Across allows users to send tokens from one chain to another almost immediately without having to wait for the rollup’s challenge period. Liquidity providers provide liquidity and relayers handle the fills and in return they charge a transfer fee (supply-side fees).

Across is a cross-chain token bridge for L2s and rollups. Across was founded by Hart Lambur and launched in 2021.

ACX tokenholders own and govern the protocol. They currently don’t take a cut of the total transfer fees paid by the users (revenue). Across’ investors include Hack VC, Placeholder and Blockchain Capital.

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Across

# Across Active users (weekly) Methodology

## 1. Overview

Weekly Active Users (WAU) for Across protocol measures the number of unique users who completed cross-chain bridge transfers within any 7-day rolling window. This metric answers the business question: "How many distinct users are actively using Across bridges on a weekly basis?" The calculation uses HyperLogLog algorithms for memory-efficient approximate counting of unique users across multiple chains and provides dimensional breakdowns by chain, user type, and product.

## 2. Data sources

The calculation relies on the following blockchain data sources:

- **Cross-chain bridge events**: Parsed `FilledRelay` events from Across V2 SpokePool contracts deployed on Ethereum, Arbitrum, Base, BSC, Linea, Optimism, Polygon, Scroll, Worldchain, and zkSync Era
- **Legacy bridge events**: Parsed `DepositRelayed` events from Across V1 BridgePool contracts on Ethereum  
- **Event parameters**: Recipient addresses extracted from event parameters, with different parameter structures across protocol versions (direct `recipient` field vs nested `relayExecutionInfo.updatedRecipient`)
- **Transaction metadata**: Block timestamps and transaction hashes for temporal analysis
- **Chain metadata**: Chain identifiers for multi-chain analysis

## 3. Step-by-step calculation

### Component A: User extraction from bridge events
- **Purpose**: Identifies unique user addresses from completed cross-chain bridge transfers
- **Logic**: Extracts recipient addresses from bridge completion events across all supported chains. For Across V1, uses the `l1Recipient` field from `DepositRelayed` events. For Across V2, uses either the `recipient` field from `FilledRelay` events or the `updatedRecipient` field from `FilledV3Relay` events depending on the contract version. All users are classified as "Trader" type since they represent bridge transfer recipients
- **Key fields**: `block_timestamp` for temporal analysis, `user_address` for unique user identification, `chain` for multi-chain breakdown, `user_type` set to "Trader", and `transaction_hash` for deduplication

### Component B: Daily active user aggregation
- **Purpose**: Creates daily snapshots of unique active users using HyperLogLog sketches
- **Logic**: Groups bridge events by day, chain, user type, and product dimensions. Converts user addresses into HyperLogLog sketches with 15-bit precision for memory-efficient approximate counting. Truncates timestamps to daily granularity and applies chain availability filters to ensure data quality
- **Key fields**: `timestamp` truncated to day, `chain` identifier, `user_type` classification, `product_id` (null for Across), and `hll` containing the HyperLogLog sketch of unique users

### Component C: Rolling window creation
- **Purpose**: Generates 7-day rolling windows for weekly active user calculation
- **Logic**: Creates a complete date spine covering the entire analysis period to ensure no missing days. For each day, generates a 7-day window by creating timestamps for the current day plus the previous 6 days. Joins this window with the daily HyperLogLog data to collect all user activity within each 7-day period
- **Key fields**: `timestamp` for the window end date, `joinday` for individual days within the window, and `hll` sketches from matching daily data

### Component D: Weekly active user calculation by dimensions
- **Purpose**: Calculates unique weekly active users across different dimensional breakdowns
- **Logic**: Merges HyperLogLog sketches across each 7-day window to count unique users. Creates four separate breakdowns: overall project-level WAU, WAU by individual chain, WAU by user type, and WAU by product. Uses HyperLogLog merge operations to combine sketches and extract final unique counts while avoiding double-counting users who appear multiple times within the window
- **Key fields**: `user_wau` containing the final unique count, `dimensions` indicating the breakdown type, and dimension-specific fields (`chain_id`, `user_type`, `product_id`)

### Final aggregation
- **Combining components**: Unions all dimensional breakdowns (project-level, by chain, by user type, by product) into a single result set with standardized schema
- **Currency conversion**: Not applicable for user count metrics
- **Time aggregation**: Uses 7-day rolling windows where each day represents the count of unique users active within that day and the previous 6 days
- **Final calculation**: The final `user_wau` value represents the approximate count of unique user addresses that completed at least one bridge transfer within any 7-day rolling period, calculated using HyperLogLog merge operations across daily sketches

*This methodology was automatically generated by Token Terminal's methodology analyzer.*

Unique revenue-generating users over a rolling 7-day window.

AcrossACX

Active users (weekly)

Active users (weekly)

Competitive landscape

Chain breakdown