The Agentic Layer (Agent Kit) lets you build products where each user gets an AI agent with real Web3 wallets, MCP tools for LLMs, and x402 payments to external APIs. Your backend holds secrets; your users chat or act through your UI.

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Who this is for

  • Teams building agentic apps (chat + on-chain actions).
  • Developers wiring Cursor / Claude to Abstraxn MCP for internal tools.
  • Products that need autonomous transfers, balances, and paid API access per user.

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Choose your path

Pick the track that matches your goal. You can combine paths later (for example MCP in Cursor while building your app).

Build a full app

Dashboard → SDK → sample backend API + sample web app. Per-user agents, chat, signing on your server.

MCP in IDE only

Copy Overview mcp.json, use tools from Cursor. No custom backend required for reads and catalog search.

Terminal CLI

npm i -g @abstraxn/cli — login, chat with MCP tools, manage agents from your shell.

Autonomous transactions

Per-agent auto-sign in chat + delegated tx queue with webhooks for external MCP clients.

x402 & paid APIs

discover_services catalog → paid_fetch → sign paymentPayload on your server with accessKey.
After copying your API key, run the 5-minute smoke test to confirm MCP before deeper integration.

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Complete implementation path

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Architecture

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Credentials

Three different secrets (application API key, per-agent API key, wallet accessKey) are easy to confuse. See the full Credentials cheat sheet — including env vars, headers, and a decision tree.
The dashboard API key is not the wallet accessKey. The app key talks to Agent Kit; each agent’s access key signs on-chain and x402 payments.

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What agents can do

Guardrails: Interaction policies restrict contracts, recipients, and amounts before tool execution. Spend policy caps paid x402 tool budgets. Tool names for each category come from live tools/list — see MCP tools reference. Register agents on-chain and publish a public registration file (MCP endpoint, x402 flag, metadata). See ERC-8004 agent identity.

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Sample applications

Abstraxn provides a sample backend API and sample web app you can clone or adapt: Use them as the canonical integration pattern in Full-stack app integration.

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MCP endpoint

REST Agent Kit base URL uses the same host without /mcp.

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Documentation map

Credentials

Application key vs accessKey — when to use each.

5-minute smoke test

curl tools/list and discover_services after dashboard setup.

Dashboard setup

Account → app → Agentic Stack UI walkthrough.

SDK quickstart

@abstraxn/agent-kit install and createAgent (server wallet).

Off-chain interaction policies

Guardrails before MCP tools — contracts, recipients, amount limits.

Third-party integrations

BYOK vendor APIs — Uniswap, CoinGecko, dashboard Integrations tab.

External wallet

BYO EVM/Solana address — no accessKey; ERC-8004 with your signer.

ERC-8004 identity

On-chain identity, registration file, dashboard Identity tab.

Full-stack integration

Sample NestJS API + Next.js web app.

MCP tools

Tool-by-tool reference.

x402 payments

Paid HTTP and paymentPayload flow.

MCP in Cursor

IDE setup with Overview snippet.

Abstraxn CLI

Terminal login, chat, and MCP tools via @abstraxn/cli.

Troubleshooting

401, agent_id, x402 -32402, interaction policy -32404, funding, signing FAQ.