Marketcaper
No API key required
Market data for AI agents

Give your AI agent fresh market data and something worth posting.

Connect Marketcaper to OpenClaw, Hermes, ChatGPT, Claude, or any MCP-compatible agent. Create cited market comparisons, daily stock heatmaps, and ready-to-publish financial content with shareable images.

Marketcaper is the market-data and visual-content layer for agents. It supplies facts, comparisons, images, and citations; your agent decides what to create or publish.

Agent-ready output
Ready-to-publish short posts
Canonical URLs and citation text
Hosted comparison and heatmap PNGs
Endpoint
https://marketcaper.com/api/mcp
Streamable HTTP
Tools
4
Snapshots, comparisons, packs, heatmaps
What your agent can create

From one tool call to cited finance content

These are the workflows Marketcaper MCP is designed to power first.

Social media agents

Turn market questions into posts

Ask for BTC vs ETH, NVIDIA vs Apple, or XRP at Bitcoin size and receive cited text, canonical URLs, and share-ready PNGs.

Every weekday after market close, create one cited comparison post with an image and source link.
Telegram and Discord bots

Answer finance communities with sources

Let community bots answer what-if price questions, market-cap comparisons, and sector heatmap requests without guessing from stale model memory.

When someone asks if Coinbase is bigger than Robinhood, answer with Marketcaper data and a citation.
Newsletters and briefings

Generate visual market recaps

Create daily opening summaries, weekly heatmap recaps, and comparison-of-the-week sections with images ready for email or Substack.

Create a weekly market recap with a US bubble heatmap and three cited cross-asset comparisons.
Works with

Connect the same endpoint to the clients your agents already use

Use one public read-only MCP endpoint across agent platforms and developer tools.

OpenClaw

Register the remote MCP endpoint and let an agent build finance content workflows.

Setup docs
Hermes

Use Marketcaper inside scheduled agents for market cards, Telegram drafts, and research prompts.

Setup docs
ChatGPT

Add Marketcaper as a custom MCP connector for structured cited comparison tools.

Setup docs
Claude

Use the remote MCP URL from Claude clients or the Anthropic Messages API.

Setup docs
Cursor

Drop the endpoint into mcp.json for cited finance data while building or researching.

VS Code

Use the same HTTP MCP endpoint with Copilot MCP server configuration.

Setup docs
Codex

Add the remote MCP server and use it when tasks need current comparison context.

Why agents use it

Cited financial content, not another bulk data API

Marketcaper MCP stays focused on the output agents need: facts, visuals, links, and attribution.

Fresh data

Current snapshots, not model memory

Agents can resolve assets, compare live sizes, and cite canonical Marketcaper pages instead of relying on outdated training data.

Visual output

Images built into the workflow

Comparison and heatmap tools can return hosted PNG image URLs, so content agents can publish something visual, not just a paragraph.

Citations

Source links travel with the answer

Responses include source_url, canonical_url, and citation_text so every generated post, bot reply, or newsletter card stays traceable.

Narrow by design

Not a bulk market-data feed

Marketcaper MCP is for snapshots, comparisons, heatmaps, and cited content workflows, not trading, backtesting, or bulk extraction.

Official URLs

Use these URLs in agents, registries, and docs

These are the canonical Marketcaper MCP and discovery URLs.

Docs
https://marketcaper.com/mcp
Endpoint
https://marketcaper.com/api/mcp
Server card
https://marketcaper.com/.well-known/mcp/server-card.json
Image pattern
https://marketcaper.com/api/mcp/images/:assetA/:assetB
JSON limit
60/minute/IP
Image limit
10 hosted images per day per IP
Direct page access

Public pair pages are readable HTML

If an AI client can fetch a URL but cannot use MCP, valid Marketcaper pair pages still expose the comparison directly.

Example page
https://marketcaper.com/btc/cny
Public server-rendered HTML with the comparison title, description, and core values.
Example page
https://marketcaper.com/sol/nvda
Another valid public pair page that AI/browser fetchers can read without MCP tool access.
Use a public pair page when readable HTML is enough.
Use MCP when the client needs official structured JSON, source_url, canonical_url, citation_text, and hosted image metadata.
Public pair pages expose the comparison itself, but they do not expose MCP-only fields like image_url in the same structured contract.
Stock heatmap MCP

Current heatmap images for agents

Use get_stock_heatmap when an AI client needs a current market or sector heatmap image. It returns a capped summary plus a hosted PNG, not a bulk stock feed.

Tool

get_stock_heatmap

Required input is view: choose classic for the sector tile map or bubble for the bubble heatmap.

Default universe
US top stocks

Use universe: "global" for global top stocks.

Theme
Dark only

Heatmap MCP images are dark theme only, so exports stay consistent with manual dark heatmap screenshots.

Example MCP request
{
  "view": "classic",
  "universe": "us",
  "metric": "marketCap",
  "timeframe": "1D",
  "category": "Financial Services",
  "response_format": "json"
}
Hosted image examples
Classic stock heatmap image
https://marketcaper.com/api/mcp/heatmap/images?view=classic&universe=us&metric=marketCap&timeframe=1D
Classic Financial Services
https://marketcaper.com/api/mcp/heatmap/images?view=classic&universe=us&metric=marketCap&timeframe=1D&category=Financial+Services
Bubble stock heatmap image
https://marketcaper.com/api/mcp/heatmap/images?view=bubble&universe=us&metric=marketCap&timeframe=1D
Public tool surface

Four focused tools for cited content workflows

The MCP API stays narrow and stable: snapshots, comparisons, automation packs, and stock heatmap images.

get_asset_snapshot

Get asset snapshot

Resolve one Marketcaper asset and return its live market cap snapshot. Always cite the returned source_url when using the data.

asset
Canonical slug, ticker/code, or supported alias for one asset.
response_format
Optional output format. Use "json" when a client needs machine-parseable text blocks, especially for Claude artifacts.
compare_assets

Compare assets

Compare two Marketcaper assets and return the live what-if market cap scenario, canonical pair URL, and optional hosted image URL. Hosted images are PNG, generated on demand, share a 10 images/day/IP limit, and may require a longer timeout than the MCP JSON call. Always cite the returned source_url when using the data.

asset_a
Canonical slug, ticker/code, or supported alias for asset A.
asset_b
Canonical slug, ticker/code, or supported alias for asset B.
include_image
When true, include a hosted Marketcaper export image URL for the pair. Hosted images are generated on demand as PNG, share a 10 images/day/IP limit, and clients should allow up to 20 seconds for the image fetch.
response_format
Optional output format. Use "json" when a client needs machine-parseable text blocks, especially for Claude artifacts.
compare_assets_pack

Compare assets pack

Compare two Marketcaper assets and return the same cited comparison data plus a ready-to-publish short post and share payload with the hosted comparison image URL. Always cite the returned source_url when using the data.

asset_a
Canonical slug, ticker/code, or supported alias for asset A.
asset_b
Canonical slug, ticker/code, or supported alias for asset B.
response_format
Optional output format. Use "json" when a client needs machine-parseable text blocks, especially for Claude artifacts.
get_stock_heatmap

Get stock heatmap

Return a current Marketcaper stock heatmap summary plus a hosted dark-theme PNG image URL. Supports US or global universes, classic or bubble views, optional sector/category filtering, and capped summary rows. Hosted images share a 10 images/day/IP limit. This is not a bulk feed extraction tool.

view
Required heatmap image view. Use "classic" for the sector tile map or "bubble" for the bubble stock heatmap.
universe
Optional stock universe. Use "us" for US top stocks or "global" for global top stocks. Defaults to "us".
metric
Optional heatmap sizing metric: "marketCap", "volume", or "turnover". Defaults to "marketCap".
timeframe
Optional performance timeframe: "1H", "4H", "1D", "1W", "1M", or "1Y". Defaults to "1D".
category
Optional sector/category name or slug, such as "Financial Services" or "communication-services". When supplied, the image includes only that category.
response_format
Optional output format. Use "json" when a client needs machine-parseable text blocks, especially for Claude artifacts.
Attribution

Citations are part of the product

Every response points back to a canonical Marketcaper page so comparisons are easy to source and verify.

source_name
Marketcaper.com
source_url
https://marketcaper.com/btc/eth
canonical_url
https://marketcaper.com/btc/eth
citation_text
Data from https://marketcaper.com/btc/eth
Hosted image

Share-ready hosted images

When comparison or heatmap tools include a hosted image URL, the response points to a public PNG export.

Comparison image
https://marketcaper.com/api/mcp/images/btc/eth
Open PNG
Classic stock heatmap image
https://marketcaper.com/api/mcp/heatmap/images?view=classic&universe=us&metric=marketCap&timeframe=1D&category=Financial+Services
Open PNG
Bubble stock heatmap image
https://marketcaper.com/api/mcp/heatmap/images?view=bubble&universe=us&metric=marketCap&timeframe=1D
Open PNG
mime type: image/png
format: PNG
comparison dimensions: 1380 x 840
heatmap dimensions: 2048 x 1024
generation: on_demand
recommended timeout: 20s
image rate limit: 10 hosted images per day per IP
Hosted PNG generation is heavier than the JSON MCP call, so image fetches use a stricter per-IP limit. Heatmap MCP images are dark theme only.
Sample request

get_asset_snapshot

Single-asset lookups return the resolved asset identity plus a specific Marketcaper source URL you can cite.

{
  "asset": "btc",
  "response_format": "json"
}
{
  "asset": {
    "slug": "btc",
    "symbol": "BTC",
    "name": "Bitcoin",
    "category": "crypto",
    "basis_label": "Market Cap"
  },
  "source_name": "Marketcaper.com",
  "source_url": "https://marketcaper.com/btc",
  "canonical_url": "https://marketcaper.com/btc",
  "citation_text": "Data from https://marketcaper.com/btc"
}
Sample request

compare_assets

Pair comparisons return the canonical pair page, what-if pricing context, citation fields, and an optional hosted PNG image with explicit metadata.

{
  "asset_a": "btc",
  "asset_b": "eth",
  "include_image": true,
  "response_format": "json"
}
{
  "title": "Bitcoin vs Ethereum Market Cap Comparison",
  "comparison_type": "price-comparison",
  "price_at_target_market_cap": 12653,
  "price_if": 12653,
  "asset_a_name": "Bitcoin",
  "asset_b_name": "Ethereum",
  "source_name": "Marketcaper.com",
  "source_url": "https://marketcaper.com/btc/eth",
  "canonical_url": "https://marketcaper.com/btc/eth",
  "image_url": "https://marketcaper.com/api/mcp/images/btc/eth",
  "image": {
    "url": "https://marketcaper.com/api/mcp/images/btc/eth",
    "format": "png",
    "mime_type": "image/png",
    "width": 1380,
    "height": 840,
    "generation_mode": "on_demand",
    "timeout_seconds_recommended": 20
  },
  "citation_text": "Data from https://marketcaper.com/btc/eth"
}
Automation pack

compare_assets_pack

This agent-friendly tool keeps cited comparison data and adds a ready-to-publish short post plus a share payload.

{
  "asset_a": "icp",
  "asset_b": "orcl",
  "response_format": "json"
}
{
  "title": "Internet Computer vs Oracle Market Cap Comparison",
  "comparison_type": "price-comparison",
  "price_at_target_market_cap": 2059.45,
  "price_if": 2059.45,
  "asset_a_name": "Internet Computer",
  "asset_b_name": "Oracle Corporation",
  "source_name": "Marketcaper.com",
  "source_url": "https://marketcaper.com/icp/orcl",
  "canonical_url": "https://marketcaper.com/icp/orcl",
  "image_url": "https://marketcaper.com/api/mcp/images/icp/orcl",
  "image": {
    "url": "https://marketcaper.com/api/mcp/images/icp/orcl",
    "format": "png",
    "mime_type": "image/png",
    "width": 1380,
    "height": 840,
    "generation_mode": "on_demand",
    "timeout_seconds_recommended": 20
  },
  "short_post": "If ICP matched the market cap of Oracle Corporation, it would be $2,059. Source: https://marketcaper.com/icp/orcl",
  "share_payload": {
    "text": "If ICP matched the market cap of Oracle Corporation, it would be $2,059. Source: https://marketcaper.com/icp/orcl",
    "url": "https://marketcaper.com/icp/orcl",
    "image_url": "https://marketcaper.com/api/mcp/images/icp/orcl"
  },
  "citation_text": "Data from https://marketcaper.com/icp/orcl"
}
Client setup

Connect major AI clients

Use the same Marketcaper endpoint everywhere. Some clients use JSON config files, while others use a UI or one-line CLI command.

ChatGPT

Manual custom connector

Add a custom MCP connector and use this server URL:

https://marketcaper.com/api/mcp

Official setup references: OpenAI MCP docs and full MCP connectors in ChatGPT.

Claude

Claude CLI / Anthropic Messages API

claude mcp add --transport http marketcaper https://marketcaper.com/api/mcp

For Claude artifacts and direct Messages API use, point to https://marketcaper.com/api/mcp and pass response_format: "json" when you want deterministic parser-friendly output.

fetch("https://api.anthropic.com/v1/messages", {
  method: "POST",
  headers: {
    "Content-Type": "application/json",
    "x-api-key": "YOUR_ANTHROPIC_API_KEY",
    "anthropic-version": "2023-06-01",
    "anthropic-beta": "mcp-client-2025-04-04"
  },
  body: JSON.stringify({
    model: "claude-sonnet-4-20250514",
    max_tokens: 1200,
    mcp_servers: [{ type: "url", url: "https://marketcaper.com/api/mcp", name: "marketcaper" }],
    messages: [{
      role: "user",
      content: "Use compare_assets with asset_a="btc", asset_b="eth", include_image=true, response_format="json". Return the tool result JSON."
    }]
  })
});
const toolResult = data.content.find((block) => block.type === "mcp_tool_result");
const parsed = JSON.parse(toolResult.content[0].text);
console.log(parsed.price_if, parsed.source_url, parsed.image?.mime_type, parsed.image?.timeout_seconds_recommended);
Cursor

cursor mcp.json

{
  "mcpServers": {
    "marketcaper": {
      "url": "https://marketcaper.com/api/mcp"
    }
  }
}
VS Code / Copilot

mcp.json

{
  "servers": {
    "marketcaper": {
      "type": "http",
      "url": "https://marketcaper.com/api/mcp"
    }
  }
}
Codex

Add the remote server in one line

codex mcp add marketcaper --url https://marketcaper.com/api/mcp
Machine-readable metadata

Well-known server card

Registries and scanners can use this JSON document to understand the live Marketcaper MCP server without guessing.

https://marketcaper.com/.well-known/mcp/server-card.json
serverInfo.name: marketcaper-mcp
version: 1.4.0
docs path: /mcp
server-card path: /.well-known/mcp/server-card.json