How to Design an Intent Standardization Framework

An intent standardization framework provides a structured language for users to declare their desired end-state on a blockchain, such as "swap X token for Y token at the best rate" or "deposit assets into the highest-yielding vault." Unlike traditional transactions, which specify exact execution steps, an intent delegates the how to a network of specialized solvers. The core design challenge is creating a declarative, composable, and verifiable schema that solvers can reliably interpret and compete to fulfill. This requires a clear separation between the user's signed declaration (the intent) and the solver's proposed fulfillment transaction.

The framework's architecture typically consists of several key components. First, a standardized data schema defines the structure of an intent object, including fields for the signer, a unique nonce, a deadline, and the core declarative constraints. Second, a constraint language allows users to specify conditions like token amounts, price limits, counterparties, or required protocols. Third, a fulfillment verification mechanism ensures that any submitted transaction genuinely satisfies the intent's constraints before it is executed on-chain. Projects like Anoma and SUAVE are pioneering different approaches to this architecture.

Designing the constraint language requires balancing expressiveness with solver efficiency. A framework that is too permissive can lead to ambiguous intents that are difficult to solve or verify. A common approach is to use a domain-specific language (DSL) or a set of predefined intent "primitives" that can be composed. For example, a Swap primitive might require parameters for inputToken, outputToken, and minOutputAmount. A more complex intent could chain a Swap primitive with a Deposit primitive into a lending protocol. The ERC-4337 standard for account abstraction, with its UserOperation struct, provides a foundational layer upon which intent standards can be built.

Verification is critical for trustlessness. The framework must include a deterministic verification function that any network participant can run. This function takes the original signed intent and a candidate fulfillment transaction as input, and returns a boolean indicating if the transaction is valid. This often involves simulating the transaction against a local state to check final balances or state changes. For example, to verify a swap intent, the function would check that the user's outputToken balance increased by at least the minOutputAmount specified, regardless of the internal routing the solver used.

Finally, a successful framework must incentivize a healthy ecosystem. This involves a solver network that competes to find the optimal fulfillment path, often bidding via a fee or rebate. The design must prevent MEV extraction from users and ensure solver profitability is aligned with user outcomes. Mechanisms like commit-reveal schemes for solver submissions and a decentralized intent mempool are active areas of research. By standardizing these components, developers can create interoperable applications where user intents flow seamlessly across different solvers and blockchains, moving beyond rigid transaction scripts.

An intent is a declarative expression of a user's desired outcome, not a specific set of instructions. Instead of signing a transaction to swap 1 ETH for USDC on Uniswap V3 with a 1% slippage tolerance, a user expresses the intent: "I want the best price for 1 ETH in USDC within the next block." The core shift is from specifying how to achieve a goal to declaring what the goal is. This moves complexity off-chain to specialized solvers, enabling better execution, gas efficiency, and cross-chain operations. The ERC-4337 account abstraction standard is a critical enabler, as it separates the validation logic of an account from its execution, creating a natural home for intent-based user operations.

Designing a framework requires standardizing the intent schema and fulfillment lifecycle. A schema defines the structure of an intent object, typically including fields like sender, deadline, constraints (e.g., minimum output), and a signature. The lifecycle involves three key phases: 1) Publication, where a signed intent is broadcast to a network. 2) Solving, where competing solvers (bots, searchers, specialized protocols) compute and bid on fulfillment paths. 3) Settlement, where the winning solver's transaction bundle is executed on-chain, and the user's intent is satisfied. This creates a competitive marketplace for execution quality.

A major technical challenge is ensuring verifiable fulfillment. The system must cryptographically prove that the settled outcome matches the user's declared constraints. This often involves zero-knowledge proofs for private intents or optimistic schemes with dispute periods. Furthermore, the framework must be chain-agnostic; an intent to "bridge assets from Ethereum to Arbitrum at the best rate" should be solvable across both ecosystems. This requires a standard that can be implemented as a smart contract on any EVM-compatible chain and understood by cross-chain messaging protocols like LayerZero or CCIP.

Consider a practical example: a limit order intent. In a traditional DEX, a limit order is a specific contract. In an intent framework, the user signs a message: "Sell 100 USDC for at least 0.05 ETH before block 20,000,000." Solvers monitor this intent. When the market price hits the target, a solver submits a bundle that performs the swap on the most liquid pool (which could be Uniswap, Curve, or a private OTC desk) and pays the user the ETH. The user never specified the pool or the exact swap path, only their desired economic outcome. The solver's profit is the difference between the execution cost and a fee taken from the output.

Finally, security and user experience are paramount. The framework must protect users from malicious solvers who might try to front-run, censor, or provide suboptimal execution. Mechanisms like solver staking, reputation systems, and decentralized solver networks are essential. From a UX perspective, wallets and dApps must generate and sign standardized intent objects seamlessly. The end goal is a world where users interact with blockchain applications by stating objectives, not composing low-level transactions, abstracting away the underlying complexity of the decentralized stack.

An intent domain is a specific category of user objectives that share common properties and constraints. For example, in decentralized finance (DeFi), common domains include token swaps, liquidity provisioning, and leveraged yield farming. Each domain has unique requirements: a swap intent specifies a source token, a target token, and acceptable slippage, while a yield farming intent might specify a pool, a capital amount, and a risk tolerance. Defining these domains is crucial because it allows for the creation of specialized, efficient solvers and clear communication standards between users and the network.

Scoping the framework involves deciding which domains to support initially and which system components will handle them. A practical approach is to start with a minimal viable scope—supporting one or two high-demand domains like simple swaps or limit orders. This allows for iterative development and testing. The scope must also define the architectural boundaries: Will the framework handle intent expression, routing, fulfillment, and settlement? Or will it focus solely on a standard for expressing intents, leaving execution to external solver networks? Clarity here prevents scope creep and ensures the framework remains implementable.

To formalize this, create a domain specification document. For each domain, document the core parameters (e.g., inputToken, outputToken, deadline), the constraints (e.g., minAmountOut, allowedDEXs), and the fulfillment conditions. This specification acts as a schema. In practice, this can be represented as a structured data object. For a swap intent, a simplified JSON schema might look like:

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{
  "domain": "swap",
  "parameters": {
    "sellToken": "string",
    "buyToken": "string",
    "sellAmount": "string",
    "buyAmountMin": "string"
  },
  "constraints": {
    "deadline": "number",
    "allowedFillers": "string[]"
  }
}

This structured definition is the first concrete artifact of your standardization effort.

An intent schema defines the data model for user objectives. It must be expressive enough to capture complex user goals—like "swap 1 ETH for the best price on Uniswap V3 or Curve within 5 minutes"—while remaining structured for automated processing. The core components typically include: a sender address, a deadline timestamp, a set of constraints (e.g., minimum output amount), and a list of permissions granted to a solver. This structure moves beyond simple transaction calldata to a declarative statement of desired outcomes.

Standardization is key for ecosystem growth. By adopting a common schema—such as one inspired by ERC-4337's UserOperation or the emerging ERC-7521 for intents—applications and solvers share a universal language. This allows a wallet to create an intent that can be fulfilled by any compatible solver network, fostering competition and efficiency. The schema should be chain-agnostic where possible, using generic types for assets and addresses to enable cross-chain intent expression.

Here is a simplified example of an intent schema defined in a Solidity interface or a JSON Schema. It outlines the required fields for a basic swap intent.

solidityCopy
struct Intent {
    address sender;
    uint256 nonce;
    uint256 deadline;
    IntentAsset[] inputs;
    IntentAsset[] outputs;
    bytes32 root; // For merkle tree of constraints
    bytes signature;
}

struct IntentAsset {
    address token;
    uint256 amount;
    uint256 chainId;
}

This structure explicitly separates the user's deposited inputs from the expected outputs, with constraints potentially verified against a root hash.

Constraints and Permissions must be carefully scoped to ensure security. A constraint is a rule the final outcome must satisfy, such as outputAmount >= 1000 USDC. Permissions define what actions a solver is authorized to perform on the user's behalf, like accessing a specific ERC-20 allowance or interacting with a pre-approved set of DEX routers. The schema should enforce least-privilege principles, preventing solvers from accessing funds or contracts outside the intent's scope. This is often managed through signed attestations or merkle proofs of allowed paths.

Finally, the schema must account for composability and partial fulfillment. A complex intent might be broken down into sub-intents handled by specialized solvers. The design should allow for intent aggregation and conditional logic, enabling use cases like "execute this trade only if the total fee is below 0.5%." By designing a robust, extensible schema foundation, you create the groundwork for a secure and versatile intent-centric ecosystem where users retain control while delegating execution complexity.

A robust intent framework requires a standardized parameter schema that abstracts away protocol-specific details. Instead of defining an intent as "swap 1 ETH for USDC on Uniswap V3," you define it as a SwapIntent with generic fields: inputToken, outputToken, inputAmount, and minOutputAmount. This abstraction is crucial. It allows a solver to fulfill the intent on Uniswap, Curve, or a private OTC desk, whichever offers the best execution. The schema acts as a common language, decoupling the user's goal from the implementation details of any single protocol.

Condition expressions add a layer of programmable logic to intents, enabling complex, state-dependent actions. These are declarative rules evaluated against on-chain or oracle data. A simple condition might be block.timestamp > 1672531200 to set an expiry. More advanced conditions enable limit orders: tokenPrice >= 2000. The key is that conditions are evaluated, not executed; they define the guardrails for fulfillment. The Ethereum ABI provides a useful model for encoding these expressions and their parameters in a standardized, compact format that can be efficiently verified on-chain.

Here is a conceptual example of a standardized intent object combining parameters and conditions:

jsonCopy
{
  "standard": "ERC-7521",
  "type": "SwapIntent",
  "parameters": {
    "inputToken": "0x...ETH",
    "outputToken": "0x...USDC",
    "inputAmount": "1000000000000000000",
    "minOutputAmount": "1800000000"
  },
  "conditions": [
    {
      "id": "price-floor",
      "expression": "outputAmount >= parameters.minOutputAmount",
      "dataSource": {"oracle": "Chainlink", "feed": "ETH/USD"}
    },
    {
      "id": "deadline",
      "expression": "block.timestamp <= 1672531200"
    }
  ]
}

This structure is solver-agnostic. A solver's job is to find a transaction path that satisfies all conditions while fulfilling the parameterized intent.

Designing the condition evaluation system requires careful consideration. Expressions must be deterministic and their data sources verifiably authentic. Using decentralized oracles like Chainlink or Pyth for price data is standard. For more complex logic, you might reference the state of a specific smart contract. The evaluation can happen off-chain by solvers during the search phase, but critical conditions must be re-evaluated and enforced in the on-chain settlement contract. This ensures that even if a solver acts maliciously, the settlement will fail if conditions aren't met, protecting the user.

Finally, this standardization enables composability. A standardized SwapIntent can be seamlessly nested as a step within a larger MultiStepIntent that also includes a bridge action or a liquidity provision. Solvers and specialized "intent orchestrator" contracts can decompose these complex intents, route sub-intents to specialized solvers, and aggregate results. By establishing clear, shared schemas and expression formats, you create a foundation where intents become interoperable building blocks, unlocking more sophisticated and user-centric DeFi applications.

An intent standardization framework defines a common language for wallets and solvers. The core is a structured data schema, like an Intent object, that encapsulates the user's desired outcome. This object should include fields for the chain ID, deadline, a list of constraints (e.g., minOutputAmount), and the intent expression itself. The expression is the key, often using a domain-specific language (DSL) or a structured format like JSON to describe the desired state change, such as swap X token for at least Y token on any DEX. Standardizing this schema allows any compliant wallet to generate intents and any compliant solver to interpret them.

For wallets, the interface involves generating and signing these intent objects. A wallet must expose methods like createIntent() to construct the object and signIntent() to cryptographically commit the user to their desired outcome without specifying the path. The signature typically follows EIP-712 for structured data signing, ensuring clarity about what is being signed. Wallets also need to broadcast the signed intent to a solver network, which requires a standard relay endpoint or a peer-to-peer gossip protocol. This separation allows wallets to focus on user experience and security, not on finding execution paths.

On the solver side, the interface is about fulfillment. Solvers must implement a standard solve() or fulfill() function that takes a signed Intent object as input. Their role is to discover and execute a transaction that satisfies the intent's constraints. They return a fulfillment proof—often the calldata and target address for a transaction—back to the user or a settlement layer. A critical standard here is the format for expressing solver competition, such as a sealed-bid auction where solvers submit commitments to their solution and associated fee, revealed only after a deadline.

Practical implementation often references existing EIPs and community efforts. EIP-4337 (Account Abstraction) provides a model for user operation objects and bundlers, which is analogous to intents and solvers. Projects like Anoma and SUAVE propose their own intent-centric architectures and DSLs. For a simpler start, you can define a basic JSON-RPC interface for your wallet and solver. For example, a wallet's eth_sendIntent method could mirror eth_sendTransaction but accept an intent object. Open-source libraries defining these schemas are essential for ecosystem growth.

The ultimate goal of standardization is composability. A standardized intent from Wallet A should be solvable by Solver Network B and settled on Settlement Layer C. This requires agreement on core primitives: the intent schema, signature format, fulfillment proof, and relay mechanism. Without this, the ecosystem fragments into isolated intent silos. By adopting shared standards, developers can build specialized solvers for specific domains (e.g., NFT arbitrage, cross-chain swaps) that seamlessly plug into a broader network, dramatically expanding the solution space available to users.

The core of a secure intent framework is a validation layer that programmatically verifies the integrity of every intent before it is executed. This layer must check three primary conditions: signature validity, ensuring the intent originated from the authorized user; parameter constraints, verifying that all specified conditions (like slippage limits or deadline) are within acceptable bounds; and state consistency, confirming the intent is still valid given the current on-chain state (e.g., the user still has sufficient funds). This pre-execution validation prevents malformed or malicious intents from entering the system.

For complex intents involving cross-chain actions or multi-step workflows, you must implement atomicity guarantees. This ensures that either all steps of an intent succeed or the entire operation reverts, protecting users from partial executions that could leave assets stranded. Techniques like using condition checks and time locks within a solver's settlement contract are essential. For example, a cross-chain swap intent should validate that the destination chain's liquidity pool has sufficient depth before committing funds on the source chain, often requiring oracle or pre-confirmation from the solver.

A robust framework incorporates solver reputation and slashing. Solvers are the entities that fulfill intents, and their behavior must be incentivized to be honest. Implement a staking mechanism where solvers post a bond. If a solver is found to have submitted an invalid fulfillment (e.g., front-running, providing suboptimal quotes, or censoring transactions), a portion of their stake can be slashed. This economic security model, similar to those in Proof-of-Stake networks, aligns solver incentives with user safety. Projects like Anoma and SUAVE explore such cryptoeconomic designs.

Finally, integrate runtime monitoring and fraud proofs. Even with pre-validation, post-execution analysis is crucial. Develop off-chain monitors that audit solver performance and fulfillment outcomes against the original intent. For decentralized validator networks, implement a fraud proof system where any watcher can challenge an incorrect fulfillment on-chain. If the challenge is successful, the fraudulent solver is penalized, and the challenger is rewarded. This creates a scalable security model where the cost of verification is distributed, a concept leveraged by optimistic rollups like Arbitrum.

Designing an intent standardization framework is an iterative process that balances user abstraction with on-chain execution constraints. The key components you should now have in mind are: a declarative language for expressing user goals, a solver network to find optimal execution paths, a verification layer to ensure outcomes match the declared intent, and a standardized data schema (like EIP-712 for signed messages) for interoperability. Successful frameworks, such as those used by Anoma or SUAVE, treat the intent as a first-class object that can be composed, routed, and settled by specialized agents.

To begin implementing a basic framework, start by defining your intent schema. Use a structured format like JSON Schema or Protobuf to specify the fields, constraints, and signing requirements. For example, a simple swap intent could include fields for inputToken, outputToken, minimumOutputAmount, deadline, and userSignature. This schema becomes the contract between the user and the solver. The next step is to build a solver client that subscribes to a public intent mempool, evaluates paths using on-chain and off-chain data, and submits transaction bundles that fulfill the intent for a profit.

Testing and security are paramount. Develop a simulation environment using a forked blockchain (with tools like Foundry's forge or Hardhat) to test solver logic against edge cases and potential exploits. Implement intent fulfillment verification by comparing the post-execution state against the user's signed constraints. Consider auditing critical components, especially the settlement contract that holds user funds in escrow. Resources like the Ethereum Foundation's Security Guidelines and audits of existing intent-based protocols provide essential guidance.

The future of intent-centric design points toward greater composability and chain abstraction. As standards mature, intents from different applications could be bundled into a single user session, and solvers could execute across multiple blockchains seamlessly. To stay current, follow developments in related EIPs, research from projects like Cow Protocol and UniswapX, and academic work on mechanism design. The goal is to move from a transaction-based web3 to a result-based one, where users specify what they want, not how to get it.