Contracts

Overview

The Contracts module provides a flexible and standardized interface for interacting with smart contracts across EVM-compatible blockchains. It allows you to upload contract ABIs, register on-chain deployments, and invoke both read-only and state-changing methods — all through FSCO’s API infrastructure.

Key Features

• ABI Management: Upload and manage contract ABIs for consistent interface handling
• Deployment Registration: Track deployed contracts across chains with metadata
• State-Changing Calls: Execute transactions like transfer, approve, or custom methods
• Read-Only Queries: Query on-chain data using view or pure methods without gas
• Transaction Receipts: Retrieve full execution metadata for contract calls
• Multi-Chain Support: Use contracts across multiple EVM networks

Core Concepts

ABI (Application Binary Interface)

• An ABI defines the available functions and structure of a contract
• Uploaded once and reused for any matching deployment
• Contains method names, input/output types, and mutability flags
• Identified by a unique abiId

Deployment

• A Deployment links an ABI to a specific on-chain contract address on a given chain
• Required to perform contract calls or queries
• Includes metadata such as name, chainId, contractAddress, and abiId
• Identified by a unique deploymentId

Call vs Query

Operation	Description	State Change	Gas Cost
Call	Executes a method (e.g. transfer, mint)	✅ Yes	✅ Yes
Query	Reads contract data (e.g. balanceOf)	❌ No	❌ No

Execution Flow

1. Upload an ABI: Defines the contract’s interface
2. Register a Deployment: Connects the ABI to a specific on-chain contract
3. Call or Query Methods: Interact with the contract via FSCO API
4. Fetch Transaction Receipts (for state-changing calls): Confirm execution status

How It Works

ABI Upload

• Use POST /v2/contract/abi to upload a contract interface
• Receives a unique abiId used in subsequent deployments
• Shared ABIs can be reused across environments

Deployment Registration

• Use POST /v2/contract/deployment to register a deployed contract
• Requires chain ID, contract address, and abiId
• Enables later method invocations

Method Execution

• Use POST /contract/deployment/{id}/call for transactions
• Use POST /contract/deployment/{id}/query for read-only calls
• Pass method name and ordered parameters

Receipt Retrieval

• Use GET /contract/tx/{txId}/receipt to retrieve status, gas used, logs, and block info

Common Use Cases

• Token Transfers: Call transfer() on ERC-20 contracts
• Ownership Checks: Query ownerOf() or balanceOf() methods
• DAO & Governance: Submit proposals or cast votes via smart contract methods
• Data Feeds & Oracles: Pull live data via query calls
• Cross-Chain Apps: Register the same ABI across multiple deployments on different networks

Getting Started

1. Deploy a Smart Contract
2. Call a Contract Method
3. Query a Contract Method
4. Get Transaction Receipt
5. Reuse an Existing Deployment

API Reference

For full endpoint details, see the Contracts API Reference

Best Practices

• Use meaningful names for ABIs and Deployments to simplify search and reuse
• Store deploymentId and abiId securely — they are required for all operations
• Prefer queries for reading data to avoid unnecessary gas costs
• Keep deployments and ABIs shared if needed across teams or environments

Limitations

• Currently supports only EVM-compatible chains
• Contract deployment is handled externally — FSCO does not deploy on-chain for you
• Only contracts with known ABIs can be interacted with via this module