> ## Documentation Index
> Fetch the complete documentation index at: https://docs.biconomy.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction to Biconomy

> The full-stack infrastructure for building seamless Web3 experiences across chains

Biconomy provides the infrastructure to build Web3 applications with Web2-level user experience. Execute complex multi-chain workflows with a single signature, abstract away gas entirely, and enable automation through delegated permissions.

<CardGroup cols={2}>
  <Card title="70M+" icon="chart-line">
    Transactions processed
  </Card>

  <Card title="4.5M+" icon="wallet">
    Smart accounts deployed
  </Card>
</CardGroup>

## Core Components

### Nexus Smart Account

[Nexus](/new/learn-about-biconomy/nexus) is Biconomy's ERC-7579 compliant smart account—the most gas-efficient on the market with **25% lower costs** than alternatives.

<CardGroup cols={2}>
  <Card title="Gasless Transactions" icon="gas-pump">
    Users pay fees in USDC, USDT, or any ERC-20 token—or you sponsor gas entirely
  </Card>

  <Card title="Composable Batching" icon="layer-group">
    Chain multiple operations where each step uses outputs from the previous one
  </Card>

  <Card title="Modular Architecture" icon="puzzle-piece">
    Install modules for recovery, spending limits, session keys, and custom logic
  </Card>

  <Card title="Cross-Chain Ready" icon="globe">
    Unified addresses across all supported EVM networks
  </Card>
</CardGroup>

### Orchestration

The Biconomy stack enables advanced onchain orchestration capabilities. These include:

* Executing multiple composable transactions in an atomic batch (Composable Batching)
* Executing multiple function calls across multiple chains with a single user signature (Cross-Chain Orchestration)
* Scheduling transactions or creating repeat transactions.
* Setting up "Conditional Execution" - triggering transactions based on some on-chain condition (e.g. price oracles)

The orchestration capabilities are enabled by the Biconomy **Modular Execution Environment** (MEE).

[MEE](/new/learn-about-biconomy/mee-vs-4337) is the execution layer that goes beyond ERC-4337. While ERC-4337 introduced account abstraction, MEE enables true cross-chain composability.

| Capability                   | ERC-4337 | MEE |
| ---------------------------- | -------- | --- |
| Batch transactions           | ✅        | ✅   |
| Dynamic composable execution | ❌        | ✅   |
| Cross-chain orchestration    | ❌        | ✅   |
| Pay gas from any chain       | ❌        | ✅   |
| EOA wallet support           | ❌        | ✅   |

<Tip>
  With MEE, your users sign once to execute operations across multiple chains. Bridge timing, gas management, and execution ordering are handled automatically.
</Tip>

## Choose Your Integration Path

Biconomy offers two ways to integrate, depending on your needs:

<Tabs>
  <Tab title="Supertransaction API">
    **Best for:** Rapid development, DeFi integrations, teams without blockchain expertise

    * REST API works with any language or framework
    * Pre-built integrations for hundreds of DeFi protocols
    * Automatic bridge and swap route optimization
    * No smart contract deployment or encoding required

    ```bash theme={null}
    # Quote → Sign → Execute
    curl -X POST https://api.biconomy.io/v1/quote \
      -d '{"composeFlows": [...]}'
    ```
  </Tab>

  <Tab title="AbstractJS SDK">
    **Best for:** Custom logic, fine-grained control, TypeScript applications

    * Viem-inspired API with full type safety
    * Direct smart account management
    * Custom calldata encoding and gas limits
    * Integrates with existing viem/ethers workflows

    ```typescript theme={null}
    import { createMeeClient } from "@biconomy/abstractjs"

    const client = await createMeeClient({ account })
    await client.execute({ instructions: [...] })
    ```
  </Tab>
</Tabs>

<Info>
  Not sure which to choose? See the [detailed comparison](/new/learn-about-biconomy/choosing-stack).
</Info>

## Smart Sessions for Automation

[Smart Sessions](/new/smart-sessions/introduction) enable delegated execution—perfect for AI agents, bots, and automated strategies. Users grant scoped permissions to other signers with precise constraints.

<Steps>
  <Step title="Define Permissions">
    Specify which contracts, functions, and token limits the agent can access
  </Step>

  <Step title="User Approves (Single Signature)">
    User signs once to grant the session—fully gasless
  </Step>

  <Step title="Agent Executes">
    Agent operates within boundaries without requiring additional user signatures
  </Step>
</Steps>

**Example:** An AI agent that rebalances funds across DeFi protocols:

* Limited to AAVE, Morpho, and Yearn contracts
* Can only move USDC
* Maximum spend of 10,000 USDC
* Works across Optimism, Base, and Ethereum

<Note>
  Smart Sessions work with both Smart Accounts and EOAs (via EIP-7702 or Fusion Execution).
</Note>

## Next Steps

<CardGroup cols={2}>
  <Card title="Swaps & Trading" icon="arrow-right-arrow-left" href="/swaps-trading">
    Build cross-chain swap experiences
  </Card>

  <Card title="Zaps" icon="bolt" href="/zaps">
    One-click DeFi workflows
  </Card>

  <Card title="Agents & Automation" icon="robot" href="/agents-automation">
    Delegated execution for bots and AI
  </Card>

  <Card title="Gasless Apps" icon="gas-pump" href="/gasless-apps">
    Sponsor transactions for your users
  </Card>
</CardGroup>