Specification for Predicate Indexer for Limit Order Predicate

Overview

This specification outlines the requirements for a predicate indexer for a limit order predicate. The indexer will track and index events related to order creation, cancellation, and fulfillment based on the predicate's logic, tests, and scripts.

Predicate Reference

• Predicate: Limit Order Predicate
• Source Code: Limit Order Predicate on GitHub

Test Suite

• Location: Local Tests on GitHub
• Key Tests:
  • create_order
  • cancel_order
  • fulfill_order

Testnet Scripts

• Location: Testnet Scripts on GitHub
• Scripts:
  • cancel_order
  • fulfill_order

Event Indexing

The indexer will be responsible for monitoring and storing the following events:

1. Create Order Event: Triggered when an order is created.
2. Cancel Order Event: Triggered when an order is canceled.
3. Fulfill Order Event: Triggered when an order is fulfilled.

Implementation Details

1. Data Collection: The indexer will listen for events emitted by the limit order predicate on the Fuel Beta 5 testnet.
2. Data Storage: Relevant data from each event will be stored in a structured format, ensuring quick retrieval and query capabilities. This may include order details, transaction identifiers, timestamps, and participant addresses.
3. Script Execution Tracking: For the cancel_order and fulfill_order scripts, the indexer will capture the outcomes and the sequence of actions within each script execution.
4. Event Parsing: Each event type will be parsed to extract and store relevant information, such as order ID, trader address, order size, price, and status changes.
5. Integration with Test Suites: The indexer will be integrated with the local test suite to validate the correctness of indexed data against known outcomes.

Requirements

• Real-Time Indexing: The system should index events in real-time or near-real-time for prompt data availability.
• Scalability: The indexer should be scalable to handle an increasing number of transactions and events without significant performance degradation.
• Reliability: The system should ensure data integrity and consistency, even in cases of network or system failures.
• Query Interface: Provide an API or query interface for retrieving indexed data, supporting queries based on order ID, trader address, and order status.

Testing and Validation

• Local Test Integration: Validate the indexer against local tests for create, cancel, and fulfill orders.
• Testnet Script Results Analysis: Analyze the results of the cancel_order and fulfill_order scripts executed on the testnet to ensure accurate indexing and representation of events.

Output Documentation

• Indexing Results: Document the outcomes and indexed data for both local tests and testnet script executions.
• Discrepancies and Anomalies: Any deviations from expected results should be documented and analyzed for root cause determination.

Future Considerations

• Upgrades and Maintenance: Plan for regular updates and maintenance to accommodate changes in the limit order predicate and the Fuel ecosystem.
• Expansion of Indexed Events: Consider future expansion to include additional event types as the limit order predicate evolves.

Cancel Order script output

maker address = 0x194c4d5d321ea3bc2e87109f4a86520ad60f924998f67007d487d3cc0acc45d2

amount0 = 40000 USDC (0450e4d385cbd2914f74505f18f01587cc4f4ad1fdef4b80cbde2a8155a86d72)
amount1 = 1 BTC (593b117a05f5ea64b39ba1f9bc3fb7e7a791c9be130e28376ad552eacdb3b746)
price = 0 USDC/BTC
predicate root = Bech32Address { hrp: "fuel", hash: 02d8f51b84a8ad850a7d844af62331c16c6cc1068c9303b45879b77ca5a1b2fd }

create order tx: 1192b64a4742d7729652bdb7906f2e454d2c5ae114937e9f1b3c83476fc7039b

cancel order tx: dda0c8a501aeca4acf1c3f61895fbbac0ef5b192f3802cc4cd26c102b4406416

Fulfill Order script output

maker address = 0x194c4d5d321ea3bc2e87109f4a86520ad60f924998f67007d487d3cc0acc45d2

taker address = 0x47010c8ecfeaa888954d7a536131fa962060e28552f3353c06954afdc558410e

amount0 = 40000 USDC (0450e4d385cbd2914f74505f18f01587cc4f4ad1fdef4b80cbde2a8155a86d72)
amount1 = 1 BTC (593b117a05f5ea64b39ba1f9bc3fb7e7a791c9be130e28376ad552eacdb3b746)
price = 0 USDC/BTC
predicate root = Bech32Address { hrp: "fuel", hash: 02d8f51b84a8ad850a7d844af62331c16c6cc1068c9303b45879b77ca5a1b2fd }

create order tx: dc4ec0b49d8e34ef8a56c2bc8af48578445633b233d36de829319f262b1251a4

fulfill order tx: 0b8b0ca86951c1923d5377410a064eda025651e011d9869d04c040fdc3daba4d