MCP For Claude Marketplace
LLM JSON Repair Utility

LLM JSON Repair Utility MCP Connector for Claude

A+

Fixes malformed, truncated, or dirty JSON strings produced by LLMs.

3 tools Official Updated Oct 1, 2026 Official Vinkius Partner
More Details Connect to Claude

This MCP server provides deterministic, character-level repair for JSON strings that fail to meet RFC 8259 standards. It is designed to handle common LLM failures such as trailing commas, unquoted keys, single quotes, and structural truncation where braces or brackets are left unclosed. Using a state-machine approach, it ensures predictable results without hallucinating data. You can use repair_json_string to fix broken structures, validate_json_integrity to check for syntax violations, and extract_json_from_text to pull JSON out of conversational filler or markdown blocks.

jsonllmrepairparsingdata-integrity

3 tools expose this connector's capabilities to your AI agent.

extract_json_from_text

repair_json_string

validate_json_integrity

See how to talk to your AI agent using LLM JSON Repair Utility.

Fix this broken JSON: {"name": 'John', "age": 30,}

{"name": "John", "age": 30}

Extract the JSON from this text: Here is the data: ```json {"id": 123} ``` Hope this helps!

{"id": 123}

The LLM cut off here: {"items": [{"id": 1}, {"id": 2

{"items": [{"id": 1}, {"id": 2}]}

Unlike probabilistic LLMs, this server uses a deterministic state machine. This means it only fixes structural issues like missing brackets or trailing commas without inventing or changing the actual data content.

Related Connectors

Truncation Detector & Graceful Terminator

Truncation Detector & Graceful Terminator MCP

3 tools Official

Detects and repairs truncated LLM outputs to restore structural integrity.

A+ View details →
Output Format Stability Checker

Output Format Stability Checker MCP

3 tools Official

Detect non-deterministic shifts in LLM response structures.

A+ View details →
CSV <-> JSON Converter

CSV <-> JSON Converter MCP

2 tools Official

Flawless data translation. Convert massive CSV files to JSON and back instantly without LLM hallucination or dropped quotes.

A+ View details →
Markdown Lint Analyzer

Markdown Lint Analyzer MCP

4 tools Official

Automated structural and formatting validation for Markdown documents.

A+ View details →