
A structured data reader and writer like 'jq' and 'yq' for AI Agents
概览
A token-efficient, schema-aware MCP server for safely reading and modifying JSON, YAML, and TOML files Getting Started • CLI Usage • Available Tools • Development Stop AI coding tools from breaking your data files. No more grep guesswork, hallucinated fields, or non-schema-compliant data added to files. This MCP server gives AI assistants a strict, round-trip safe interface for working with structured data. AI coding tools often destroy structured data files: - They through huge json, yaml, and toml files (like json logs, or AI transcript files) and guess at keys. - They fields that never existed. - They use that leave files in invalid states. - They break and . - They can't changes before writing. provides AI assistants with proper tools for structured data: - : Extract exactly what you need without loading entire files. - : Enforce correctness using SchemaStore.org or custom schemas. - : ; preserve comments and formatting. - : JSON, YAML, and TOML through a unified interface.
README
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mcp-json-yaml-toml
A token-efficient, schema-aware MCP server for safely reading and modifying JSON, YAML, and TOML files
Getting Started • CLI Usage • Available Tools • Development
Stop AI coding tools from breaking your data files. No more grep guesswork, hallucinated fields, or non-schema-compliant data added to files. This MCP server gives AI assistants a strict, round-trip safe interface for working with structured data.
The Problem
AI coding tools often destroy structured data files:
- They grep through huge json, yaml, and toml files (like json logs, or AI transcript files) and guess at keys.
- They hallucinate fields that never existed.
- They use sed and regex that leave files in invalid states.
- They break YAML indentation and TOML syntax.
- They can’t validate changes before writing.
The Solution
mcp-json-yaml-toml provides AI assistants with proper tools for structured data:
- Token-efficient: Extract exactly what you need without loading entire files.
- Schema validation: Enforce correctness using SchemaStore.org or custom schemas.
- Safe modifications: Enforced validation on write; preserve comments and formatting.
- Multi-format: JSON, YAML, and TOML through a unified interface.
- Directive-based detection: Support for
# yaml-language-server,#:schema, and$schemakeys in all formats. - Constraint-based guided generation: Native LMQL support for proactive validation of partial inputs.
- Local-First: All processing happens locally. No data ever leaves your machine.
- Transparent JIT Assets: The server auto-downloads
yqif missing and fetches missing schemas from SchemaStore.org for local caching.
[!NOTE]
JSONC Support: Files with
.jsoncextension (JSON with Comments) are fully supported for reading, querying, and schema validation. However, write operations will strip comments due to library limitations.
Getting Started
Prerequisites
- Python ≥ 3.11 installed.
安装
uvx mcp-json-yaml-toml配置
{
"mcpServers": {
"json-yaml-toml": {
"command": "uvx",
"args": ["mcp-json-yaml-toml"]
}
}
}