Request–Response Model

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Pronunciation

[ri-kwest re-sponss mod-uhl]

Analogy

Like ordering food at a restaurant by placing an order and waiting for the waiter to bring your meal.

Definition

A communication pattern where a client sends a request to a service and waits synchronously for a response, commonly used in API and interactions.

Key Points Intro

The request–response model underpins synchronous data retrieval in integrations.

Key Points

Synchronous flow: client blocks until response arrives

Structured messages: predefined request and response schemas

Timeout handling: manages latency and retries

Error codes: standardized failure reasons for diagnostics

Example

A emits an event to request market data, then reads the returned value in a follow-up once the service responds.

Technical Deep Dive

Clients emit RequestData events, relayers listen via WebSocket, call external REST or services, then invoke contract callbacks with signed responses. Schemas defined in Protobuf or JSON ensure compatibility. Contracts include fallback oracles and retry logic.

Security Warning

Blocking dependencies can stall contract and increase costs if the external service is slow or unavailable.

Caveat

Synchronous dependencies add complexity and unpredictability to workflows.

Related Terms

Pull Model Oracle

Push Model Oracle

gRPC

Blockchain & Cryptocurrency Glossary

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