agent-dbg

Original：🇺🇸 English

Translated

Debug Node.js/TypeScript/JavaScript applications using the agent-dbg CLI debugger. Use when: (1) investigating runtime bugs by stepping through code, (2) inspecting variable values at specific execution points, (3) setting breakpoints and conditional breakpoints, (4) evaluating expressions in a paused context, (5) hot-patching code without restarting, (6) debugging test failures by attaching to a running process, (7) any task where understanding runtime behavior requires a debugger. Triggers: "debug this", "set a breakpoint", "step through", "inspect variables", "why is this value wrong", "trace execution", "attach debugger", "runtime error".

1installs

Sourcetheodo-group/agent-dbg

Added on2026-02-10

NPX Install

npx skill4agent add theodo-group/agent-dbg agent-dbg

SKILL.md Content

View Translation Comparison →

agent-dbg Debugger

agent-dbg

is a CLI debugger for Node.js wrapping the V8 Inspector (CDP). It uses short

@refs

for all entities -- use them instead of long IDs.

Core Debug Loop

bash

# 1. Launch with breakpoint at first line
agent-dbg launch --brk node app.js

# 2. Set breakpoints at suspicious locations
agent-dbg break src/handler.ts:42
agent-dbg break src/utils.ts:15 --condition "count > 10"

# 3. Run to breakpoint
agent-dbg continue

# 4. Inspect state (shows location, source, locals, stack)
agent-dbg state

# 5. Drill into values
agent-dbg props @v1              # expand object
agent-dbg props @v1 --depth 3    # expand nested 3 levels
agent-dbg eval "items.filter(x => x.active)"

# 6. Fix and verify
agent-dbg set count 0            # change variable
agent-dbg hotpatch src/utils.js  # live-edit (reads file from disk)
agent-dbg continue               # verify fix

Debugging Strategies

Bug investigation -- narrow down with breakpoints

bash

agent-dbg launch --brk node app.js
agent-dbg break src/api.ts:50                    # suspect line
agent-dbg break src/api.ts:60 --condition "!user" # conditional
agent-dbg continue
agent-dbg vars                                    # check locals
agent-dbg eval "JSON.stringify(req.body)"         # inspect deeply
agent-dbg step over                               # advance one line
agent-dbg state                                   # see new state

Attach to running/test process

bash

# Start node with inspector
node --inspect app.js
# Or attach by PID
agent-dbg attach 12345
agent-dbg state

Trace execution flow with logpoints (no pause)

bash

agent-dbg logpoint src/auth.ts:20 "login attempt: ${username}"
agent-dbg logpoint src/auth.ts:45 "auth result: ${result}"
agent-dbg continue
agent-dbg console    # see logged output

Exception debugging

bash

agent-dbg catch uncaught          # pause on uncaught exceptions
agent-dbg continue                # runs until exception
agent-dbg state                   # see where it threw
agent-dbg eval "err.message"      # inspect the error
agent-dbg stack                   # full call stack

TypeScript source map support

agent-dbg automatically resolves

.ts

paths via source maps. Set breakpoints using

.ts

paths, see

.ts

source in output. Use

--generated

to see compiled

.js

if needed.

Ref System

Every output assigns short refs. Use them everywhere:

@v1..@vN

-- variables:

agent-dbg props @v1

,

agent-dbg set @v2 true

@f0..@fN

-- stack frames:

agent-dbg eval --frame @f1 "this"

BP#1..N

-- breakpoints:

agent-dbg break-rm BP#1

,

agent-dbg break-toggle BP#1

```
LP#1..N
```
-- logpoints:
```
agent-dbg break-rm LP#1
```

Refs

@v

/

@f

reset on each pause.

BP#

/

LP#

persist until removed.

Key Flags

```
--json
```
-- machine-readable JSON output on any command
```
--session NAME
```
-- target a specific session (default: "default")
```
--generated
```
-- bypass source maps, show compiled JS (on state/source/stack)

Command Reference

See references/commands.md for full command details and options.

Tips

```
agent-dbg state
```
after stepping always shows location + source + locals -- usually enough context
```
agent-dbg state -c
```
for source only,
```
-v
```
for vars only,
```
-s
```
for stack only -- save tokens
```
agent-dbg eval
```
supports
```
await
```
-- useful for async inspection
```
agent-dbg blackbox "node_modules/**"
```
-- skip stepping into dependencies
```
agent-dbg hotpatch file
```
reads the file from disk -- edit the file first, then hotpatch
Execution commands (
```
continue
```
,
```
step
```
,
```
pause
```
,
```
run-to
```
) auto-return status
```
agent-dbg stop
```
kills the debugged process and daemon

agent-dbg

NPX Install

Tags

SKILL.md Content

agent-dbg Debugger

Core Debug Loop

Debugging Strategies

Bug investigation -- narrow down with breakpoints

Attach to running/test process

Trace execution flow with logpoints (no pause)

Exception debugging

TypeScript source map support

Ref System

Key Flags

Command Reference

Tips