dex_sdk/
flow.rs

1// Copyright (c) 2026 Super Durable, Inc.
2//
3// Licensed under the Super Durable Source License 1.0.
4// You may not use this file except in compliance with the License.
5// See the LICENSE file in the repository root.
6//
7// SPDX-License-Identifier: LicenseRef-Super-Durable-1.0
8
9use crate::{PersistenceSchema, RpcList, StepList, Value, short_type_name};
10
11/// Defines a durable application Flow and its registered API surface.
12///
13/// A Flow owns a typed start input, Step list, persistence schema, and RPC list. Implementations are
14/// registered as owned values in [`crate::Registry`] and shared safely across Worker invocations.
15/// Keep [`Self::flow_type`] and all subordinate names stable while any execution is running.
16///
17/// # Examples
18///
19/// ```
20/// use dex_sdk::{Flow, StepList};
21///
22/// struct OrderFlow;
23///
24/// impl Flow for OrderFlow {
25///     type StartInput = String;
26///
27///     fn flow_type(&self) -> &'static str {
28///         "OrderFlow"
29///     }
30///
31///     fn steps(&self) -> StepList<'_, Self::StartInput> {
32///         StepList::empty()
33///     }
34/// }
35/// ```
36pub trait Flow: Send + Sync + 'static {
37    /// Value accepted by [`crate::Client::start_flow`] and the starting Step.
38    type StartInput: Value;
39
40    /// Returns the stable Flow type sent to Dex.
41    ///
42    /// The default is the final Rust type-name segment.
43    fn flow_type(&self) -> &'static str {
44        short_type_name::<Self>()
45    }
46
47    /// Returns the starting Step and all other Step definitions.
48    ///
49    /// The default is an empty list, which is valid only for Flows driven entirely by RPCs.
50    fn steps(&self) -> StepList<'_, Self::StartInput> {
51        StepList::empty()
52    }
53
54    /// Declares every Attribute and Channel used by this Flow.
55    ///
56    /// The default schema is empty.
57    fn persistence(&self) -> PersistenceSchema {
58        PersistenceSchema::new()
59    }
60
61    /// Binds public RPC names to methods on this Flow implementation.
62    ///
63    /// The default list is empty.
64    fn rpcs(&self) -> RpcList<Self>
65    where
66        Self: Sized,
67    {
68        RpcList::new()
69    }
70}
dex_sdk/flow.rs

dex_sdk/
flow.rs
