Blocksize Capital Agentic Payments

Institutional-grade market data for AI agents, with three integration surfaces:

• Public remote MCP discovery server: free symbol discovery, pricing inspection, and document search
• Paid HTTP API: live market data protected by direct x402 settlement
• Authenticated Claude, Cursor, and OpenAI MCP connectors: read-only market data with a free starter allowance of 15,000 live-data credits every month, then subscriptions from EUR 49/month

Public URLs

• Main Blocksize website: https://blocksize.info/?utm_source=agentic-widget&utm_medium=ai
• Homepage: https://mcp.blocksize.info/
• Remote MCP URL: https://mcp.blocksize.info/mcp/server/
• Anthropic-safe MCP URL: https://mcp.blocksize.info/anthropic/mcp/
• Claude connector docs: https://mcp.blocksize.info/claude-connector
• MCP manifest: https://mcp.blocksize.info/mcp/manifest.json
• OpenAPI JSON: https://mcp.blocksize.info/openapi.json
• Swagger UI: https://mcp.blocksize.info/docs
• Quickstart: https://mcp.blocksize.info/quickstart/remote-mcp
• First live price quickstart: https://mcp.blocksize.info/quickstart/first-price
• Prompt examples: https://mcp.blocksize.info/prompt-examples
• Privacy policy: https://mcp.blocksize.info/privacy
• Support: https://mcp.blocksize.info/support
• MCP Registry metadata: https://mcp.blocksize.info/server.json
• AI reader brief: https://mcp.blocksize.info/llms.txt
• Sitemap: https://mcp.blocksize.info/sitemap.xml
• Robots policy: https://mcp.blocksize.info/robots.txt
• Data package catalog: https://mcp.blocksize.info/data-packages.json
• Category hubs and claims boundary: https://mcp.blocksize.info/category-hubs.json
• RWA market data hub: https://mcp.blocksize.info/rwa-market-data
• Market data licensing hub: https://mcp.blocksize.info/market-data-licensing
• Signed oracle feeds hub: https://mcp.blocksize.info/signed-oracle-feeds

Agent and Search Discoverability

Blocksize is optimized to be found for high-intent searches around real-time price data, market data APIs for AI agents, x402-paid data, and MCP market data discovery.

Canonical intent pages:

• RWA market data API: https://mcp.blocksize.info/rwa-market-data
• Market data licensing and redistribution: https://mcp.blocksize.info/market-data-licensing
• Signed market data and oracle feeds: https://mcp.blocksize.info/signed-oracle-feeds
• Market data API for AI agents: https://mcp.blocksize.info/market-data-api-for-ai-agents
• Real-time price data API: https://mcp.blocksize.info/real-time-price-data-api
• Crypto VWAP API: https://mcp.blocksize.info/crypto-vwap-api
• Bid/ask price data API: https://mcp.blocksize.info/bid-ask-price-api
• FX rates API: https://mcp.blocksize.info/fx-rates-api
• Metals price API: https://mcp.blocksize.info/metals-price-api
• x402 market data API: https://mcp.blocksize.info/x402-market-data-api
• MCP market data server: https://mcp.blocksize.info/mcp-market-data-server
• Accountless market data API: https://mcp.blocksize.info/accountless-market-data-api
• Price data API examples: https://mcp.blocksize.info/price-data-api-examples
• Market data API comparison: https://mcp.blocksize.info/market-data-api-comparison
• Crypto market data API alternatives: https://mcp.blocksize.info/crypto-market-data-api-alternatives
• Oracle data API for AI agents: https://mcp.blocksize.info/oracle-data-api-for-ai-agents

Recommended repository topics and listing keywords:

market-data, price-data, real-time-data, mcp, ai-agents, x402, crypto-vwap, bid-ask, fx-rates, metals-api, agentic-payments

Indexing checklist:

• Submit https://mcp.blocksize.info/sitemap.xml in Google Search Console and Bing Webmaster Tools.
• Request indexing for the homepage, data package catalog, and every canonical intent page above.
• Use the MCP manifest, server.json, llms.txt, OpenAPI JSON, and data-packages.json as the canonical machine-readable citations in marketplaces, docs, and repo descriptions.
• Use category-hubs.json for dated coverage states, rights boundaries, methodology, and citation instructions. Cataloged, candidate, and production-promoted coverage are intentionally separate states.

RWA claims boundary:

• Blocksize already provides broad production coverage across its live market-data packages.
• Separately, the reconciled 2026-07-30 RWA research snapshot contains 1,169 RWA.xyz source-asset rows and 3,438 token-listing rows (3,435 unique contract identities). Its lossless cross-venue matrix contains 2,139 canonical assets and 5,161 venue instruments; these are catalog and identity grains, not production-feed counts.
• Candidate expansion lanes are not additional production feeds until their promotion gates pass.
• Zero newly sourced third-party or onchain additions have completed the full RWA expansion-workflow promotion process. This figure does not describe or reduce existing Blocksize production coverage.
• Hash-linked provenance receipts are not described as cryptographically signed unless a response includes a signature envelope with an algorithm, key identifier, digest, and signature.

Product Shape

1. Public remote MCP discovery server

The remote MCP server is meant for directory listings and fast evaluation in ChatGPT Developer Mode, Cursor, Claude MCP clients, Smithery, Glama, and other Streamable HTTP clients.

It exposes only read-only discovery tools:

• search_pairs
• list_instruments
• get_pricing_info
• get_product_catalog
• recommend_account_plan
• get_workflow_endpoint
• get_market_data_endpoint
• search
• fetch

This public surface does not execute paid live market data calls directly.

2. Paid HTTP market data API

The paid HTTP API is the production data path for live access:

• GET /v1/vwap/{pair}
• GET /v1/bidask/{pair}
• GET /v1/fx/{pair}
• GET /v1/metal/{ticker}
• GET /v1/batch

Free discovery endpoints:

• GET /v1/coverage
• GET /v1/search
• GET /v1/instruments/{service}
• GET /v1/samples/market-data?service=vwap&symbol=BTCUSD for a clearly synthetic value preview and attributed paid handoff
• GET /health

/v1/search is paginated with limit and offset. Its total_matches field is the full match count for the searched catalogs; the default 50 is only the response page size and is unrelated to starter credits.

Payment modes:

• signed x402 v2 payment per request via PAYMENT-SIGNATURE
• starter credit drawdown through an authenticated Claude, Cursor, or OpenAI connector principal

New eligible authenticated users receive 15,000 free live data credits every calendar month (UTC), positioned as Start with 15,000 free live-data credits every month. The allowance is an evaluation and prototyping licence with required attribution; production commercial use requires a subscription. The number is configured once in FREE_TIER_MONTHLY_CREDITS (src/config.py) and every surface renders it from there. Raw caller-selected HTTP identity headers are disabled in production and cannot claim or spend credits. When the monthly allowance is exhausted, agents can use direct x402 payment, start a subscription trial at /go/free-trial (plans from EUR 49/month, see /go/pricing), or contact Blocksize sales about an Enterprise authenticated account plan.

3. Anthropic-safe MCP beta

The Anthropic-safe MCP surface is mounted at /anthropic/mcp/ and exposes read-only tools only:

• search_pairs
• list_instruments
• get_credit_balance
• get_vwap
• get_bid_ask
• get_fx_rate
• get_metal_price

Live market data tools use server-side free-tier credits keyed to authenticated user identity. The allowance is 15,000 credits per verified identity per calendar month (UTC), set by FREE_TIER_MONTHLY_CREDITS and shared by the Claude, Cursor, and OpenAI connectors. The legacy ANTHROPIC_DAILY_CREDITS, CURSOR_DAILY_CREDITS, and OPENAI_DAILY_CREDITS variables are ignored; per-user entitlement overrides for subscribers still apply.

For local beta testing, set ANTHROPIC_ENABLE_BETA_TOKENS=true and ANTHROPIC_BETA_TOKENS to a JSON object mapping random bearer tokens to user ids. For public Claude custom connectors, set ANTHROPIC_AUTH_PROVIDER=clerk, keep ANTHROPIC_ENABLE_BETA_TOKENS=false, and configure the Clerk env vars in .env.example. The Claude OAuth metadata endpoints are served at /.well-known/oauth-protected-resource/anthropic/mcp/ and /.well-known/oauth-authorization-server/anthropic/mcp.

4. Advanced local MCP

For builders who want the full tool surface inside a local MCP client, this repo also contains the advanced local MCP server in src/mcp_server.py.

That mode is intended for direct builder integrations and requires local credentials.

Coverage

Use GET /v1/coverage for current source-backed counts and qualification boundaries. The response separates enabled live discovery namespaces, decision-grade canonical RWA identities, and research/manual-verification coverage. Namespace and venue-row counts overlap and must not be summed as a unique-instrument total.

Local Development

uv venv
source .venv/bin/activate
uv pip install -e ".[dev]"

Run the HTTP server:

uvicorn src.resource_server:app --port 8402

Run the advanced local MCP server:

python -m src.mcp_server

Tests

.venv/bin/python -m pytest tests/ -q

Listing Artifacts