opendexter

name	opendexter
description	Use OpenDexter to find and pay for x402 APIs from any AI agent. Trigger this skill whenever the user asks to find, price-check, or call a paid API; pay in USDC; check or fund a wallet; settle on Solana, Base, Polygon, Arbitrum, Optimism, Avalanche, BSC, or SKALE; or work with a Dextercard. Trigger on mentions of x402, OpenDexter, paid APIs, agent payments, or `npx @dexterai/opendexter`.

OpenDexter

OpenDexter is the public x402 gateway for AI agents. One MCP server, one wallet, eight chains. Search thousands of paid APIs, see the price before paying, call any of them with automatic USDC settlement, and (optionally) drive a real Dextercard from the same surface.

When to use this skill

Anytime the user wants to:

• Find a paid API (e.g. "is there an API for X?", "find me a price feed for ETH", "anything that generates an image?")
• Call an x402 endpoint (paste a URL, run a request that hits a 402)
• Check or fund a wallet for x402 payments
• Manage a Dextercard (issue a card, link a funding wallet, freeze, check status)

If the user mentions x402, OpenDexter, dexter.cash, open.dexter.cash/mcp, paid APIs, USDC payments for APIs, or pasting a URL that returns 402 — this skill applies.

Hosted vs local — which mode am I on?

OpenDexter ships in two flavors. Most of the surface is identical; a few tools and instructions differ. Detect mode from the tool list before answering setup questions.

Mode	URL / install	Wallet model	Tools that exist
Hosted MCP	https://open.dexter.cash/mcp (added as a connector in Claude.ai, ChatGPT, Cursor, etc.)	Session-managed by the gateway. The user pairs through dexter.cash; x402_wallet returns the session's funded balances.	x402_search, x402_check, x402_fetch, x402_pay, x402_access, x402_wallet, card_status, card_issue, card_link_wallet, card_freeze (10 tools)
Local npx	npx @dexterai/opendexter (Claude Code, Cursor, Codex, Windsurf, Gemini CLI)	Local file at ~/.dexterai-mcp/wallet.json (override with DEXTER_PRIVATE_KEY / EVM_PRIVATE_KEY).	All hosted tools plus x402_settings, card_login_request_otp, card_login_complete (13 tools)

Quick detection rule: if x402_settings is registered in the available tools, you're on local npx. If it isn't, you're on hosted. Same applies to card_login_request_otp/card_login_complete.

Setup advice depends on mode:

• Hosted: never tell the user to set environment variables, edit ~/.dexterai-mcp/settings.json, or run a CLI command. They paired through dexter.cash; that's all the bootstrap they need.
• Local npx: the wallet file lives at ~/.dexterai-mcp/wallet.json. Spend cap edits go in ~/.dexterai-mcp/settings.json (or call x402_settings). Env-var override available for production keys.

When in doubt, run x402_wallet — it'll tell you whether you have a session and where to deposit.

Tools, in the order they should be used

1. x402_search — Find APIs

Always start here for discovery. Semantic capability search across the marketplace. Returns two tiers — strongResults (high-confidence capability matches) and relatedResults (adjacent services worth knowing about). Each result includes name, URL, price, network, qualityScore (0–100), verified status, host, tier, similarity, a short why ranking explanation, and a chains[] array with every payment option.

Param	Type	Description
query	string	Natural-language query. e.g. "check wallet balance on Base", "generate an image", "ETH price feed"
limit	number	Max results across both tiers (1–50, default 20)
unverified	boolean	Include unverified resources (default false)
testnets	boolean	Include testnet-only resources (default false)
rerank	boolean	LLM cross-encoder rerank of top results (default true). Set false for deterministic order.

Do not pre-filter by chain or category — the ranker handles synonyms and expansion internally.

2. x402_check — Preview pricing

Probes an endpoint and returns its 402 payment requirements (price per chain, accepted assets, schema hints) without paying. Use this before the first paid call.

Param	Type	Description
url	string	The URL to check
method	string	GET / POST / PUT / DELETE (default GET)

If the endpoint returns 200 with no 402, tell the user it's free. If it returns 401/403, the provider requires its own auth before x402 settlement is offered.

3. x402_fetch — Call and pay

Calls the endpoint and pays automatically from the local wallet. Returns the API response plus a settlement receipt (transaction hash, amount, chain). On success, link the hash to the right explorer:

Chain	Explorer
Solana	solscan.io/tx/<sig>
Base	basescan.org/tx/<hash>
Polygon	polygonscan.com/tx/<hash>
Arbitrum	arbiscan.io/tx/<hash>
Optimism	optimistic.etherscan.io/tx/<hash>
Avalanche	snowtrace.io/tx/<hash>
BSC	bscscan.com/tx/<hash>
SKALE	<chain>.explorer.mainnet.skalenodes.com/tx/<hash>

Param	Type	Description
url	string	The x402 resource URL
method	string	HTTP method (default GET)
body	any	Request body for POST/PUT (object or string)
headers	object	Optional custom headers

If the wallet has no USDC, the call fails. Run x402_wallet first, surface the deposit address for the right chain, and tell the user to fund. Then retry.

4. x402_pay — Alias of x402_fetch

Use whichever name reads more naturally. Same parameters, same behavior.

5. x402_access — Identity-gated endpoints

Some endpoints require a wallet signature (Sign-In-With-X) instead of a per-call payment. Use this tool for those — it presents the wallet proof and returns the response.

Param	Type	Description
url	string	The identity-gated endpoint URL
method	string	HTTP method (default GET)

6. x402_wallet — Multi-chain wallet

Returns deposit addresses and USDC balances across Solana, Base, Polygon, Arbitrum, Optimism, Avalanche. (The facilitator additionally settles on BSC and SKALE when an endpoint requires those chains.)

What "the wallet" means depends on mode:

• Hosted: the session wallet managed by the gateway, provisioned when the user paired through dexter.cash. Funded by deposits to the addresses this tool returns.
• Local npx: the file at ~/.dexterai-mcp/wallet.json, or whatever key is in DEXTER_PRIVATE_KEY / EVM_PRIVATE_KEY if those env vars are set.

Use it:

• Before a fetch, to confirm sufficient funds
• When the user asks "how much do I have?" or "where do I send USDC?"
• After a fetch fails on insufficient funds

If a balance is zero, proactively show the deposit address and tell the user to fund before attempting the call.

7. x402_settings (local npx only)

Read or update the per-call USDC cap that gates automatic payments. Backed by ~/.dexterai-mcp/settings.json and hot-reloaded — no restart needed after a change.

This tool does not exist on the hosted server. If you're on hosted and the user wants to change spend limits, direct them to dexter.cash account settings.

Dextercard tools

Dextercard is the optional payment-card surface — issue a real card backed by your funded wallet, then spend at any merchant. Cards are created via Crossmint and provisioned through the same MCP session.

card_status — Always run this first

Returns the current account stage so the agent knows which next step to suggest. Possible stages:

Stage	Meaning	Next step
no_session	No Dextercard session paired	Local npx: call card_login_request_otp, then card_login_complete. Hosted: surface the pairing URL the tool returns and tell the user to complete pairing on dexter.cash.
onboarding_required	Session exists, account not started	Call card_issue with step: "auto"
pending_kyc	KYC submitted, awaiting verification	Wait, then re-check
pending_finalize	KYC passed, address/terms not submitted	Call card_issue with step: "auto"
not_issued	Eligible but no card yet	Call card_issue with step: "auto"
active	Card live and unfrozen	Use card_link_wallet / card_freeze
frozen	Card paused	Call card_freeze with frozen: false to resume

Always call card_status before card_issue or card_link_wallet. Do not assume state.

card_issue — Drive issuance

Walks the user through KYC and provisioning one step at a time. Use step: "auto" and let the tool decide the right action; only override with explicit step names if the user wants manual control.

card_link_wallet — Authorize a wallet to fund the card

Param	Type	Description
currency	string	Native asset of the wallet (usually "usdc")
amount	number	Spend cap in human-readable units (e.g. 5000 = 5,000 USDC)

Pre-condition: card must be active. Post-condition: linked wallets show up in card_status.wallets.

card_freeze — Pause or resume the card

Pass frozen: true to freeze, frozen: false to resume. Returns updated metadata.

card_login_request_otp / card_login_complete (local npx only)

Bootstrap a Dextercard session from inside the agent without leaving the chat. card_login_request_otp returns a MoonPay URL the user opens in a browser to solve a captcha. card_login_complete exchanges the resulting OTP for a persisted session. After this completes, all card_* tools work as if the user had paired through dexter.cash.

Hosted users don't need these tools. When card_status returns no_session on hosted, it returns a clickable pairing URL — surface that URL to the user and tell them to complete pairing on dexter.cash. After they pair, card_status will return onboarding_required (or further) and the standard card_issue flow continues.

Workflow patterns

"Find me an API for X"

1. x402_search with the user's query
2. Present the top 2–4 results with name, price, quality score, chain
3. Either suggest the top match or ask the user to pick
4. x402_check to confirm the price (and pick the cheapest chain if there are multiple)
5. x402_fetch to call

"Call this URL"

1. x402_check first to surface the price
2. x402_fetch to settle and call

"How much USDC do I have?" / "Where do I send funds?"

1. x402_wallet
2. Surface deposit addresses per chain
3. If a balance is zero, suggest funding via the chain with cheapest gas (Base or Solana for most users)

"I want a Dextercard"

1. card_status — find the current stage
2. From the stage, route to the right next step (see table above)
3. Use card_issue { step: "auto" } to advance, repeat until active
4. card_link_wallet to authorize a funding wallet

"Pay this and freeze my card after"

1. card_status to confirm active
2. x402_fetch for the actual payment
3. card_freeze { frozen: true } to pause

Quality scores

Range	Meaning
90–100	Excellent. Verified, returns correct data.
75–89	Good. Passed verification, reliable.
50–74	Mediocre. Works but has issues.
Below 50	Poor or untested. Use with caution.

A verified: true flag means the resource has passed Dexter's automated quality bot. Most production endpoints sit in the 75+ band.

Supported chains

Wallet funding (any of these accepts USDC and is shown by x402_wallet):

• Solana (preferred — fastest finality, lowest fees for most users)
• Base
• Polygon
• Arbitrum
• Optimism
• Avalanche

The facilitator additionally settles paid calls on:

• BSC (Binance Smart Chain)
• SKALE (Base chain)

Endpoints declare which chains they accept; x402_check shows you the full per-chain price so you can pick the cheapest one.

Pricing

• Most endpoints cost $0.01 – $0.10 per call.
• Compute-heavy endpoints (image gen, large completions, on-chain analytics) cost more — x402_check will show the real number.
• The wallet only needs USDC. The facilitator pays gas on every supported chain.

Quick install

Hosted MCP (recommended for most users)

Add a single URL as a connector — no install, no env vars, no wallet file. Works in Claude.ai, ChatGPT, Cursor, and any MCP-compatible client.

https://open.dexter.cash/mcp

In Claude.ai: Settings → Connectors → Add custom connector, paste the URL. The first time card_status or x402_wallet runs, it'll surface a pairing URL to dexter.cash for one-time setup.

Local npx (for terminal-native agents)

Best for Claude Code, Cursor, Codex, Windsurf, and Gemini CLI when you want the wallet on your own machine.

npx @dexterai/opendexter

Or wire it into an MCP client config:

{
  "mcpServers": {
    "opendexter": {
      "command": "npx",
      "args": ["-y", "@dexterai/opendexter"]
    }
  }
}

The wallet lives at ~/.dexterai-mcp/wallet.json. Override with DEXTER_PRIVATE_KEY (Solana) or EVM_PRIVATE_KEY (EVM chains) env vars for production keys. Spend cap lives in ~/.dexterai-mcp/settings.json or via the x402_settings tool.

Key behaviors to remember

• Search is semantic. Typos and synonyms are handled. Describe what you want in plain English.
• Don't filter by chain in the query — the ranker does that for you.
• Always run x402_check before the first paid call to a new URL so the user sees the price.
• Detect mode before giving setup advice. If x402_settings is in the tool list you're on local npx; otherwise hosted. Don't tell hosted users to set env vars or edit JSON files.
• Insufficient funds = soft failure. Re-route to x402_wallet and surface the deposit address.
• Card tools fail loud on missing session. When card_status returns no_session, run card_login_request_otp (local npx) or surface the pairing URL the tool returns (hosted).
• After settlement, link the explorer URL for the chain that paid (see table under x402_fetch).

For API sellers

Want your API on the marketplace?

1. Visit https://dexter.cash/onboard
2. Add x402Middleware from @dexterai/x402/server to your endpoints
3. Register your resource URL with the facilitator
4. Dexter's quality bot verifies and scores your endpoint automatically — usually within an hour

Listings update in x402_search results once the resource is verified.

Reference

• npm package: https://www.npmjs.com/package/@dexterai/opendexter
• Hosted MCP: https://open.dexter.cash/mcp
• Marketplace explorer: https://x402gle.com
• Onboard a new API: https://dexter.cash/onboard
• Connector pages (for hosted MCP): https://claude.ai/settings/connectors
• Server-side reference docs: docs://opendexter/workflow, docs://opendexter/protocol, docs://opendexter/debugging (resources exposed by the MCP server itself)