JSON Mapping & Context MCP Servers
This repo hosts two small MCP servers that showcase schema-aware JSON exploration and live data retrieval:
- JSON Mapping Finder (
json_mapping_server.py): Upload any JSON sample, flatten its schema, and use heuristic search (token overlap + fuzzy matching) to find paths for target field names. Great for accelerating ETL/API onboarding.
It is intentionally lightweight and fully HTTP-based for easy inspection with the MCP Inspector or Copilot Chat.
Highlights
- Schema-aware parsing: Flattens nested JSON, captures types/examples, and tracks depth.
- Heuristic mapping: Token overlap, substring checks, and fuzzy matching to suggest likely field paths.
- Plug-and-play MCP: Uses
StreamableHTTPSessionManagerfor modern MCP HTTP transport. - Portable: Pure Python, no external services beyond Open-Meteo.
Quick Start
Prereqs: Python 3.12+ and a virtual environment (.venv recommended).
python -m venv .venv
source .venv/bin/activate
pip install -r <(python - <<'PY'
import tomllib, sys
deps = tomllib.load(open("pyproject.toml","rb"))["project"]["dependencies"]
print("\n".join(deps))
PY)
Run the JSON Mapping Finder (port 3004)
.venv/bin/python json_mapping_server.py
Then inspect with:
npx -y @modelcontextprotocol/inspector http://localhost:3004
Exposed tools:
upload_json_sample(json_data): load a JSON sample (e.g.,sample_json.json) and build the schema index.list_schema(limit=200): view flattened paths with type + example values.search_fields(query, top_k=10): find likely paths for a single query.map_targets(targets, top_k=5): bulk mapping suggestions for multiple field names.clear_samples(): reset the index.
Sample Data
sample_json.json: a non-medical, nested sample for testing the JSON Mapping Finder.
Configuration
If you want to wire these into Copilot Chat, add entries like:
{
"mcpServers": {
"json-mapping": { "url": "http://localhost:3004" }
}
}
How it works (JSON Mapping Finder)
- Indexing: Walks objects/arrays, records paths (
$.foo.bar[*]), types, example values, and depth. - Scoring: Combines exact/substring boosts, Jaccard token overlap, and fuzzy ratio; lightly penalizes deep paths.
- Suggestions: Returns top matches with scores so you can review/accept quickly.
Notes
- No API keys required.
- All code is ASCII-only and dependency-light.