Module json_parser 

JSON Stream Parsing Module

Functions for parsing NDJSON (newline-delimited JSON) streams from Claude, Codex, Gemini, and OpenCode CLI tools.

NDJSON is a format where each line contains a complete JSON object. Agent CLIs emit NDJSON streams for real-time event processing.

This module uses serde for JSON parsing, which is ~100x faster than spawning jq for each event.

Key Types

• ClaudeParser - Parser for Claude CLI NDJSON output
• CodexParser - Parser for OpenAI Codex CLI NDJSON output
• GeminiParser - Parser for Google Gemini CLI NDJSON output
• OpenCodeParser - Parser for OpenCode CLI NDJSON output

Parser selection is controlled by crate::agents::JsonParserType.

Module Structure

• types - Shared types and event structures
• claude - Claude CLI output parser (with streaming support)
• codex - OpenAI Codex CLI output parser (with streaming support)
• gemini - Google Gemini CLI output parser (with streaming support)
• opencode - OpenCode CLI output parser (with streaming support)
• health - Parser health monitoring and graceful degradation
• printer - Test utilities for output verification (test-utils feature)

Streaming Support

All parsers now support delta streaming for real-time content display:

• Claude: Full streaming with DeltaAccumulator for text and thinking deltas
• Gemini: Streaming with delta flag support for message content
• Codex: Streaming for agent_message and reasoning item types
• OpenCode: Streaming for text events

In verbose mode, parsers show full accumulated content. In normal mode, they show real-time deltas for immediate feedback.

Verbosity Levels

The parsers respect the configured verbosity level:

• Quiet (0): Minimal output, aggressive truncation
• Normal (1): Balanced output with moderate truncation, shows real-time deltas
• Verbose (2): Default - shows more detail including tool inputs and full accumulated text
• Full (3): No truncation, show all content
• Debug (4): Maximum verbosity, includes raw JSON output

Internal Modules

The stream_classifier module is internal and handles automatic detection of streaming vs. non-streaming output. It is not exposed in the public API.

For detailed streaming contract documentation, see README.md in this directory.

Re-exports

pub use claude::ClaudeParser;

pub use codex::CodexParser;

pub use gemini::GeminiParser;

pub use opencode::OpenCodeParser;

pub use terminal::TerminalMode;

Modules

claude

Claude CLI JSON parser.

codex

Codex CLI JSON parser.

deduplication

Delta deduplication using KMP and Rolling Hash algorithms.

delta_display

Unified delta display system for streaming content.

gemini

Gemini CLI JSON parser.

health

Parser health monitoring and graceful degradation.

opencode

OpenCode event parser implementation

printer

Printer abstraction for testable output.

streaming_state

Unified streaming state tracking module.

terminal

Terminal mode detection for streaming output.

types

Shared types and utilities for NDJSON stream parsers.