Suparch

Search supplements by what's inside.

Suparch is an open-source MCP server for searching, comparing, and calculating structured supplement facts. It provides label data and deterministic calculations; it does not diagnose conditions or recommend supplements.

Current tools

• search_products: search by product text, included ingredients, excluded ingredients, ingredient forms, product type, target group, brand, and price.

• get_product: return the complete normalized label record for a product.

• compare_products: compare per-serving ingredients and forms.

• calculate_stack: add known label amounts for user-supplied daily servings.

• get_catalog_info: report snapshot schema, size, timestamps, and product count.

Production deployments use an immutable SQLite snapshot opened in read-only mode. The crawler and catalog builder run separately from the public MCP process, which makes the server suitable for ephemeral MCP Hub containers.

Related MCP server: mcp-server-npm

English affiliate-feed MVP

The MVP accepts an approved iHerb affiliate catalog as UTF-8 CSV or CSV.GZ. It deliberately keeps one market contract: English (en-US), USD prices, and HTTPS iherb.com product URLs. Rows outside an English supplement category or with another currency are excluded.

uv run suparch-catalog import-iherb-feed \
  --input build/iherb-us-feed.csv.gz \
  --report build/iherb-import-report.json \
  --min-products 1 \
  --min-gtin-coverage 0 \
  --output build/iherb-products.jsonl

--min-products and --min-gtin-coverage are atomic publication gates. Set them after inspecting the first approved feed rather than guessing production thresholds. A failed gate preserves the previous product output and writes a non-product report containing counts and coverage ratios.

The importer recognizes common Impact and retail-feed column names for product name, brand/manufacturer, URL, current price, currency, GTIN/UPC, and category. It derives the canonical iHerb product ID from the /pr/ URL, validates GTIN check digits, removes duplicate products, and reports every skipped row class. Use repeated --category options when an approved feed uses additional English category names:

uv run suparch-catalog import-iherb-feed \
  --input build/iherb-us-feed.csv.gz \
  --category supplement \
  --category "sports nutrition" \
  --output build/iherb-products.jsonl

Affiliate catalogs usually provide offers rather than complete Supplement Facts. Run the DSLD enrichment step below before relying on ingredient search, comparison, or stack calculation. A direct --database build is useful for offer/name search but can contain products without label rows.

Optional NIH DSLD label enrichment

Suparch's product catalog is intended to contain iHerb products. NIH's Dietary Supplement Label Database (DSLD) is an optional label source for enrichment when an iHerb record can be matched by UPC. DSLD records must not be presented as if they were products sold by iHerb.

Sync a resumable DSLD JSONL enrichment source:

uv run suparch-catalog dsld-sync \
  --query magnesium \
  --status on-market \
  --limit 1000 \
  --output build/dsld-products.jsonl

Then enrich an authorized iHerb Product JSON/JSONL source by matching UPCs:

uv run suparch-catalog enrich-dsld \
  --iherb build/iherb-products.jsonl \
  --dsld build/dsld-products.jsonl \
  --output build/enriched-iherb-products.jsonl \
  --report build/dsld-enrichment-report.json \
  --min-label-coverage 0 \
  --require-label \
  --database build/catalog.sqlite

Enrichment also fails atomically when it produces no products or misses the operator-selected --min-label-coverage. The report separates UPC matches from products that actually contain ingredient rows.

Use --limit 0 for the complete matching result set. The sync uses bounded concurrency and retries, flushes each page to disk, resumes by DSLD label ID, and repairs a truncated final JSONL record after an interrupted write. A sync sidecar pins the query, market status, limit, API, and parser version so incompatible runs cannot be mixed. Resume is only for interrupted runs; use --no-resume to refresh a completed snapshot and reconcile changed labels.

Quick start

uv sync --extra dev
uv run suparch

Suparch uses the bundled sample catalog by default. To use another catalog:

uv run suparch-catalog build \
  --input src/suparch/data/sample_catalog.json \
  --output catalog.sqlite

SUPARCH_DB_PATH=./catalog.sqlite uv run suparch

Run the MCP development inspector:

uv run mcp dev src/suparch/server.py

Run checks:

uv run pytest
uv run ruff check .

Build and verify a catalog

uv run suparch-catalog build \
  --input products.json \
  --output catalog.sqlite

uv run suparch-catalog verify \
  --database catalog.sqlite

The builder writes to a temporary file, runs SQLite integrity checks, and publishes the final database with an atomic rename. It also creates:

catalog.sqlite.sha256
catalog.sqlite.manifest.json

Inputs may be a JSON object, JSON array, or JSONL file. Repeat --input to merge multiple normalized files into one snapshot.

Parse a saved iHerb product page

uv run suparch-catalog parse-html \
  --input product.html \
  --url https://www.iherb.com/pr/example-product/12345 \
  --output product.json

Discover product references from iHerb's published sitemap without using its disallowed search path:

uv run suparch-catalog iherb-discover \
  --limit 1000 \
  --output build/iherb-product-refs.jsonl

The sitemap contains multiple iHerb departments, so these references are only discovery input. An authorized feed or page-ingestion job must filter the supplement category before publishing a Suparch catalog.

To merge the parsed product directly into a catalog snapshot:

uv run suparch-catalog parse-html \
  --input product.html \
  --url https://www.iherb.com/pr/example-product/12345 \
  --database catalog.sqlite

For batch ingestion, use a manifest so the catalog is loaded and published only once:

[
  {
    "input": "pages/product-12345.html",
    "url": "https://www.iherb.com/pr/example-product/12345",
    "locale": "en-US"
  }
]

uv run suparch-catalog parse-manifest \
  --manifest crawl-manifest.json \
  --database catalog.sqlite

Single-page live fetching exists for development but is disabled unless the operator explicitly passes --allow-live-fetch. It checks the current robots.txt, rate limits requests, and does not implement authentication, anti-bot bypass, or browser fingerprint evasion. Operators remain responsible for reviewing the site's current terms before using it.

At the time of the latest project check, standard product paths were allowed by the published robots rules, but unauthenticated product requests returned HTTP 403. Suparch preserves that fail-closed behavior. See docs/data-sources.md for approved-input options and the official affiliate path.

Hub deployment

Hub deployments require an authorized iHerb-backed catalog. Suparch does not ship NIH records as a substitute for iHerb inventory, pricing, or availability.

Run the stateless Streamable HTTP transport:

SUPARCH_TRANSPORT=streamable-http \
SUPARCH_HOST=0.0.0.0 \
PORT=8000 \
SUPARCH_DB_PATH=/data/catalog.sqlite \
uv run suparch

If the Hub cannot mount persistent files, publish the catalog to versioned object storage:

SUPARCH_CATALOG_URL=https://cdn.example.com/catalog-2026-07-16.sqlite \
SUPARCH_CATALOG_SHA256=<sha256> \
SUPARCH_TRANSPORT=streamable-http \
uv run suparch

Suparch downloads and validates the artifact during startup, then opens it read-only. The MCP endpoint defaults to /mcp.

Build the container:

docker build -t suparch .
docker run --rm -p 8000:8000 \
  -e SUPARCH_CATALOG_URL=https://cdn.example.com/catalog.sqlite \
  -e SUPARCH_CATALOG_SHA256=<sha256> \
  suparch

If SUPARCH_CATALOG_SHA256 is omitted for a custom URL, Suparch derives the manifest URL by appending .manifest.json. Set SUPARCH_CATALOG_MANIFEST_URL only when the manifest lives elsewhere.

MCP Registry

The repository includes an official Registry-compatible server.json for the OCI package ghcr.io/namjeongwan/suparch. Version tags such as v0.1.0 publish the corresponding image through GitHub Actions. Registry publication should only run after that exact image tag is publicly available.

JSON catalog format

[
  {
    "id": "source:product-id",
    "source": "example",
    "source_product_id": "product-id",
    "name": "Magnesium Glycinate",
    "brand": "Example Labs",
    "serving_size": "2 capsules",
    "servings_per_container": 60,
    "active_ingredients": [
      {
        "canonical_name": "magnesium",
        "label_name": "Magnesium",
        "form": "magnesium glycinate",
        "amount": "200",
        "unit": "mg",
        "normalized_amount": "200000",
        "normalized_unit": "mcg",
        "daily_value_percent": "48"
      }
    ],
    "other_ingredients": ["hypromellose"],
    "price": {
      "amount": "19.99",
      "currency": "USD"
    },
    "product_url": "https://example.com/products/product-id",
    "crawled_at": "2026-07-16T00:00:00Z"
  }
]

All label strings are preserved alongside normalized values. Normalization must never destroy the source label text.

DSLD quantity and daily-value operators are preserved. Non-equality amounts such as < 1 g remain visible in label details but are excluded from stack arithmetic because they are not exact values. When a label provides different daily values for adults, children, pregnancy, or lactation, every target-group entry is returned instead of presenting the first percentage as universal.

Search results return compact summaries with at most 20 canonical ingredient names plus the total ingredient count. Use get_product for the complete label.

Architecture

authorized iHerb feed/API --------------> iHerb Product JSONL
authorized saved HTML -> parser --------> iHerb Product JSONL
                                                   |
                                optional DSLD enrichment by UPC
                                                   |
                                                   v
                                         immutable SQLite snapshot
                                                   |
MCP client -> stateless Suparch server -> read-only repository

The MCP layer only retrieves and calculates product facts. Domain-specific skills or clients remain responsible for interpreting symptoms, selecting nutrient targets, and presenting medical guidance.

See docs/architecture.md for the deployment and data publication design.

Environment variables

iHerb data acquisition

iHerb's current robots policy disallows automated /search URLs and advertises product sitemaps. Standard product pages are not disallowed by path, but unauthenticated crawler requests currently receive HTTP 403. Suparch does not evade that access control.

The production path is:

approved iHerb affiliate feed/API or operator-supplied pages
  -> iHerb Product records
  -> optional DSLD enrichment by UPC
  -> immutable SQLite snapshot
  -> read-only MCP

iHerb lists Partnerize, Impact, CJ, and Awin as official affiliate platforms and explicitly accepts shopping-comparison partners. An approved feed or written data-access permission is therefore the next external dependency. See docs/affiliate-onboarding.md for the exact application text, requested feed fields, licensing questions, and safe handoff.