> ## Documentation Index
> Fetch the complete documentation index at: https://docs.base44.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Get backend function logs
> This API is in beta. Endpoints, fields, and behavior may still change, so avoid depending on it in production.
Returns recent log lines from one of the app's backend functions, newest first.
A line is anything the function wrote to the console, plus the errors it didn't catch. The lines hold whatever the function logged, so they can include data about the app's users.
By default you get up to 500 lines from the last 7 days. Set `since` and `until` to pick a different window, `level` to keep one severity, and `limit` for fewer lines. Logs are kept for a limited time, so a window far in the past can come back empty.
To page back, send the `time` of the oldest line you have, plus one millisecond, as `until`, and drop the lines you already have. Several lines can share a millisecond, and this keeps you from skipping any.
A function that doesn't exist, or that has never run, returns an empty list rather than an error.
Some older apps whose functions haven't moved to Base44's current function runtime can window and filter their lines differently.
This is limited to 60 requests a minute per app for each workspace's personal API keys, so every key in a workspace shares one allowance. Some workspaces have a different limit.
This endpoint accepts a personal API key, including a read-only one, from anyone with access to the app, viewers included. Workspace API keys are not authorized for it.
## OpenAPI
````yaml /developers/references/app-management/app-management-openapi.json get /api/apps/{app_id}/functions-mgmt/{function_name}/logs
openapi: 3.1.0
info:
title: Base44 App Management API
version: 1.0.0
servers:
- url: https://app.base44.com
security:
- PersonalAccessTokenAuth: []
paths:
/api/apps/{app_id}/functions-mgmt/{function_name}/logs:
get:
summary: Get backend function logs
description: >-
This API is in beta. Endpoints, fields, and behavior may still
change, so avoid depending on it in production.
Returns recent log lines from one of the app's backend functions, newest
first.
A line is anything the function wrote to the console, plus the errors it
didn't catch. The lines hold whatever the function logged, so they can
include data about the app's users.
By default you get up to 500 lines from the last 7 days. Set `since` and
`until` to pick a different window, `level` to keep one severity, and
`limit` for fewer lines. Logs are kept for a limited time, so a window
far in the past can come back empty.
To page back, send the `time` of the oldest line you have, plus one
millisecond, as `until`, and drop the lines you already have. Several
lines can share a millisecond, and this keeps you from skipping any.
A function that doesn't exist, or that has never run, returns an empty
list rather than an error.
Some older apps whose functions haven't moved to Base44's current
function runtime can window and filter their lines differently.
This is limited to 60 requests a minute per app for each workspace's
personal API keys, so every key in a workspace shares one allowance.
Some workspaces have a different limit.
This endpoint accepts a personal API key, including a read-only
one, from anyone with access to the app, viewers included. Workspace API
keys are not authorized for it.
operationId: >-
get_backend_functions_logs_api_apps__app_id__functions_mgmt__function_name__logs_get
parameters:
- name: function_name
in: path
required: true
schema:
type: string
description: >-
Name of the backend function, without a file extension. Nested
functions have slashes in their name, and you send those as they
are.
title: Function Name
description: >-
Name of the backend function, without a file extension. Nested
functions have slashes in their name, and you send those as they
are.
example: sendWelcomeEmail
- name: app_id
in: path
required: true
schema:
type: string
description: ID of the app the function belongs to.
title: App Id
description: ID of the app the function belongs to.
example: 6820f3a4e7b91d003c45a1f2
- name: env
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: >-
Whose traffic to show. `prod` returns lines from the deployment
serving the published app, and `preview` returns lines from the
builder's preview. Leave it out for every line from the function's
latest deployment. Any other value is ignored.
title: Env
description: >-
Whose traffic to show. `prod` returns lines from the deployment
serving the published app, and `preview` returns lines from the
builder's preview. Leave it out for every line from the function's
latest deployment. Any other value is ignored.
example: prod
- name: since
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: >-
Start of the window, as an ISO 8601 timestamp. A timestamp without
an offset is read as UTC. Defaults to 7 days before `until`.
title: Since
description: >-
Start of the window, as an ISO 8601 timestamp. A timestamp without
an offset is read as UTC. Defaults to 7 days before `until`.
example: '2026-01-14T00:00:00Z'
- name: until
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: >-
End of the window, as an ISO 8601 timestamp. A timestamp without
an offset is read as UTC. Defaults to now.
title: Until
description: >-
End of the window, as an ISO 8601 timestamp. A timestamp without an
offset is read as UTC. Defaults to now.
example: '2026-01-15T09:23:41Z'
- name: level
in: query
required: false
schema:
anyOf:
- type: string
- type: 'null'
description: >-
Keep only lines at this severity. Send `debug`, `info`, `warn`, or
`error`, and `warning` is read as `warn`.
title: Level
description: >-
Keep only lines at this severity. Send `debug`, `info`, `warn`, or
`error`, and `warning` is read as `warn`.
example: error
- name: limit
in: query
required: false
schema:
anyOf:
- type: integer
- type: 'null'
description: >-
Maximum number of lines to return, from 1 to 500. Defaults to 500,
and a larger value is treated as 500.
title: Limit
description: >-
Maximum number of lines to return, from 1 to 500. Defaults to 500,
and a larger value is treated as 500.
example: 50
responses:
'200':
description: The log lines, newest first.
content:
application/json:
schema:
type: array
items:
$ref: '#/components/schemas/FunctionLogLine'
title: >-
Response 200 Get Backend Functions Logs Api Apps App Id
Functions Mgmt Function Name Logs Get
'400':
description: >-
`since` or `until` isn't a valid timestamp, `since` isn't before
`until`, or `level` isn't one of the accepted values.
'401':
description: Missing or invalid credentials.
'403':
description: You don't have access to this app, or you used a workspace API key.
'404':
description: App not found.
'422':
description: '`limit` isn''t a whole number.'
'429':
description: >-
Too many requests for this app in the last minute from personal API
keys in your workspace.
components:
schemas:
FunctionLogLine:
properties:
time:
type: string
title: Time
description: When the line was logged, as a UTC timestamp in ISO 8601 format.
example: '2026-01-15T09:23:41.482000+00:00'
level:
type: string
title: Level
description: Severity of the line, such as `info`, `warn`, or `error`.
example: info
message:
type: string
title: Message
description: >-
What the function wrote. An uncaught error carries its name, message
and stack trace. Each invocation also gets a line of its own with
the request method and response status, like `POST → 200`.
example: Sent welcome email to jane@acme.com
type: object
required:
- time
- level
- message
title: FunctionLogLine
description: One line a backend function logged.
securitySchemes:
PersonalAccessTokenAuth:
type: http
scheme: bearer
description: 'Personal access token, sent as `Authorization: Bearer `.'
````