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HBAR
For developers

The SentX API

Every listing, sale, floor and trait on SentX is reachable over REST. Four ways in, from anonymous market data to earning commission on trades you route.

Read the docs Get a key

OpenAPI 3 spec at api.sentx.io/openapi.json. Agents start at api.sentx.io or read api.sentx.io/llms.txt.

Use SentX in Claude or ChatGPT

Add SentX as a connector with this address, then ask about the market in plain words. You need no key and no account. 

https://mcp.sentx.io/mcp

Then ask, for example:

  • What is the top collection today on SentX?
  • What sold on SentX in the last hour?

The steps for each app are under Connect an agent, below.

Pick your lane

Four ways in

Same API underneath. The key you hold decides what it will do for you.

Public data

Listings, sales activity, collection stats, floor prices, trait rarity and wallet holdings over plain GET requests. A free key from your settings page unlocks it.

Your account, scripted

A user API key from Settings can act for your wallet, one permission at a time. Collection offers are live today: place, top up and cancel collection offers from a script while your NFTs and HBAR never leave your wallet. Each capability is a switch in your settings, off until you flip it.

Affiliate

List, buy and mint for your users from your own app. Once we approve your account, you earn a share of the marketplace fee on the trades you route, settled on chain straight to your wallet at the moment of sale. One rule: trading goes through the API end to end.

AI agents

Built for Claude and any MCP client. A key costs nothing and takes one request, no account needed. The MCP server exposes fourteen tools and is read-only by design: an agent can research the whole market and never spend a tinybar. See what an agent can answer.

Three steps

Connect an agent

Claude and ChatGPT skip the key and sign in at step 2.

1

Create a key

One request. The sxagent- key is shown once, so store it. Unused keys expire after 7 days, and a key left idle for 90 days may stop working. Prefer one you can see and revoke later? Create it from the agent keys card in your settings instead. 

curl -X POST https://api.sentx.io/v1/agent/keys \
  -H "content-type: application/json" \
  -d '{"label": "my research agent"}'
2

Point your client at the MCP server

claude.ai and Claude Desktop: open Settings, then Connectors, and choose Add custom connector. Paste the address, set sign-in to "Sign in when needed" and add it. The first time you ask about SentX, Claude shows a Connect button that opens a SentX page; choose Allow.

ChatGPT: turn on Developer mode (Settings, then Apps, then Advanced settings), create an app with the address and OAuth as its sign-in, and choose Allow on the SentX page.

Claude Code: run the command below, then /mcp, pick sentx and sign in. To use a key instead, add --header "x-api-key: sxagent-..." to the command. 

claude mcp add --transport http sentx https://mcp.sentx.io/mcp

Each connection uses one of the five agent keys a network address can create per day. To end it, remove SentX from the app's connectors.

Cursor, VS Code, Gemini CLI, scripts and your own agents use a free agent key instead. One request creates it, and it goes in the x-api-key header. Cursor and Claude Code's .mcp.json take this block. Other clients use the same URL and header under their own config keys (Gemini CLI calls the URL httpUrl): 

{
  "mcpServers": {
    "sentx": {
      "type": "http",
      "url": "https://mcp.sentx.io/mcp",
      "headers": { "x-api-key": "sxagent-..." }
    }
  }
}

VS Code, in .vscode/mcp.json: 

{
  "servers": {
    "sentx": {
      "type": "http",
      "url": "https://mcp.sentx.io/mcp",
      "headers": { "x-api-key": "sxagent-..." }
    }
  }
}

In code: the OpenAI Responses API and Agents SDK take the key in the MCP tool's headers; the Anthropic Messages API takes it as the MCP server's authorization_token. Every tool is marked read-only, so clients that honor that hint skip the confirmation prompt.

3

Ask it something real

The tools cover collections, floors, listings, trait rarity, sales activity, single NFTs, wallet holdings and open offers. "What is the cheapest Laser Eyes on the floor" is now a one-liner. Plain REST is always there too, documented for machines at api.sentx.io/llms.txt.

Rate limits answer 429 with a retryAfter you should honor. Stuck? Ask on Discord.

Working with the data

Add marketplace context to your NFT application

Use SentX's public API reference to find the data and request formats available for your integration. Start with one question your application needs to answer, then check the documented fields and limits for that endpoint.

Open the API reference.

Match collections by token ID

Keep the Hedera token ID with collection data in your application. A display name is useful to people but is not a reliable join key between services.

When working with individual NFTs, keep the serial and network too. Read an NFT through a mirror node to see the ledger side of the same identifier.

Keep market events distinct from transfers

A marketplace sale and a network transfer answer different questions. Use the documented market-event fields when showing sales or prices, and use ledger data when checking token movement or ownership.

For collection statistics, label the currency, time window and calculation represented. An unavailable response should not become a zero-volume or zero-price claim.

Build for the documented service

Read the current authentication, pagination and limit requirements before integrating an endpoint. Cache appropriate public data and handle errors explicitly.

Do not place private credentials in browser code. Avoid running write or trading operations as part of a documentation preview. A read-only display is a useful first integration to validate. New to the network? Start with the Hedera developer guide.