Get Application Logs
Retrieving logs of your Spin applications at runtime is crucial to understand runtime behavior and for gathering insights.
Retrieving Logs of Your Application
Use the spin aka logs command, to retrieve logs of your Spin application deployed to Fermyon Wasm Functions.
By default, this command provides logs for the application your workspace is linked to. If your workspace isn’t linked to an application, you can either specify the application name using the --app-name flag for a one-time connection or run spin aka link to link your workspace to an application running on Fermyon Wasm Functions.
$ spin aka logs --app-name hello-fermyon-wasm-functions
The spin aka logs command, will print all log messages to stdout as shown here:
2025-01-16 13:31:46 [hello-fermyon-wasm-functions] 2025/01/16 13:31:36 INFO GET https://11077e3b-d632-4df3-921f-f7ebefb9aaca.aka.fermyon.tech/hello: Handled by handle_hello func
2025-01-16 13:31:48 [hello-fermyon-wasm-functions] 2025/01/16 13:31:47 INFO POST https://11077e3b-d632-4df3-921f-f7ebefb9aaca.aka.fermyon.tech/greet: Handled by handle_greet func
2025-01-16 13:31:48 [hello-fermyon-wasm-functions] 2025/01/16 13:31:47 WARN Greet invoked with invalid payload. Will respond with HTTP 400
2025-01-16 13:32:04 [hello-fermyon-wasm-functions] 2025/01/16 13:31:56 INFO POST https://11077e3b-d632-4df3-921f-f7ebefb9aaca.aka.fermyon.tech/greet: Handled by handle_greet func
The log messages shown above have been generated using the log/slog package by a Spin application written in Go. Technically, everything your Spin application writes to stdout and stderr will be captured by Fermyon Wasm Functions and made accessible via the spin aka logs command.