YeonGyu-Kim d49a75cad5 fix(#130b): enrich filesystem I/O errors with operation + path context
## What Was Broken (ROADMAP #130b, filed cycle #47)

In a fresh workspace, running:

    claw export latest --output /private/nonexistent/path/file.jsonl --output-format json

produced:

    {"error":"No such file or directory (os error 2)","hint":null,"kind":"unknown","type":"error"}

This violates the typed-error contract:
- Error message is a raw errno string with zero context
- Does not mention the operation that failed (export)
- Does not mention the target path
- Classifier defaults to "unknown" even though the code path knows
  this is a filesystem I/O error

## Root Cause (Traced)

run_export() at main.rs:~6915 does:

    fs::write(path, &markdown)?;

When this fails:
1. io::Error propagates via ? to main()
2. Converted to string via .to_string() in error handler
3. classify_error_kind() cannot match "os error" or "No such file"
4. Defaults to "kind": "unknown"

The information is there at the source (operation name, target path,
io::ErrorKind) but lost at the propagation boundary.

## What This Fix Does

Three changes:

1. **New helper: contextualize_io_error()** (main.rs:~260)
   Wraps an io::Error with operation name + target path into a
   recognizable message format:

       "{operation} failed: {target} ({error})"

2. **Classifier branch added** (classify_error_kind at main.rs:~270)
   Recognizes the new format and classifies as "filesystem_io_error":

       else if message.contains("export failed:") ||
               message.contains("diff failed:") ||
               message.contains("config failed:") {
           "filesystem_io_error"
       }

3. **run_export() wired** (main.rs:~6915)
   fs::write() call now uses .map_err() to enrich io::Error:

       fs::write(path, &markdown).map_err(|e| -> Box<dyn std::error::Error> {
           contextualize_io_error("export", &path.display().to_string(), e).into()
       })?;

## Dogfood Verification

Before fix:

    {"error":"No such file or directory (os error 2)","kind":"unknown","type":"error"}

After fix:

    {"error":"export failed: /private/nonexistent/path/file.jsonl (No such file or directory (os error 2))","kind":"filesystem_io_error","type":"error"}

The envelope now tells downstream claws:
- WHAT operation failed (export)
- WHERE it failed (the path)
- WHAT KIND of failure (filesystem_io_error)
- The original errno detail preserved for diagnosis

## Non-Regression Verification

- Successful export still works (emits "kind": "export" envelope as before)
- Session not found error still emits "session_not_found" (not filesystem)
- missing_credentials still works correctly
- cli_parse still works correctly
- All 180 binary tests pass
- All 466 library tests pass
- All 95 compat-harness tests pass

## Regression Tests Added

Inside the main CliAction test function:

- "export failed:" pattern classifies as "filesystem_io_error" (not "unknown")
- "diff failed:" pattern classifies as "filesystem_io_error"
- "config failed:" pattern classifies as "filesystem_io_error"
- contextualize_io_error() produces a message containing operation name
- contextualize_io_error() produces a message containing target path
- Messages produced by contextualize_io_error() are classifier-recognizable

## Scope

This is the minimum viable fix: enrich export's fs::write with context.
Future work (filed as part of #130b scope): apply same pattern to
other filesystem operations (diff, plugins, config fs reads, session
store writes, etc.). Each application is a copy-paste of the same
helper pattern.

## Pattern

Follows #145 (plugins parser interception), #248-249 (arm-level leak
templates). Helper + classifier + call site wiring. Minimal diff,
maximum observability gain.

## Related

- Closes #130b (filesystem error context preservation)
- Stacks on top of #251 (dispatch-order fix) — same worktree branch
- Ground truth for future #130 broader sweep (other io::Error sites)
2026-04-23 01:40:07 +09:00
..

🦞 Claw Code — Rust Implementation

A high-performance Rust rewrite of the Claw Code CLI agent harness. Built for speed, safety, and native tool execution.

For a task-oriented guide with copy/paste examples, see ../USAGE.md.

Quick Start

# Inspect available commands
cd rust/
cargo run -p rusty-claude-cli -- --help

# Build the workspace
cargo build --workspace

# Run the interactive REPL
cargo run -p rusty-claude-cli -- --model claude-opus-4-6

# One-shot prompt
cargo run -p rusty-claude-cli -- prompt "explain this codebase"

# JSON output for automation
cargo run -p rusty-claude-cli -- --output-format json prompt "summarize src/main.rs"

Configuration

Set your API credentials:

export ANTHROPIC_API_KEY="sk-ant-..."
# Or use a proxy
export ANTHROPIC_BASE_URL="https://your-proxy.com"

Or provide an OAuth bearer token directly:

export ANTHROPIC_AUTH_TOKEN="anthropic-oauth-or-proxy-bearer-token"

Mock parity harness

The workspace now includes a deterministic Anthropic-compatible mock service and a clean-environment CLI harness for end-to-end parity checks.

cd rust/

# Run the scripted clean-environment harness
./scripts/run_mock_parity_harness.sh

# Or start the mock service manually for ad hoc CLI runs
cargo run -p mock-anthropic-service -- --bind 127.0.0.1:0

Harness coverage:

  • streaming_text
  • read_file_roundtrip
  • grep_chunk_assembly
  • write_file_allowed
  • write_file_denied
  • multi_tool_turn_roundtrip
  • bash_stdout_roundtrip
  • bash_permission_prompt_approved
  • bash_permission_prompt_denied
  • plugin_tool_roundtrip

Primary artifacts:

  • crates/mock-anthropic-service/ — reusable mock Anthropic-compatible service
  • crates/rusty-claude-cli/tests/mock_parity_harness.rs — clean-env CLI harness
  • scripts/run_mock_parity_harness.sh — reproducible wrapper
  • scripts/run_mock_parity_diff.py — scenario checklist + PARITY mapping runner
  • mock_parity_scenarios.json — scenario-to-PARITY manifest

Features

Feature Status
Anthropic / OpenAI-compatible provider flows + streaming
Direct bearer-token auth via ANTHROPIC_AUTH_TOKEN
Interactive REPL (rustyline)
Tool system (bash, read, write, edit, grep, glob)
Web tools (search, fetch)
Sub-agent / agent surfaces
Todo tracking
Notebook editing
CLAUDE.md / project memory
Config file hierarchy (.claw.json + merged config sections)
Permission system
MCP server lifecycle + inspection
Session persistence + resume
Cost / usage / stats surfaces
Git integration
Markdown terminal rendering (ANSI)
Model aliases (opus/sonnet/haiku)
Direct CLI subcommands (status, sandbox, agents, mcp, skills, doctor)
Slash commands (including /skills, /agents, /mcp, /doctor, /plugin, /subagent)
Hooks (/hooks, config-backed lifecycle hooks)
Plugin management surfaces
Skills inventory / install surfaces
Machine-readable JSON output across core CLI surfaces

Model Aliases

Short names resolve to the latest model versions:

Alias Resolves To
opus claude-opus-4-6
sonnet claude-sonnet-4-6
haiku claude-haiku-4-5-20251213

CLI Flags and Commands

Representative current surface:

claw [OPTIONS] [COMMAND]

Flags:
  --model MODEL
  --output-format text|json
  --permission-mode MODE
  --dangerously-skip-permissions
  --allowedTools TOOLS
  --resume [SESSION.jsonl|session-id|latest]
  --version, -V

Top-level commands:
  prompt <text>
  help
  version
  status
  sandbox
  acp [serve]
  dump-manifests
  bootstrap-plan
  agents
  mcp
  skills
  system-prompt
  init

claw acp is a local discoverability surface for editor-first users: it reports the current ACP/Zed status without starting the runtime. As of April 16, 2026, claw-code does not ship an ACP/Zed daemon entrypoint yet, and claw acp serve is only a status alias until the real protocol surface lands.

The command surface is moving quickly. For the canonical live help text, run:

cargo run -p rusty-claude-cli -- --help

Slash Commands (REPL)

Tab completion expands slash commands, model aliases, permission modes, and recent session IDs.

The REPL now exposes a much broader surface than the original minimal shell:

  • session / visibility: /help, /status, /sandbox, /cost, /resume, /session, /version, /usage, /stats
  • workspace / git: /compact, /clear, /config, /memory, /init, /diff, /commit, /pr, /issue, /export, /hooks, /files, /release-notes
  • discovery / debugging: /mcp, /agents, /skills, /doctor, /tasks, /context, /desktop
  • automation / analysis: /review, /advisor, /insights, /security-review, /subagent, /team, /telemetry, /providers, /cron, and more
  • plugin management: /plugin (with aliases /plugins, /marketplace)

Notable claw-first surfaces now available directly in slash form:

  • /skills [list|install <path>|help]
  • /agents [list|help]
  • /mcp [list|show <server>|help]
  • /doctor
  • /plugin [list|install <path>|enable <name>|disable <name>|uninstall <id>|update <id>]
  • /subagent [list|steer <target> <msg>|kill <id>]

See ../USAGE.md for usage examples and run cargo run -p rusty-claude-cli -- --help for the live canonical command list.

Workspace Layout

rust/
├── Cargo.toml              # Workspace root
├── Cargo.lock
└── crates/
    ├── api/                # Provider clients + streaming + request preflight
    ├── commands/           # Shared slash-command registry + help rendering
    ├── compat-harness/     # TS manifest extraction harness
    ├── mock-anthropic-service/ # Deterministic local Anthropic-compatible mock
    ├── plugins/            # Plugin metadata, manager, install/enable/disable surfaces
    ├── runtime/            # Session, config, permissions, MCP, prompts, auth/runtime loop
    ├── rusty-claude-cli/   # Main CLI binary (`claw`)
    ├── telemetry/          # Session tracing and usage telemetry types
    └── tools/              # Built-in tools, skill resolution, tool search, agent runtime surfaces

Crate Responsibilities

  • api — provider clients, SSE streaming, request/response types, auth (ANTHROPIC_API_KEY + bearer-token support), request-size/context-window preflight
  • commands — slash command definitions, parsing, help text generation, JSON/text command rendering
  • compat-harness — extracts tool/prompt manifests from upstream TS source
  • mock-anthropic-service — deterministic /v1/messages mock for CLI parity tests and local harness runs
  • plugins — plugin metadata, install/enable/disable/update flows, plugin tool definitions, hook integration surfaces
  • runtimeConversationRuntime, config loading, session persistence, permission policy, MCP client lifecycle, system prompt assembly, usage tracking
  • rusty-claude-cli — REPL, one-shot prompt, direct CLI subcommands, streaming display, tool call rendering, CLI argument parsing
  • telemetry — session trace events and supporting telemetry payloads
  • tools — tool specs + execution: Bash, ReadFile, WriteFile, EditFile, GlobSearch, GrepSearch, WebSearch, WebFetch, Agent, TodoWrite, NotebookEdit, Skill, ToolSearch, and runtime-facing tool discovery

Stats

  • ~20K lines of Rust
  • 9 crates in workspace
  • Binary name: claw
  • Default model: claude-opus-4-6
  • Default permissions: danger-full-access

License

See repository root.