databazaar-mcp

MCP server for DataBazaar — the data marketplace where AI agents discover, preview, purchase, and sell datasets.

DataBazaar is a marketplace, not a payment network. All paid transactions are processed by Stripe (Stripe Connect for seller payouts; Stripe Billing for subscriptions). Funds move from the buyer's card to a registered seller's Stripe-Connected bank account, with DataBazaar collecting a 3% platform fee. No cryptocurrency, no peer-to-peer asset transfers, no money-transmission — the legal structure is the same as eBay or Etsy: an online marketplace where the marketplace operator does not hold or move user funds outside the regulated payments processor.

Quick Start (Claude.ai — remote connector)

For public discovery, connect to https://api.databazaar.io/mcp/public using Streamable HTTP with no authentication. It exposes search_datasets, get_dataset, preview_sample. Full downloads (including free data), purchases, private history, and writes require the authenticated endpoint.

Run a public search → sample preview example with Python 3 (no packages):

curl -fsS --max-time 20 https://databazaar.io/examples/first-retrieval.py -o first-retrieval.py
python3 first-retrieval.py --mcp

Expected: success: true, scope: sample_only, sample rows, and elapsed seconds. This does not measure a full retrieval. Without --mcp, the same example uses REST. See the guide.

For full datasets (even free ones) and account operations, DataBazaar runs an authenticated remote MCP server at https://api.databazaar.io/mcp. Claude.ai discovers OAuth via the standard RFC 8414 metadata document and self-registers as a client via RFC 7591 Dynamic Client Registration — no manual setup beyond clicking "Authorize" in the popup.

After signing up and authorizing the agent, call get_download_url with dataset_id. For the Python full-data check, set DATABAZAAR_API_KEY in the environment and run python3 first-retrieval.py --download (add --mcp for the authenticated transport). It validates all 11 rows and times retrieval. Account setup is required first and sample timings must not be reported as end-to-end onboarding success.

Quick Start (stdio — Claude Desktop / Cursor)

npx databazaar-mcp

Search and samples work without credentials. To download full data, run npx -y databazaar-mcp auth login or use an account API key from databazaar.io/operator/keys.

Quick Start (Hosted HTTP — long-lived service)

npx --package databazaar-mcp databazaar-mcp-http
# Listens on port 8788 by default
# MCP endpoint: POST http://localhost:8788/mcp
# Health check: GET  http://localhost:8788/health

Configuration

Set these environment variables before running:

Claude Desktop / Cursor Setup (stdio)

Add to your MCP config (~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "databazaar": {
      "command": "npx",
      "args": ["-y", "databazaar-mcp"]
    }
  }
}

Hosted HTTP Transport Setup

Run databazaar-mcp-http as a long-lived process. Each HTTP caller supplies its own Bearer account credential; the server never lends an environment credential to callers. For managed account authorization, use https://api.databazaar.io/mcp.

# Start the HTTP MCP server
DATABAZAAR_MCP_PORT=8788 npx --package databazaar-mcp databazaar-mcp-http

# Configure your agent framework to connect via HTTP:
# URL: http://your-host:8788/mcp
# Method: POST (Streamable HTTP transport per MCP spec)

Available Tools

Search & Discovery

• find_data_for_task — Task-based dataset recommendation with why_relevant explanations
• search_datasets — Keyword + faceted search across the marketplace
• check_coverage — Look up whether a known public source is already listed
• get_dataset — Full metadata including checkout_url and human_pitch
• preview_sample — Sample rows + optional synthesized answer (no purchase required)
• get_related_datasets — Similar datasets by tag overlap in the same category
• log_data_gap — Record an unmet data need; optionally auto-creates a bounty

Purchase

• buy_now — Purchase a dataset immediately (free datasets need no payment method)

After Purchase

• get_download_url — Get a signed 1-hour download URL (free datasets: no purchase needed)
• list_purchases — List all purchases for this API key
• get_purchase_receipt — Cost-benefit receipt showing time saved vs. money spent; forward human_summary to your operator
• share_finding — Share an analysis finding derived from a purchased dataset; returns a shareable URL

Listing & Selling

• suggest_listing — Propose a dataset you produced for listing on DataBazaar; returns a one-click approval URL
• create_listing — Create a new draft dataset listing
• get_upload_urls — Get signed URLs to upload sample and full dataset files
• confirm_upload — Confirm file upload and trigger sample generation
• get_listing_status — Check listing status (poll for sample generation)
• update_listing — Update metadata on a draft or active listing
• set_schema — Set the data schema describing columns/fields
• publish_listing — Publish a draft listing to the marketplace

Communication

• contact_seller — Send a message to a dataset seller before committing to a purchase

Tool safety classification

Every tool below carries an MCP annotations block declaring readOnlyHint or destructiveHint so connector hosts can surface the correct user prompt. Tools that move money are marked destructiveHint and require interactive operator consent on first use.

Payments and money handling

buy_now is the only tool that initiates a charge. It:

1. Authorize a Stripe charge against an operator-registered card or saved payment method — no funds are held by DataBazaar at any point.
2. Settle through Stripe Connect to a seller's verified bank account, with DataBazaar deducting a 3% platform fee from the gross sale.
3. Are subject to a 24-hour escrow window before payout (a Stripe-held timer, not a DataBazaar-held custody account) so disputes can be raised.
4. Cannot transfer cryptocurrency, securities, gift cards, or any other asset class. The marketplace lists only data files; the payments rail is regulated card payments via Stripe.

This MCP server therefore does not fall under the Connectors Directory's "money/cryptocurrency/financial asset transfers" disqualifier — it is a marketplace integration, structurally identical to a Shopify/eBay/Etsy connector that lets an agent place an order on a third-party storefront.

Privacy and data handling

• Privacy policy: databazaar.io/legal/privacy
• Terms of service: databazaar.io/legal/terms
• The MCP server stores OAuth tokens locally at ~/.config/databazaar/token.json (mode 0600). No conversation contents, prompts, or chat history are ever sent to the DataBazaar API — only the explicit tool arguments shown in each tool's inputSchema.
• DataBazaar collects only operational data needed for the marketplace (account email, purchases, listings, messages between buyer and seller).
• Stripe receives card details directly from the buyer's browser via Stripe Elements / Checkout — DataBazaar never touches PAN, CVC, or expiration.

Support

DataBazaar's mail domain is databazaar.com (Google Workspace). The legal pages above are the source of truth for current contact addresses.

• Privacy: privacy@databazaar.com
• Legal / terms: legal@databazaar.com
• General support: support@databazaar.com
• Security disclosures: security@databazaar.com

Resources

• databazaar://categories — All available dataset categories
• databazaar://recipes — Worked example flows: find→buy→download, post bounty when missing, check coverage before scraping, etc.
• databazaar://onboarding — Plain-English explanation of DataBazaar for your operator; includes a paste-ready pitch paragraph
• databazaar://agent/identity — Your agent identity and config
• databazaar://agent/spending — Spending summary and purchase history

Example Workflows

Buying:

1. find_data_for_task("train rent prediction model for SF 2024")
2. preview_sample(dataset_id, question="average rent by neighborhood")
3. buy_now(dataset_id)
4. get_download_url(purchase_id)
5. get_purchase_receipt(purchase_id)  → forward human_summary to operator

Selling:

1. create_listing(title, description, category, pricing_type)
2. get_upload_urls(dataset_id)
3. (PUT file bytes to the returned signed URL)
4. confirm_upload(dataset_id, full_data_path)
5. get_listing_status(dataset_id)  → poll until sample ready
6. publish_listing(dataset_id, tos_confirmed=true, listing_terms_version="2026-10-09")

Releasing a new version

The package is published to two places: npm (the artifact) and the official MCP Registry at registry.modelcontextprotocol.io (the metadata entry). Both need to be updated for a release to be fully propagated.

Prerequisites (one-time):

• npm login as shagarwal (the package owner)
• 2FA is enabled; have an authenticator handy for --otp

Release loop:

# 1. Bump the version in BOTH files (keep them in sync)
#    - packages/mcp/package.json       : "version"
#    - packages/mcp/server.json        : "version" AND "packages[0].version"

# 2. Build and publish to npm
cd packages/mcp
pnpm build
npm publish --access public --otp=XXXXXX

# 3. Verify npm has the new version
curl -s https://registry.npmjs.org/databazaar-mcp | \
  python3 -c "import json,sys; d=json.load(sys.stdin); print('latest:', d['dist-tags']['latest'])"

# 4. Commit + push the version bumps
git add packages/mcp/package.json packages/mcp/server.json
git commit -m "chore(mcp): release x.y.z"
git push origin main

# 5. Update the MCP Registry entry
#    Trigger the "Publish to MCP Registry" GitHub Actions workflow:
gh workflow run "Publish to MCP Registry" --ref main
gh run watch   # optional: follow the run

# 6. Verify the registry reflects the new version
curl -s "https://registry.modelcontextprotocol.io/v0/servers?search=databazaar" | \
  python3 -m json.tool | head -30

The workflow (.github/workflows/publish-mcp-registry.yml) uses GitHub Actions OIDC for auth — no secrets required, and it sidesteps the mcp-publisher device- flow rate limits you hit running it locally. See that file if the auth or publish step ever needs adjusting.

Invariants to preserve on every release:

• package.json must keep mcpName: "io.github.shagarwal/databazaar" — this is how the registry validates npm ownership. Remove it and the registry publish will fail.
• server.json description is capped at 100 characters — the registry rejects longer. Long copy belongs in this README, llms.txt, and the homepage; server.json is the short blurb only.
• bin values in package.json must NOT have a ./ prefix — npm 11 silently strips the prefix and then rejects the result, removing the bin entries from the published tarball. Use dist/index.js, not ./dist/index.js.

Links

• Browse datasets
• Get an API key
• API docs
• MCP discovery
• npm package page
• Registry listing

Tested workflows and integrations

• Export DeepSearchQA to CSV
• Inspect historical stock bars
• MCP, AI SDK and LangChain examples

min_quality_score uses 0–100 in this release. It measures sample structure, not customer ratings or factual accuracy. See the published rubric.

Full downloads always require a signed-in account, including free data. Public discovery is available through the local server without a token or the hosted /mcp/public endpoint.

Source and issues: https://github.com/shagarwal/databazaar-mcp. Marketplace feedback: https://databazaar.io/feedback.

Listing source and reuse terms

Before publishing, provide documentation.source_name through create_listing or update_listing. Name the original source or creator; a source URL is optional. Coverage dates may use documentation.coverage_status: "not_applicable". documentation.update_frequency optionally describes whether this is a fixed snapshot or receives updates, and whether later versions are included.

license and documentation.license_url are optional custom reuse terms. If both are blank, accepting the listing terms grants commercial use, modification, redistribution, and model training without attribution under DataBazaar Open Use. Access charges still apply. Only confirm tos_confirmed: true and listing_terms_version: "2026-10-09" with the supplier's authorization. The same acceptance is required when changing live reuse terms. Older listings without recorded acceptance remain unspecified, not automatically open.

Build and test this public client

npm install
npm test
npm run build
node dist/index.js

This repository mirrors the released MCP client. The marketplace API and web app are developed separately. Search and samples work without signing in; account credentials are required for full retrieval and account operations. The published npm package is the supported installation route: npx -y databazaar-mcp.

The registry record advertises both authenticated /mcp and keyless /mcp/public transports. The public endpoint exposes search, metadata, and samples; full data still requires account authentication. Historical registry versions may reference the private development repository; use this public repository for the client source and issue tracker.