> For the complete documentation index, see [llms.txt](https://docs.ecotone.tech/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ecotone.tech/modelling/event-sourcing.md).

# Event Sourcing

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Works with: **Laravel**, **Symfony**, and **Standalone PHP**
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## The Problem

You store the current state of your entities, but not how they got there. When a customer disputes a charge, you can't answer "what exactly happened?" Rebuilding read models after a schema change means writing migration scripts by hand. Auditors ask for a complete trail of changes and you piece it together from application logs.

## How Ecotone Solves It

Ecotone provides **Event Sourcing** as a first-class feature. Instead of storing current state, you store the sequence of events that led to it. Rebuild any view of the data by replaying events. Get a complete, immutable audit trail automatically. Works with **Postgres**, **MySQL**, and **MariaDB** for event storage, with projections that can write to any storage you choose.

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**Building durable workflows on top of event sourcing?** Event-sourced sagas (`#[EventSourcingSaga]`) record every state transition of a long-running process — order fulfillment, payouts, KYC, multi-step onboarding — as queryable events in your own database. Crashes, deploys, and restarts: the saga rehydrates by replaying its events and continues from exactly where it left off. See [Durable Execution in PHP](/solutions/durable-execution.md) for the three workflow shapes Ecotone supports.
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***

Read more in the following chapters.

## Materials

### Demo implementation

* [Implementing Event Sourcing Aggregates](https://github.com/ecotoneframework/quickstart-examples/tree/main/EventSourcing)
* [Emitting Events from Projections](https://github.com/ecotoneframework/quickstart-examples/tree/main/EmittingEventsFromProjection)
* [Working directly with Event Sourcing Aggregates](https://github.com/ecotoneframework/quickstart-examples/tree/main/WorkingWithAggregateDirectly)

### Links

* [Starting with Event Sourcing in PHP](https://blog.ecotone.tech/starting-with-event-sourcing-in-php/) \[Article]
* [Implementing Event Sourcing Application in 15 minutes](https://blog.ecotone.tech/implementing-event-sourcing-php-application-in-15-minutes/) \[Article]


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