B2C Debug Skill Skill | Agent Skills

B2C Debug Skill

Debug server-side scripts on Salesforce B2C Commerce instances — set breakpoints, step through code, and inspect variables in SFRA controllers, hooks, jobs, and custom APIs.

Prefer MCP debugging when available: debug_control resumes/steps; debug_inspect reads stacks and variables; debug_evaluate evaluates expressions. See skill://mcp/debugger/SKILL.md for the MCP workflow. Use the CLI for a requested terminal session or when MCP is unavailable.

b2c debug provides a Debug Adapter Protocol (DAP) debug adapter for IDEs. For terminal or headless use without the MCP tools, b2c debug cli also offers an interactive REPL and a JSONL --rpc mode.

Tip: If b2c is not installed globally, use npx @salesforce/b2c-cli instead (e.g., npx @salesforce/b2c-cli debug cli).

Configuration & Authentication

The CLI resolves the target instance and debugger credentials from environment variables (including project .env), the selected project-local or shared dw.json, and configuration plugins. It does not search parent directories. package.json supplies only non-sensitive defaults; ~/.mobify supplies MRT credentials, not debugger credentials. Flags like --server, --username, and --password are usually unnecessary — only pass them to override what's auto-detected.

Run b2c setup inspect to see the resolved configuration and which source provided each value (use --json for scripting; keep secrets masked unless the user explicitly requests their values). For precedence rules and troubleshooting, see the b2c-cli:b2c-config skill.

For MCP debugging, pass projectDirectory to debug_start_session whenever the MCP server may have been launched outside the project. The tool uses that root to load the project's .env and default dw.json; pass configPath to select a different primary dw.json-format file and instanceName to select a named instance from the primary or shared default file. Cartridge discovery and local/server source mapping default to projectDirectory; pass cartridgeDirectory only when the cartridges live under a different root. The start call captures this information in resolution, which debug_list_sessions returns without requiring the caller to repeat it. The MCP server controls its SDAPI client identity internally, so callers do not pass a debugger client ID.

Prerequisites

Basic Auth credentials for a BM user with WebDAV_Manage_Customization: a username and either the account password or a WebDAV File Access and UX Studio access key

Interactive Debugging

Start a Debug Session

# Start interactive debugger
b2c debug cli

# Specify cartridge directory for source mapping
b2c debug cli --cartridge-path ./cartridges

# Use a custom client ID (for concurrent sessions)
b2c debug cli --client-id my-session

Set Breakpoints

In the REPL:

break Cart.js:42
break Checkout.js:100 if basket.totalGrossPrice > 100
breakpoints
delete 1

Inspect State When Halted

stack
vars
members basket.productLineItems
eval basket.productLineItems.length
eval request.httpParameterMap.get("pid").stringValue

Control Execution

continue
step
stepin
stepout

Thread Management

threads
thread 5
frame 2

RPC Mode (Headless / Agent Use)

For headless scripts, agents, and programmatic integration, use --rpc mode. Commands and responses are JSONL (one JSON object per line) on stdin/stdout.

b2c debug cli --rpc

Send Commands

{"id": 1, "command": "set_breakpoints", "args": {"breakpoints": [{"file": "Cart.js", "line": 42}]}}
{"id": 2, "command": "get_stack"}
{"id": 3, "command": "get_variables", "args": {"scope": "local"}}
{"id": 4, "command": "evaluate", "args": {"expression": "basket.totalGrossPrice"}}
{"id": 5, "command": "continue"}

Receive Responses and Events

{"event": "ready", "data": {}}
{"id": 1, "result": {"breakpoints": [{"id": 1, "file": "Cart.js", "line": 42, "script_path": "/app_storefront/cartridge/controllers/Cart.js"}]}}
{"event": "thread_stopped", "data": {"thread_id": 5, "location": {"file": "Cart.js", "line": 42, "function_name": "show"}}}

Available RPC Commands

| Command | Key Args | Description | | ------------------ | ------------------------------------------------ | ------------------------ | | set_breakpoints | breakpoints: [{file, line, condition?}] | Replace all breakpoints | | list_breakpoints | | List current breakpoints | | continue | thread_id? | Resume halted thread | | step_over | thread_id? | Step to next line | | step_into | thread_id? | Step into function | | step_out | thread_id? | Step out of function | | get_stack | thread_id? | Get call stack | | get_variables | thread_id?, frame_index?, scope?, object_path? | Get variables | | evaluate | expression, thread_id?, frame_index? | Evaluate expression | | list_threads | | List threads | | select_thread | thread_id | Switch thread | | select_frame | index | Switch frame |

DAP Mode (IDE Integration)

For VS Code and other DAP-compatible IDEs:

b2c debug

This starts a DAP debug adapter over stdio, used by IDE launch configurations.

Related Skills

b2c-cli:b2c-logs - Retrieve server logs for investigating errors found during debugging
b2c-cli:b2c-code - Deploy code changes before debugging
b2c-cli:b2c-config - Verify instance configuration and credentials

Agent Skills: B2C Debug Skill

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