lfmedit

Last.fm subscribers have the ability to edit their scrobbles, i.e. to update the title, artist, album or album artist of a scrobble. This can only be done using Last.fm website UI, at the time of writing there is no Last.fm API method for editing scrobbles.

lfmedit.sh and lfmbatchedit.sh allow sending scrobble edit requests from the command line, which makes it possible to automate the editing process.

These scripts were created to support way of working based on an Last.fm scrobble export. The idea is to have the export data under version control, introduce local changes using dedicated tooling and finally apply these changes on Last.fm end using lfmbatchedit.sh.

Using the scripts

Requirements

• bash
• curl
• jq
• bc
• Last.fm subscription

Authentication

Only an authenticated Last.fm subscriber is authorized to edit scrobbles. The scripts mimic the behavior of the website sending edit requests to Last.fm backend, so they require the same set of authentication tokens:

• Last.fm username
• session ID
• CSRF token

The username is not a problem, but obtaining the other two tokens is not as straightforward. Session ID and CSRF token are created at login and stored in browser cookies. It's possible to get them using the browser developer console (F12 in Firefox or Chrome). Copy the values of cookies sessionid and csrftoken, and set the relevant variables in lfmedit/auth_tokens in your user's config directory. See the sample file for details.

Usage examples

Change the title and artist of a single scrobble

$ ./lfmedit.sh -V -u 1616948298 -t "Damnation" -a "Nine Inch Nails"
INF: requestScrobbleEdit(): This is the edit that will be applied:
-1616948298    [Castle of the Damned]    Trent Reznor    Quake    Trent Reznor
+1616948298    Damnation    Nine Inch Nails    Quake    Nine Inch Nails
Proceed? (uppercase Y to confirm, anything else to abort): Y
INF: verifyScrobbleEdit(): verification passed! Scrobble edited successfully

The parameter -u is mandatory because Last.fm seems to be using the Unix timestamp as scrobble ID. Apart from the timestamp, it's only required to set options corresponding to fields you want to change - in this example only the title and artist are modified, the album stays the same. Note that the album artist (last column) was automatically changed to match the new track artist.

It is possible to remove information (e.g. passing -b "" will remove album field from the scrobble), but it's not allowed to remove artist or title.

Edit several scrobbles

The input file of lfmbatchedit.sh is a tab-separated file where each line consists of eight fields: the first four are the timestamp, track title, artist name and album title of the old scrobble. The following four are the same data corresponding to the updated scrobble:

$ cat scrobbles.tsv
1616948633    [Necropolis]    Trent Reznor    Quake    1616948633    Focus    Nine Inch Nails    Quake
1616949021    [Ziggurat Vertigo]    Trent Reznor    Quake    1616949021    Falling    Nine Inch Nails    Quake
1616949233    [Gloom Keep]    Trent Reznor    Quake    1616949233    The Reaction    Nine Inch Nails    Quake

Note that the same timestamp is specified twice. This is on purpose: it allows checking if the tool that created the .tsv file produced consistent data.

$ ./lfmbatchedit.sh -V -Y scrobbles.tsv
INF: processFiles(): processing "scrobbles.tsv"

INF: applyChangesFrom(): editing scrobble 1 of 3
INF: requestScrobbleEdit(): This is the edit that will be applied:
-1616948633    [Necropolis]    Trent Reznor    Quake    Trent Reznor
+1616948633    Focus    Nine Inch Nails    Quake    Nine Inch Nails
INF: verifyScrobbleEdit(): verification passed! Scrobble edited successfully

INF: applyChangesFrom(): editing scrobble 2 of 3
INF: requestScrobbleEdit(): This is the edit that will be applied:
-1616949021    [Ziggurat Vertigo]    Trent Reznor    Quake    Trent Reznor
+1616949021    Falling    Nine Inch Nails    Quake    Nine Inch Nails
INF: verifyScrobbleEdit(): verification passed! Scrobble edited successfully

INF: applyChangesFrom(): editing scrobble 3 of 3
INF: requestScrobbleEdit(): This is the edit that will be applied:
-1616949233    [Gloom Keep]    Trent Reznor    Quake    Trent Reznor
+1616949233    The Reaction    Nine Inch Nails    Quake    Nine Inch Nails
INF: verifyScrobbleEdit(): verification passed! Scrobble edited successfully

INF: applyChangesFrom(): Processed 3 scrobbles from "scrobbles.tsv" in 11 seconds.

Successful and failed edits are logged to appropriate files. The switch -Y disables asking for edit confirmation. Run the scripts with -h switch to get the full list of supported options.

Known issues / limitations

• lfmedit.sh is not very useful, in a way it's just a development version of lfmbatchedit.sh
• One of the mandatory parameters of scrobble edit request is the original album artist. It is not possible to get that piece of information from Last.fm API. The scripts try to make an assumption, but there is no guarantee it will be correct. If lfmedit.sh makes a wrong assumption which causes an edit to fail, it's possible to override it using -Z command line option.
• lfmbatchedit.sh currently does not support -Z option.
• Edit verification is not very reliable - I've seen both false positives and false negatives in my testing. For this reason verification is disabled by default. It can be enabled using -V option.

Further development

I consider current implementation feature-complete.

This was supposed to be a quick-and-dirty proof of concept, and this is the reason it was initially written in Bash. As the handling of errors and edge cases grew more complex, I realised this needs to be rewritten in a different programming language. For this reason I was reluctant to spend more time on the Bash implementation. But now that there is no real hope of making the editing process any faster because of throttling on Last.fm end, rewriting this code does not make much sense.

The edit rate has been significantly improved in v2.0.0, and I'm not sure what else could be be done to make it faster.

If any bugs are reported I'll look into fixing them.