fails

Test requirements:

• test_roo_uses_prompt_file(): Any prompt results in --prompt-file arg and temp file
• test_roo_prompt_file_content(): Verify temp file contains the full prompt text
• test_roo_prompt_file_fallback(): Verify positional arg is used if temp file creation fails

Integration with previous work: Modifies build_command() which uses roo() backend from Step 1.

Demo: cargo test -p ralph-adapters test_roo_uses_prompt_file passes. All prompts use --prompt-file.

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Step 4: Add auto-detection support

Objective: Enable roo in auto-detection when cli.backend: auto is configured.

Implementation guidance:

• In auto_detect.rs, add "roo" at the end of DEFAULT_PRIORITY array
• detection_command("roo") should return "roo" (default behavior, no special mapping needed)
• In NoBackendError::fmt(), add " • Roo CLI: https://github.com/RooVetGit/Roo-Code" to the install suggestions

Test requirements:

• test_detection_command_roo(): detection_command("roo") returns "roo"
• test_default_priority_includes_roo(): DEFAULT_PRIORITY contains "roo"
• test_default_priority_roo_after_pi(): "roo" comes after "pi" (last position)
• Update test_no_backend_error_display(): Verify error message includes "Roo CLI"

Integration with previous work: Independent of Steps 1-3. Uses only auto_detect.rs.

Demo: cargo test -p ralph-adapters detection_command_roo passes. The error message for missing backends includes roo.

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Step 5: Create preset file

Objective: Create presets/minimal/roo.yml as a ready-to-use configuration.

Implementation guidance:

• Copy presets/minimal/kiro.yml as the starting point
• Change cli.backend from "kiro" to "roo"
• Keep all other settings identical (event_loop, core guardrails, hats)
• Update the comment header to reference Roo Code CLI

Test requirements:

• Verify YAML is valid: python3 -c "import yaml; yaml.safe_load(open('presets/minimal/roo.yml'))"
• Verify cli.backend is "roo" in the file

Integration with previous work: Uses the backend name registered in Steps 1-2.

Demo: cat presets/minimal/roo.yml shows a valid configuration. ralph run --preset roo -- --provider bedrock ... would use roo as the backend.

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Step 6: Update documentation

Objective: Update code documentation to reflect roo as a supported backend.

Implementation guidance:

• In crates/ralph-adapters/src/lib.rs, update the crate-level doc comment to include - Roo (Roo Code) in the list of supported backends
• Ensure all new public methods have doc comments explaining their purpose

Test requirements:

• cargo doc -p ralph-adapters --no-deps completes without warnings

Integration with previous work: References all work from Steps 1-5.

Demo: cargo doc builds cleanly. The ralph-adapters documentation lists Roo as a supported backend.

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Step 7: Post-Implementation Validation

Objective: Verify the complete implementation works end-to-end.

Validation checklist:

• cargo test -p ralph-adapters — All tests pass (existing + new roo tests)
• cargo test — Full project test suite passes (no regressions)
• cargo build — Clean build with no warnings
• cargo doc -p ralph-adapters --no-deps — Documentation builds cleanly
• YAML validation: presets/minimal/roo.yml is valid
• Manual E2E (if roo is configured): ralph run -b roo -- --provider bedrock --aws-profile roo-bedrock --aws-region us-east-1 --model anthropic.claude-sonnet-4-6 --max-tokens 64000 -p "Create hello.txt with Hello World" completes at least one iteration

Demo: Full end-to-end demonstration:

1. Show cargo test -p ralph-adapters with all roo tests passing
2. Show presets/minimal/roo.yml contents
3. Show ralph run -b roo starting and executing an iteration with roo backend