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

# API Changelog

> Track OneBalance API updates, new endpoints, breaking changes, and feature releases with detailed migration guides

Subscribe to API updates via RSS at [https://docs.onebalance.io/changelog/api/rss.xml](https://docs.onebalance.io/changelog/api/rss.xml).

<Update label="2026-02-19" description="v1.6.2" tags={["Improvements"]}>
  ## Improvements

  * Migrate `x-mcp` to `x-mint.mcp` in OpenAPI spec
</Update>

<Update label="2025-09-25" description="v1.6.1" tags={["Improvements"]}>
  ## Improvements

  * Add complete list of all fail reason codes with detailed descriptions and categories (General Failure Reasons, Execution Revert Specific Reasons, Jupiter Specific Failures)
  * Add documentation link to [https://docs.onebalance.io/api-reference/error-codes](https://docs.onebalance.io/api-reference/error-codes) for detailed explanations and troubleshooting steps
  * Add "CALL" enum value to action.yaml and action-v3.yaml for contract call operations
  * Enhance API documentation with better categorization and explanations for developers
</Update>

<Update label="2025-09-23" description="v1.6.0" tags={["Feature"]}>
  ## New Features

  **Fail Reason Field:**

  * Add optional `failReason` field to execution status responses when status is REFUNDED
  * Add fail-reason enum schema with 12 standardized refund reasons (SLIPPAGE, INSUFFICIENT\_BALANCE, TIMEOUT, etc.)
  * Updated both v1 and v3 status endpoints ([`/status/get-execution-status`](/api-reference/status/get-quote-status) and [`/v3/status/get-execution-status`](/api-reference/status/get-quote-status-v3))
  * Updated transaction history endpoints ([`/status/get-tx-history`](/api-reference/status/get-tx-history) and [`/v3/status/get-tx-history`](/api-reference/status/get-tx-history-v3)) to include failReason in historical records
  * Added response examples showing refunded transactions with detailed fail reasons
  * Backward compatible: field only appears when status is REFUNDED
  * Enhanced [error handling documentation](/api-reference/errors) with quote execution failure guidance
  * See [Refund Reasons Guide](/guides/quotes/refund-reasons) for detailed explanations and handling strategies
</Update>

<Update label="2025-09-22" description="v1.5.0" tags={["Feature"]}>
  ## New Features

  **Slippage Tolerance Configuration:**

  * Add optional `slippageTolerance` parameter to all quote request models (V1, V2, V3)
  * Parameter accepts positive integer values in basis points (e.g., 50 = 0.5%, 100 = 1%, 1000 = 10%)
  * Helps reduce quote refunds and improve user experience by allowing configurable slippage tolerance
  * Available on [quote endpoints](/api-reference/quotes/get-quote), [call-quote endpoints](/api-reference/quotes/get-call-quote), and [prepare-call-quote endpoints](/api-reference/quotes/prepare-call-quote)
  * Also supported on V3 endpoints: [`/v3/quote`](/api-reference/quotes/get-quote-v3), [`/v3/quote/call-quote`](/api-reference/quotes/get-call-quote-v3), and [`/v3/quote/prepare-call-quote`](/api-reference/quotes/prepare-call-quote-v3)
  * Backward compatible - parameter is optional to maintain existing integrations
  * See [Slippage Tolerance Guide](/guides/slippage/overview) for detailed configuration and best practices

  ## Improvements

  * Create shared slippage tolerance model to avoid code duplication across API versions
  * Remove deprecated `transfer-quote` and `swap-quote` endpoints and their associated models
  * Fix status schema validation in transaction history examples
  * Correct nested status structure to flat format across all history responses
  * Add missing chain properties to chain operations in examples
</Update>

<Update label="2025-09-18" description="v1.4.3" tags={["Improvements"]}>
  ## Improvements

  * Added `symbol`, `name`, and `decimals` fields to the destination-asset-used model to match actual API responses. These optional fields provide token metadata when available.
</Update>

<Update label="2025-09-17" description="v1.4.2" tags={["Improvements"]}>
  ## Improvements

  * Fix status field structure: changed from object wrapper to direct string enum
  * Add missing `chain` field to v1 operation-details model
  * Add missing `chainId` field to v3 operation-details model for backwards compatibility
  * Fix all response examples that incorrectly showed `status.status` instead of direct `status` string
  * Add multi-input response example showing cross-chain aggregation from multiple source chains
</Update>

<Update label="2025-09-08" description="v1.4.1" tags={["Improvements"]}>
  ## Improvements

  * Updated account models
</Update>

<Update label="2025-09-03" description="v1.4.0" tags={["Improvements"]}>
  ## Improvements

  Enhanced documentation for chain-specific token spending capability and V3 prepare-call-quote endpoint

  **Chain-Specific Token Spending:**

  * Added explicit mentions of chain-specific asset spending in [quote endpoint](/api-reference/quotes/get-quote) descriptions
  * Enhanced asset field descriptions with clear choice explanations between [aggregated and chain-specific assets](/concepts/aggregated-assets)
  * Added "Asset Flexibility" section to [V1 quote endpoint](/api-reference/quotes/get-quote) highlighting both aggregated and specific asset options
  * Enhanced [V3 quote endpoint](/api-reference/quotes/get-quote-v3) with prominent "Chain-specific token spending" capability callout
  * Improved asset field descriptions across quote models with concrete CAIP-19 examples
  * Better documentation of when to use aggregated vs chain-specific assets for optimal user guidance

  **V3 Prepare-Call-Quote Documentation:**

  * Created separate [V3 prepare-call-quote endpoint](/api-reference/quotes/prepare-call-quote-v3) documentation at `/v3/quote/prepare-call-quote`
  * Added [multi-account support](/concepts/accounts) with mixed Solana and EVM accounts
  * Documented cross-chain contract call capabilities with source asset bridging
  * Added examples for Solana USDC/SOL to EVM contract execution
  * Included [EIP-7702 delegation support](/guides/eip-7702/overview) documentation
  * Created V3-specific request and response models with multi-account schemas

  **V3 Call-Quote Documentation:**

  * Created separate [V3 call-quote endpoint](/api-reference/quotes/get-call-quote-v3) documentation at `/v3/quote/call-quote`
  * Added [multi-account call execution](/concepts/accounts) with cross-chain support
  * Documented complex DeFi interactions using multiple account types
  * Included [EIP-7702 delegation workflow](/guides/eip-7702/getting-started) examples
  * Created call-request-v3.yaml model for multi-account call requests
  * Enhanced error handling for multi-account configuration validation
</Update>

<Update label="2025-09-01" description="v1.3.1" tags={["Feature"]}>
  ## New Features

  Add aggregatedAssetId filtering to v3 aggregated balance endpoint and clarify token amount formatting

  **Breaking change for v3 aggregated balance endpoint:**

  * Add `aggregatedAssetId` parameter to [`/api/v3/balances/aggregated-balance`](/api-reference/balances/aggregated-balance-v3) endpoint for filtering specific [aggregated assets](/concepts/aggregated-assets)
  * Parameter supports comma-separated list of aggregated asset IDs (e.g., "ob:eth,ob:usdc,ob:arb")
  * When provided, response only includes the specified aggregated assets instead of all available assets
  * **Validation requirement:** At least one of `assetId` or `aggregatedAssetId` must be provided and non-empty
  * Add 400 Bad Request response for validation errors when neither parameter is provided
  * Add missing `accounts` field to response schema containing parsed EVM and Solana addresses
  * Update all response examples to match actual API behavior with correct asset ID prefixes and response structure
  * Add realistic examples based on actual API responses for both filtered and specific asset queries

  **Token amount documentation improvements:**

  * Update token amount field descriptions in schemas to specify that amounts should be provided in the smallest unit considering token decimals
  * For example, if a token has 6 decimals, "1" token should be represented as "1000000"
</Update>

<Update label="2025-08-07" description="v1.3.0" tags={["Feature"]}>
  ## New Features

  Add EIP-7702 support and improve multi-chain patterns for OpenAPI specification

  **EIP-7702 Features:**

  * Add delegation and delegation-signature models for [EIP-7702 authorization flow](/guides/eip-7702/overview)
  * Enhance [account models](/concepts/accounts) with deploymentType field to distinguish ERC4337 vs EIP7702 accounts
  * Update chain-operation model with optional delegation field for execution
  * Add EIP-7702 examples to [prepare-call-quote](/api-reference/quotes/prepare-call-quote) and [call-quote](/api-reference/quotes/get-call-quote) endpoints showing delegation workflow
  * Include cross-references to [EIP-7702 integration guides](/guides/eip-7702/getting-started) for detailed implementation steps

  **Multi-chain Improvements:**

  * Update hash patterns to support both EVM (0x format) and Solana (base58) transaction hashes
  * Update user address patterns to support both EVM and Solana address formats
  * Add callType enum and sourceAssetBalances to [prepare-call-quote](/api-reference/quotes/prepare-call-quote) responses
  * Make factory/factoryData optional in UserOperation schema for deployed accounts
  * Remove staging server references from [v3 endpoints](/api-reference/quotes/get-quote-v3) (Solana support now in production)

  **Schema Fixes:**

  * Fix schema validation warnings for fiatValue, recipientAccount, and account type properties
  * Improve pattern validation for cross-chain operation examples
</Update>

<Update label="2025-07-31" description="v1.2.1" tags={["Improvements"]}>
  ## Improvements

  * Replace `ds:` prefix with `ob:` for [aggregated asset list](/api-reference/assets/list)
</Update>

<Update label="2025-07-17" description="v1.2.0" tags={["Feature"]}>
  ## Solana Support (Beta)

  ### New Features

  #### Multi-Blockchain Support

  * **Added Solana blockchain support** alongside existing EVM chains
  * **Cross-chain operations** between Solana and EVM networks (e.g., SOL → USDC on Arbitrum)
  * **CAIP standards compliance** using CAIP-2 chain identifiers and CAIP-10 account identifiers

  #### New v3 API Endpoints

  * **`POST /v3/quote`** - Generate quotes with multi-account support (EVM + Solana)
  * **`POST /v3/quote/execute`** - Execute quotes across multiple blockchain types
  * **`GET /v3/status/get-execution-status`** - Get execution status with cross-chain transaction details
  * **`GET /v3/status/get-tx-history`** - Retrieve transaction history supporting both EVM and Solana addresses
  * **`GET /v3/balances/aggregated-balance`** - Get aggregated balances across multiple accounts and chains

  #### Enhanced Capabilities

  * **Multi-account architecture** - Single API calls can handle both EVM and Solana accounts
  * **Cross-chain asset aggregation** - Unified view of assets like USDC across EVM and Solana
  * **Solana transaction support** - Native SOL and SPL token operations with proper Base58 signatures
  * **Enhanced examples** - Complete documentation with EVM-only, Solana-only, and cross-chain scenarios

  ### Technical Improvements

  * **CAIP-2 chain identifiers** (e.g., `eip155:1`, `solana:5eykt4UsFv8P8NJdTREpY1vzqKqZKvdp`)
  * **CAIP-10 account identifiers** for recipient addressing
  * **Updated OpenAPI schemas** with new v3 models supporting multi-blockchain operations
  * **Backward compatibility** - All existing v1/v2 endpoints remain unchanged

  ### Supported Operations

  * **Solana native swaps** - SOL ↔ USDC on Solana mainnet
  * **Cross-chain swaps** - SOL → USDC on EVM chains (Arbitrum, etc.)
  * **Multi-chain balance queries** - Single request for balances across EVM and Solana accounts
  * **Transaction tracking** - Unified history view for cross-chain operations
</Update>

<Update label="2025-06-20" description="v1.1.0" tags={["Improvements"]}>
  ## Improvements

  * Add new EXECUTED state to [execution status endpoint](/api-reference/status/get-quote-status)
</Update>