Feature

Idempotency

Safe retries without duplicate side effects.

20 providers 476 APIs 13 declared variants

Idempotency keys or exactly-once semantics let clients retry after a timeout without double-charging or double-writing. Essential wherever operations move money or state.

20 API providers on the APIs.io network offer idempotency. The highest-rated are Stripe, Amazon Neptune, Knock, Raygun, Novu.

Providers

Ranked by API Evangelist rating — Exemplar and Strong are expanded by default.

Exemplar 5 Complete, well-documented, and agent-ready
Stripe Online payment processing for internet businesses. Stripe is a suite of payment APIs that powers commerce f... 159 APIs 84.7 Amazon Neptune Amazon Neptune is a fast, reliable, fully managed graph database service that makes it easy to build and ru... 29 APIs 73.3 Knock Knock is notifications infrastructure as a service — a product and customer messaging platform you use to p... 35 APIs 72.2 Raygun Raygun is an application monitoring platform that combines Crash Reporting, Real User Monitoring (RUM), and... 15 APIs 68.7 Novu Novu is the open-source notification infrastructure for developers. A single REST API and workflow engine r... 19 APIs 66.4
Strong 6 Solid coverage with minor gaps
Civitai Civitai is the largest open community for Stable Diffusion, SDXL, Flux, and video AI models — hosting over ... 12 APIs 62.4 Flutterwave Flutterwave is a pan-African payment infrastructure company providing the rails for businesses to accept, s... 19 APIs 62.0 Deel Deel is a global workforce platform combining payroll, Employer of Record (EOR), independent contractor man... 39 APIs 61.3 CockroachDB CockroachDB is a distributed SQL database with strong consistency, PostgreSQL compatibility, and a managed ... 26 APIs 58.7 Justworks Justworks is a New York City-based Professional Employer Organization (PEO) and small-business HR platform.... 11 APIs 57.9 Couchbase Couchbase is a distributed, document-oriented NoSQL cloud database platform that combines the flexibility o... 54 APIs 56.9
Developing 6 Usable, with meaningful gaps to close
Apache Kafka Apache Kafka is an open-source distributed event streaming platform used by thousands of companies for high... 12 APIs 53.9 Apache Ignite Apache Ignite is a distributed database for mission-critical high-velocity applications requiring in-memory... 15 APIs 53.7 Apache Iceberg Apache Iceberg is an open table format for large analytic datasets that provides ACID transactions, schema ... 5 APIs 53.1 Apache Geode Apache Geode is an in-memory data management platform that provides real-time, consistent access to data-in... 5 APIs 47.3 Apache Hive Apache Hive is a data warehouse software that facilitates reading, writing, and managing large datasets res... 4 APIs 46.8 Apache Flink Apache Flink is a framework and distributed processing engine for stateful computations over unbounded and ... 10 APIs 45.6
Thin 2 Limited public surface area
Apache RocketMQ Apache RocketMQ is a distributed messaging and streaming platform with low latency, high performance, and r... 4 APIs 41.0 Apache Derby Apache Derby is an open-source relational database implemented entirely in Java, formerly governed by the A... 1 API 39.8
Emerging 1 Early or largely undocumented
Ecologi Ecologi is a Bristol, UK climate action platform and B Corp founded in 2019 that lets individuals and busin... 2 APIs 20.8

What Providers Actually Declared

This feature is a canonical term. These are the free-text strings providers wrote in their own apis.yml that map onto it.

ACID TransactionsACID transactions across regionsCrash Reporting — error detection, deduplication into error groups, full stack-trace and breadcrumb contextDeductions endpoints (list types, list, create, update, cancel) with per-row operation_id idempotencyExactly-Once SemanticsHTTPS-only webhook endpoints with retry on non-2xx; idempotency keyed on `(workflowId, status, timestamp)`Idempotency + RateLimit HeadersIdempotency keys on POST/PATCH via UUID v4 with 24-hour response cacheIdempotency via `X-Idempotency-Key` (UUID) returned on retry with `X-Idempotency-Cache-HitIdempotency-Key header support for safe automatic retriesIdempotency-Key support for safe retriesIdempotent requests via Idempotency-KeyMulti-document ACID transactions

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