transcript

Documentation

Overview

Package transcript provides shared types and utilities for parsing JSONL transcripts. Used by agents that share the same JSONL format (Claude Code, Cursor).

Index

• Constants
• func ExtractUserContent(message json.RawMessage) string
• func SliceFromLine(content []byte, startLine int) []byte
• type AssistantMessage
• type ContentBlock
• type Line
  • func ParseFromBytes(content []byte) ([]Line, error)
  • func ParseFromFileAtLine(path string, startLine int) ([]Line, error)
• type ToolInput
• type UserMessage

Constants

const (
	TypeUser      = "user"
	TypeAssistant = "assistant"
)

Message type constants for transcript lines.

const (
	ContentTypeText    = "text"
	ContentTypeToolUse = "tool_use"
)

Content type constants for content blocks within messages.

Functions

func ExtractUserContent

func ExtractUserContent(message json.RawMessage) string

ExtractUserContent extracts user content from a raw message. Handles both string and array content formats. IDE-injected context tags (like <ide_opened_file>) are stripped from the result. Returns empty string if the message cannot be parsed or contains no text.

func SliceFromLine

func SliceFromLine(content []byte, startLine int) []byte

SliceFromLine returns the content starting from line number `startLine` (0-indexed). This is used to extract only the checkpoint-specific portion of a cumulative transcript. For example, if startLine is 2, lines 0 and 1 are skipped and the result starts at line 2. Returns empty slice if startLine exceeds the number of lines.

Types

type AssistantMessage

type AssistantMessage struct {
	Content []ContentBlock `json:"content"`
}

AssistantMessage represents an assistant message in the transcript.

type ContentBlock

type ContentBlock struct {
	Type  string          `json:"type"`
	Text  string          `json:"text,omitempty"`
	Name  string          `json:"name,omitempty"`
	Input json.RawMessage `json:"input,omitempty"`
}

ContentBlock represents a block within an assistant message.

type Line

type Line struct {
	Type    string          `json:"type"`
	Role    string          `json:"role,omitempty"`
	UUID    string          `json:"uuid"`
	Message json.RawMessage `json:"message"`
}

Line represents a single line in a Claude Code or Cursor JSONL transcript. Claude Code uses "type" to distinguish user/assistant messages. Cursor uses "role" for the same purpose.

func ParseFromBytes

func ParseFromBytes(content []byte) ([]Line, error)

ParseFromBytes parses transcript content from a byte slice. Uses bufio.Reader to handle arbitrarily long lines.

func ParseFromFileAtLine

func ParseFromFileAtLine(path string, startLine int) ([]Line, error)

ParseFromFileAtLine reads and parses a transcript file starting from a specific line. Uses bufio.Reader to handle arbitrarily long lines (no size limit). Returns:

• lines: parsed transcript lines from startLine onwards (malformed lines skipped)
• error: any error encountered during reading

The startLine parameter is 0-indexed (startLine=0 reads from the beginning). This is useful for incremental parsing when you've already processed some lines.

type ToolInput

type ToolInput struct {
	FilePath     string `json:"file_path,omitempty"`
	NotebookPath string `json:"notebook_path,omitempty"`
	Description  string `json:"description,omitempty"`
	Command      string `json:"command,omitempty"`
	Pattern      string `json:"pattern,omitempty"`
	// Skill tool fields
	Skill string `json:"skill,omitempty"`
	// WebFetch tool fields
	URL    string `json:"url,omitempty"`
	Prompt string `json:"prompt,omitempty"`
}

ToolInput represents the input to various tools. Used to extract file paths and descriptions from tool calls.

type UserMessage

type UserMessage struct {
	Content interface{} `json:"content"`
}

UserMessage represents a user message in the transcript.