lv-inspect

name	lv-inspect
description	Inspect LiveView state (assigns, components) via Phoenix.LiveView.Debug in project_eval
argument-hint	[pid_tuple | 'list' | 'assigns' | 'assign:key' | 'components' | 'summary']

LiveView State Inspector

Inspect runtime state of LiveView processes using Phoenix.LiveView.Debug (Phoenix core) via project_eval. No LiveDebugger dependency needed — these are built into Phoenix LiveView.

Getting the PID

The current page's LiveView PID is in the <framework-details> context block. Example: Main LiveView #phx-GKR3k4n7RrVOhbBh with PID #PID<0.1378068.0>

Extract the three numbers → pid(0, 1378068, 0) in project_eval.

PID changes on page reload/reconnect — always use the PID from current context.

Commands

/lv-inspect list — All active LiveViews

Phoenix.LiveView.Debug.list_liveviews()
|> Enum.map(fn lv -> %{pid: lv.pid, view: lv.view, topic: lv.topic} end)

/lv-inspect assigns — Assign key list

{:ok, socket} = Phoenix.LiveView.Debug.socket(pid(0, PID2, 0))
keys = socket.assigns |> Map.keys() |> Enum.sort()
{length(keys), keys}

/lv-inspect assign:KEY — Specific assign value

{:ok, socket} = Phoenix.LiveView.Debug.socket(pid(0, PID2, 0))
Map.get(socket.assigns, :KEY)

/lv-inspect assign:KEY1,KEY2 — Multiple assigns

{:ok, socket} = Phoenix.LiveView.Debug.socket(pid(0, PID2, 0))
Map.take(socket.assigns, [:KEY1, :KEY2])

/lv-inspect components — LiveComponents in page

{:ok, components} = Phoenix.LiveView.Debug.live_components(pid(0, PID2, 0))
Enum.map(components, fn c -> %{cid: c.cid, module: c.module, id: c.id} end)

/lv-inspect summary — Assigns overview (types + sizes, avoids context pollution)

{:ok, socket} = Phoenix.LiveView.Debug.socket(pid(0, PID2, 0))

socket.assigns
|> Map.drop([:__changed__, :flash])
|> Enum.map(fn {k, v} ->
  summary = cond do
    is_list(v) -> {:list, length(v)}
    is_map(v) and Map.has_key?(v, :__struct__) -> {:struct, v.__struct__}
    is_map(v) -> {:map, map_size(v)}
    is_binary(v) and byte_size(v) > 100 -> {:string, byte_size(v)}
    is_pid(v) -> {:pid, inspect(v)}
    true -> v
  end
  {k, summary}
end)
|> Enum.sort_by(&elem(&1, 0))

Execution Workflow

1. Read PID from <framework-details> context
2. Substitute pid(0, PID2, 0) with actual values
3. Run via project_eval
4. Filter large values — if an assign is too large for context:
   • Lists: {:list, length(list)}
   • Maps >10 keys: {:map, Map.keys(map)}
   • Structs: {:struct, mod, Map.keys(Map.from_struct(s))}

API Reference

All functions are from Phoenix.LiveView.Debug (Phoenix core, always available):

Function	Returns
list_liveviews()	[%{pid, view, topic, transport_pid}]
socket(pid)	{:ok, %Phoenix.LiveView.Socket{}} or {:error, term}
live_components(pid)	{:ok, [%{id, cid, module, assigns, private, children_cids}]}
liveview_process?(pid)	boolean

For lower-level OTP inspection (rarely needed):

:sys.get_state(pid)              # Raw GenServer state
:erlang.process_info(pid)        # Memory, message queue, stack
Process.info(pid, :messages)     # Pending messages

Notes

• socket/1 reads state directly from the LiveView process (real-time, most reliable)
• PID lifecycle: LiveView PIDs change on page reload/reconnect — always use current context PID
• project_eval spawns an ephemeral process — PubSub subscriptions won't persist, but direct process queries work fine
• For before/after comparison: read assigns, trigger action via browser_eval, read assigns again