Connect ChatGPT, Claude & Any LLM

Use this guide when you want end users to talk to their Abstraxn agent from ChatGPT, Claude, or your own product — not only from Cursor.

Three paths: (1) OAuth MCP for ChatGPT / Claude Web, (2) API key MCP for Claude Code / Cursor, (3) Backend bridge (@abstraxn/mcp-client) for any LLM API (OpenAI, Anthropic, Gemini).

Choose your integration

Client	Auth	Setup
Cursor	Application or per-agent API key	MCP in Cursor
Claude Code	Per-agent API key + `--header`	Below
Claude Web / Desktop	OAuth 2.1	Below
ChatGPT (Developer Mode)	OAuth 2.1	Below
Your app (any LLM)	API key on your server	App integration + SDK

Signing (transfer, x402 paymentPayload) still requires your backend with the agent accessKey — see Credentials.

Prerequisites

Dashboard setup — create an agent and copy credentials.
MCP URL from Agentic Stack → Overview (e.g. https://agent-kit.abstraxn.com/mcp).
For OAuth connectors: MCP_OAUTH_ENABLED=true on the deployment. Kong on /mcp must use a pre-function plugin to strip Bearer before key-auth (see MCP integration).

Path 1 — Claude Code (API key)

Use the per-agent API key from createAgent (not the application key):

claude mcp add -s user web3-agent-kit https://agent-kit.abstraxn.com/mcp \
  --header "Authorization: YOUR_PER_AGENT_API_KEY"

Verify:

claude --mcp-debug

Example prompt: “Check my Agent Kit wallet balance on Base.”

Path 2 — ChatGPT & Claude Web (OAuth)

ChatGPT and Claude Web expect a remote MCP server with OAuth 2.1 (no static API key in the connector UI). After consent, the OAuth access_token is the same per-agent API key you pasted on the consent form. ChatGPT sends it as Authorization: Bearer <key> so Kong key-auth (with a Bearer strip pre-function) can validate /mcp without opening the route.

What Abstraxn exposes

Endpoint	Purpose
`GET /.well-known/oauth-protected-resource`	MCP resource metadata (RFC 9728)
`GET /.well-known/oauth-authorization-server`	OAuth server metadata (RFC 8414)
`GET /oauth/authorize`	Consent screen
`POST /oauth/token`	Token exchange (PKCE)
`POST /oauth/register`	Dynamic client registration
`POST /mcp`	MCP JSON-RPC (`Authorization: Bearer <per-agent-api-key>` after OAuth)

ChatGPT

Settings → Apps → Advanced Settings → enable Developer Mode.
Create app → name it Abstraxn Agent Kit.
MCP server URL: https://agent-kit.abstraxn.com/mcp
Authentication: OAuth (ChatGPT discovers metadata automatically).
On first tool use, complete the Authorize redirect.
On the consent page, paste your per-agent API key from the dashboard.
Use the app in chat (e.g. /abstraxn if configured as slash command).

Claude Web & Desktop

Settings → Connectors → Add custom connector.
Name: Abstraxn Agent Kit
URL: https://agent-kit.abstraxn.com/mcp
Click Connect → complete OAuth consent (per-agent API key on consent form).

Dev environment:

https://dev-agent-kit.abstraxn.com/mcp

OAuth scopes

Scopes gate categories of tools, not a fixed name list. New tools are added to Agent Kit over time; clients should call tools/list after connect to see every name available for the granted scopes.

Scope	Category
`mcp:tools:read`	Wallet/chain reads and x402 catalog discovery
`mcp:tools:transfer`	Unsigned transfer intents (signing on your backend)
`mcp:tools:paid`	Fixed-price and external x402 calls

Call tools/list after connect for the live tool names and schemas. See MCP tools reference.

Connector icon (Claude / ChatGPT)

Claude and ChatGPT pick the connector icon from your MCP host — not from the name you type in the UI.

Source	Where it is exposed
OAuth `logo_uri`	`GET /.well-known/oauth-authorization-server`
Public favicon	`GET /favicon.png` and `GET /favicon.ico` on the same host as `/mcp`
MCP `serverInfo.icons`	Returned in the `initialize` JSON-RPC response

Canonical Abstraxn brand assets (used in OAuth logo_uri, MCP serverInfo.icons, and consent UI):

Asset	URL
Favicon / connector icon	`https://abstraxn.com/icon.png`
Light logo (wordmark)	`https://abstraxn.com/_next/static/media/logo.6a015f32.svg`
Dark logo (wordmark)	`https://abstraxn.com/_next/static/media/dark-mode.d252c03d.svg`

OAuth metadata and MCP initialize point at https://abstraxn.com/icon.png by default. The agent-kit host also redirects /favicon.png → that URL (useful when clients fetch favicon from the MCP domain).

Why you might still see an old or generic icon

Kong blocked /favicon.png — if the favicon URL returns 401 Key, Claude falls back to a generic MCP placeholder (colorful triangle / globe). Whitelist GET /favicon.ico and GET /favicon.png from Kong key-auth (same as OAuth discovery paths).
Connector cached the first icon — Claude caches connector metadata. After deploying a new favicon, disconnect and re-add the connector (or toggle off → on in the Connectors menu).
Client rollout — some Claude builds read logo_uri from OAuth metadata; others use /favicon.png or MCP icons[]. Abstraxn exposes all three so icons update as clients adopt each mechanism.

Verify branding endpoints

# Canonical favicon (200 image/png)
curl -sS -D - -o /dev/null "https://abstraxn.com/icon.png"

# OAuth metadata must include logo_uri → abstraxn.com/icon.png
curl -sS "https://agent-kit.abstraxn.com/.well-known/oauth-authorization-server" | jq '.logo_uri'

# Optional: MCP host redirect (302 → abstraxn.com/icon.png; Kong must allow GET without key-auth)
curl -sS -D - -o /dev/null "https://agent-kit.abstraxn.com/favicon.png"

Optional env overrides when self-hosting:

Variable	Default
`MCP_BRAND_FAVICON_URL`	`https://abstraxn.com/icon.png`
`MCP_BRAND_LOGO_LIGHT_URL`	`https://abstraxn.com/_next/static/media/logo.6a015f32.svg`
`MCP_BRAND_LOGO_DARK_URL`	`https://abstraxn.com/_next/static/media/dark-mode.d252c03d.svg`
`MCP_BRAND_DOCUMENTATION_URL`	`https://docs.abstraxn.com/guides/ai/external-agents`

After fixing Kong + redeploying, reconnect the connector in Claude (Settings → Connectors → Abstraxn → disconnect → Add connector).

Path 3 — Any LLM via `@abstraxn/mcp-client`

Install the SDK in your backend (never in the browser):

npm install @abstraxn/mcp-client

import { AgentKitMcpClient, mcpToolsToOpenAi } from '@abstraxn/mcp-client';

const mcp = new AgentKitMcpClient({
  serverUrl: process.env.MCP_SERVER_URL!,
  authToken: process.env.MCP_SERVER_AUTH_TOKEN!,
  defaultAgentId: session.agentKitId, // when using application API key
});

const tools = await mcp.discoverTools(); // live names from tools/list
const openAiTools = mcpToolsToOpenAi(tools);

// LLM returns tool_call → forward to MCP (use names from discoverTools only)
const toolName = tools[0].name;
const outcome = await mcp.callTool(toolName, { agent_id: session.agentKitId });

Works with OpenAI, Anthropic (tools API or OpenAI-compatible proxy), Gemini, OpenRouter, etc. Full chat loop with signing: Full-stack app integration.

Streamable HTTP (2025-06-18)

Agent Kit supports Streamable HTTP for modern MCP clients:

POST /mcp — JSON-RPC; returns Mcp-Session-Id on initialize
GET /mcp — SSE heartbeat stream (optional)
DELETE /mcp — close session

The @abstraxn/mcp-client package handles session headers automatically.

ERC-8004 discovery

Registered agents publish MCP + OAuth metadata in the public registration file:

{
  "services": [
    {
      "name": "MCP",
      "endpoint": "https://agent-kit.abstraxn.com/mcp",
      "version": "2025-06-18",
      "security": {
        "oauth2": {
          "protectedResourceMetadata": "https://agent-kit.abstraxn.com/.well-known/oauth-protected-resource",
          "scopes": ["mcp:tools:read", "mcp:tools:transfer", "mcp:tools:paid"]
        },
        "apiKey": { "header": "Authorization" }
      }
    }
  ]
}

Getting started

SDK & wallets

Third-party integrations

Off-chain policies

Identity

Build your app

MCP

Payments

Help

Connect ChatGPT, Claude & Any LLM

Choose your integration

Prerequisites

Path 1 — Claude Code (API key)

Path 2 — ChatGPT & Claude Web (OAuth)

What Abstraxn exposes

ChatGPT

Claude Web & Desktop

OAuth scopes

Connector icon (Claude / ChatGPT)

Why you might still see an old or generic icon

Verify branding endpoints

Path 3 — Any LLM via `@abstraxn/mcp-client`

Streamable HTTP (2025-06-18)

ERC-8004 discovery

​Choose your integration

​Prerequisites

​Path 1 — Claude Code (API key)

​Path 2 — ChatGPT & Claude Web (OAuth)

​What Abstraxn exposes

​ChatGPT

​Claude Web & Desktop

​OAuth scopes

​Connector icon (Claude / ChatGPT)

​Why you might still see an old or generic icon

​Verify branding endpoints

​Path 3 — Any LLM via @abstraxn/mcp-client

​Streamable HTTP (2025-06-18)

​ERC-8004 discovery

​Related

Choose your integration

Prerequisites

Path 1 — Claude Code (API key)

Path 2 — ChatGPT & Claude Web (OAuth)

What Abstraxn exposes

ChatGPT

Claude Web & Desktop

OAuth scopes

Connector icon (Claude / ChatGPT)

Why you might still see an old or generic icon

Verify branding endpoints

Path 3 — Any LLM via `@abstraxn/mcp-client`

Streamable HTTP (2025-06-18)

ERC-8004 discovery

Related