Python middleware lifecycle

The order of middleware lifecycle hooks is as follows:

1. transform_input
2. before_memoization
3. after_memoization
4. before_execution
5. after_execution
6. transform_output
7. before_response

All of these functions may be called multiple times in a single function run. For example, if your function has 2 steps then all of the hooks will run 3 times (once for each step and once for the function).

Additionally, there are two hooks when sending events:

1. before_send_events
2. after_send_events

Hook reference

transform_input

Called when receiving a request from Inngest and before running any functions. Commonly used to mutate data sent by Inngest, like decryption.

• ctx (Context): ctx argument passed to Inngest functions.

• function (Function): Inngest function object.

• steps (StepMemos): Memoized step data.

before_memoization

Called before checking memoized step data.

after_memoization

Called after exhausting memoized step data.

before_execution

Called before executing "new code". For example, before_execution is called after returning the last memoized step data, since function-level code after that step is "new".

after_execution

Called after executing "new code".

transform_output

Called after a step or function returns. Commonly used to mutate data before sending it back to Inngest, like encryption.

• result (TransformOutputResult): Only set if there's an error.Step or function output. Since None is a valid output, always call the has_output method before accessing the output.Step or function output. Since None is a valid output, always call the has_output method before accessing the output.Step ID.Step type enum. Useful in very rare cases.Step options. Useful in very rare cases.

before_response

Called before sending a response back to Inngest.

before_send_events

Called before sending events to Inngest.

• events (list[Event]): Events to send.

after_send_events

Called after sending events to Inngest.

• result (SendEventsResult): Error string if an error occurred.Event IDs.