pi-session-logs

name	pi-session-logs
topic	Pi Session Logs
description	Query pi agent session logs as JSON Lines using Nushell pipelines. Use when debugging agent sessions, analyzing tool calls, or tracking file access in session history.
token_cost	250
keywords	["pi","session","log","debug","tool","agent"]
requires_tools	["nu"]

pi-session-logs

Query pi agent session logs stored as JSON Lines (.jsonl) files in ~/.pi/agent/sessions/<project-path>/. Each line is a JSON object representing a session event.

Define the Helper Function

def open-jsonl [file: path] {
    open $file --raw | lines | each { from json }
}

Entry Types

• session — metadata (version, id, timestamp, cwd)
• message — user or assistant messages with content and tool calls
• model_change — provider/model switches
• thinking_level_change — thinking level adjustments
• custom_message — hook output/errors, VCS notifications
• compaction — context summary when session was truncated

Loading & Filtering

# Load a single session
open-jsonl ~/.pi/agent/sessions/<project>/<session>.jsonl

# Load all sessions from a project
ls ~/.pi/agent/sessions/<project>/*.jsonl
| each { |f| open-jsonl $f.name } | flatten

Finding Tool Calls

Extract all tool calls from assistant messages:

# All tool calls with names and arguments
open-jsonl session.jsonl
| where type == "message" | where message.role == "assistant"
| get message.content | flatten
| where type == "toolCall" | select id name arguments

# Bash commands specifically
open-jsonl session.jsonl
| where type == "message" | where message.role == "assistant"
| get message.content | flatten
| where type == "toolCall" | where name == "bash"
| get arguments.command

# Files read
open-jsonl session.jsonl
| where type == "message" | where message.role == "assistant"
| get message.content | flatten
| where type == "toolCall" | where name == "read"
| get arguments.path

# Thinking content
open-jsonl session.jsonl
| where type == "message" | where message.role == "assistant"
| get message.content | flatten
| where type == "thinking" | get thinking

Hook Errors & VCS Notifications

# All hook errors (eslint, typecheck failures)
open-jsonl session.jsonl | where type == "custom_message" | where customType == "hook-error"
| select timestamp content

# VCS notifications (jj squashes)
open-jsonl session.jsonl | where type == "custom_message"
| where customType | str starts-with "Squashed"
| select customType content timestamp

Session Statistics

# Count events by type
open-jsonl session.jsonl | get type | uniq --count

# Count tool calls by type
open-jsonl session.jsonl
| where type == "message" | where message.role == "assistant"
| get message.content | flatten | where type == "toolCall"
| get name | uniq --count

# Token usage
open-jsonl session.jsonl
| where type == "message" | where message.role == "assistant"
| get message.usage | flatten | math sum

Custom Helper Functions

def "session-stats" [file: path] {
    let data = (open-jsonl $file)
    {
        total_events: ($data | length),
        messages: ($data | where type == "message" | length),
        tool_calls: ($data | where type == "message" | where message.role == "assistant" | get message.content | flatten | where type == "toolCall" | length),
        hook_errors: ($data | where type == "custom_message" | where customType == "hook-error" | length)
    }
}

Constraints

• Session paths contain encoded directory paths with -- prefix/suffix
• Tool calls are embedded in assistant messages under message.content[] with type == "toolCall"
• Use flatten to extract nested arrays from message.content
• Timestamps are ISO 8601 strings or Unix milliseconds