# Advanced Topics
Paperless offers a couple features that automate certain tasks and make your life easier.
## Matching tags, correspondents, document types, and storage paths {#matching}
Paperless will compare the matching algorithms defined by every tag, correspondent, document type, and storage path in your database to see if they apply to the text in a document. In other words, if you define a tag called Home Utility that had a match property of bc hydro and a matching_algorithm of Exact, Paperless will automatically tag your newly-consumed document with your Home Utility tag so long as the text bc hydro appears in the body of the document somewhere.
The matching logic is quite powerful. It supports searching the text of your document with different algorithms, and as such, some experimentation may be necessary to get things right.
In order to have a tag, correspondent, document type, or storage path assigned automatically to newly consumed documents, assign a match and matching algorithm using the web interface. These settings define when to assign tags, correspondents, document types, and storage paths to documents.
The following algorithms are available:
None: No matching will be performed.
Any: Looks for any occurrence of any word provided in match in the PDF. If you define the match as Bank1 Bank2, it will match documents containing either of these terms.
All: Requires that every word provided appears in the PDF, albeit not in the order provided.
Exact: Matches only if the match appears exactly as provided (i.e. preserve ordering) in the PDF.
Regular expression: Parses the match as a regular expression and tries to find a match within the document.
Fuzzy match: I don’t know. Look at the source.
Auto: Tries to automatically match new documents. This does not require you to set a match. See the notes below.
When using the _any_ or _all_ matching algorithms, you can search for terms that consist of multiple words by enclosing them in double quotes. For example, defining a match text of “Bank of America” BofA using the _any_ algorithm, will match documents that contain either “Bank of America” or “BofA”, but will not match documents containing “Bank of South America”.
Then just save your tag, correspondent, document type, or storage path and run another document through the consumer. Once complete, you should see the newly-created document, automatically tagged with the appropriate data.
### Automatic matching {#automatic-matching}
Paperless-ngx comes with a new matching algorithm called _Auto_. This matching algorithm tries to assign tags, correspondents, document types, and storage paths to your documents based on how you have already assigned these on existing documents. It uses a neural network under the hood.
If, for example, all your bank statements of your account 123 at the Bank of America are tagged with the tag “bofa123” and the matching algorithm of this tag is set to _Auto_, this neural network will examine your documents and automatically learn when to assign this tag.
Paperless tries to hide much of the involved complexity with this approach. However, there are a couple caveats you need to keep in mind when using this feature:
Changes to your documents are not immediately reflected by the matching algorithm. The neural network needs to be _trained_ on your documents after changes. Paperless periodically (default: once each hour) checks for changes and does this automatically for you.
The Auto matching algorithm only takes documents into account which are NOT placed in your inbox (i.e. have any inbox tags assigned to them). This ensures that the neural network only learns from documents which you have correctly tagged before.
The matching algorithm can only work if there is a correlation between the tag, correspondent, document type, or storage path and the document itself. Your bank statements usually contain your bank account number and the name of the bank, so this works reasonably well, However, tags such as “TODO” cannot be automatically assigned.
The matching algorithm needs a reasonable number of documents to identify when to assign tags, correspondents, storage paths, and types. If one out of a thousand documents has the correspondent “Very obscure web shop I bought something five years ago”, it will probably not assign this correspondent automatically if you buy something from them again. The more documents, the better.
Paperless also needs a reasonable amount of negative examples to decide when not to assign a certain tag, correspondent, document type, or storage path. This will usually be the case as you start filling up paperless with documents. Example: If all your documents are either from “Webshop” and “Bank”, paperless will assign one of these correspondents to ANY new document, if both are set to automatic matching.
## Hooking into the consumption process {#consume-hooks}
Sometimes you may want to do something arbitrary whenever a document is consumed. Rather than try to predict what you may want to do, Paperless lets you execute scripts of your own choosing just before or after a document is consumed using a couple simple hooks.
Just write a script, put it somewhere that Paperless can read & execute, and then put the path to that script in paperless.conf or docker-compose.env with the variable name of either PAPERLESS_PRE_CONSUME_SCRIPT or PAPERLESS_POST_CONSUME_SCRIPT.
!!! info
These scripts are executed in a blocking process, which means that if a script takes a long time to run, it can significantly slow down your document consumption flow. If you want things to run asynchronously, you’ll have to fork the process in your script and exit.
### Pre-consumption script {#pre-consume-script}
Executed after the consumer sees a new document in the consumption folder, but before any processing of the document is performed. This script can access the following relevant environment variables set:
!!! note
Pre-consume scripts which modify the document should only change the DOCUMENT_WORKING_PATH file or a second consume task may be triggered, leading to failures as two tasks work on the same document path
A simple but common example for this would be creating a simple script like this:
/usr/local/bin/ocr-pdf
`bash
#!/usr/bin/env bash
pdf2pdfocr.py -i ${DOCUMENT_WORKING_PATH}
`
/etc/paperless.conf
`bash
...
PAPERLESS_PRE_CONSUME_SCRIPT="/usr/local/bin/ocr-pdf"
...
`
This will pass the path to the document about to be consumed to /usr/local/bin/ocr-pdf, which will in turn call [pdf2pdfocr.py](https://github.com/LeoFCardoso/pdf2pdfocr) on your document, which will then overwrite the file with an OCR’d version of the file and exit. At which point, the consumption process will begin with the newly modified file.
The script’s stdout and stderr will be logged line by line to the webserver log, along with the exit code of the script.
### Post-consumption script {#post-consume-script}
Executed after the consumer has successfully processed a document and has moved it into paperless. It receives the following environment variables:
The script can be in any language, A simple shell script example:
`bash title="post-consumption-example"
--8<-- "./scripts/post-consumption-example.sh"
`
!!! note
The post consumption script cannot cancel the consumption process.
!!! warning
The post consumption script should not modify the document files directly
The script’s stdout and stderr will be logged line by line to the webserver log, along with the exit code of the script.
### Docker {#docker-consume-hooks}
To hook into the consumption process when using Docker, you will need to pass the scripts into the container via a host mount in your docker-compose.yml.
Assuming you have /home/paperless-ngx/scripts/post-consumption-example.sh as a script which you’d like to run.
You can pass that script into the consumer container via a host mount:
… volumes:
… - /home/paperless-ngx/scripts:/path/in/container/scripts/ # (1)!
- environment: # (3)!
… PAPERLESS_POST_CONSUME_SCRIPT: /path/in/container/scripts/post-consumption-example.sh # (2)!
…
The external scripts directory is mounted to a location inside the container.
The internal location of the script is used to set the script to run
This can also be set in docker-compose.env
Troubleshooting:
Monitor the docker-compose log cd ~/paperless-ngx; docker-compose logs -f
Check your script’s permission e.g. in case of permission error sudo chmod 755 post-consumption-example.sh
Pipe your scripts’s output to a log file e.g. echo “${DOCUMENT_ID}” | tee –append /usr/src/paperless/scripts/post-consumption-example.log
## File name handling {#file-name-handling}
By default, paperless stores your documents in the media directory and renames them using the identifier which it has assigned to each document. You will end up getting files like 0000123.pdf in your media directory. This isn’t necessarily a bad thing, because you normally don’t have to access these files manually. However, if you wish to name your files differently, you can do that by adjusting the PAPERLESS_FILENAME_FORMAT configuration option. Paperless adds the correct file extension e.g. .pdf, .jpg automatically.
This variable allows you to configure the filename (folders are allowed) using placeholders. For example, configuring this to
`bash
PAPERLESS_FILENAME_FORMAT={created_year}/{correspondent}/{title}
`
will create a directory structure as follows:
``` 2019/
- My bank/
Statement January.pdf Statement February.pdf
- 2020/
- My bank/
Statement January.pdf Letter.pdf Letter_01.pdf
- Shoe store/
My new shoes.pdf
!!! warning
Do not manually move your files in the media folder. Paperless remembers the last filename a document was stored as. If you do rename a file, paperless will report your files as missing and won’t be able to find them.
Paperless provides the following placeholders within filenames:
{asn}: The archive serial number of the document, or “none”.
{correspondent}: The name of the correspondent, or “none”.
{document_type}: The name of the document type, or “none”.
{tag_list}: A comma separated list of all tags assigned to the document.
{title}: The title of the document.
{created}: The full date (ISO format) the document was created.
{created_year}: Year created only, formatted as the year with century.
{created_year_short}: Year created only, formatted as the year without century, zero padded.
{created_month}: Month created only (number 01-12).
{created_month_name}: Month created name, as per locale
{created_month_name_short}: Month created abbreviated name, as per locale
{created_day}: Day created only (number 01-31).
{added}: The full date (ISO format) the document was added to paperless.
{added_year}: Year added only.
{added_year_short}: Year added only, formatted as the year without century, zero padded.
{added_month}: Month added only (number 01-12).
{added_month_name}: Month added name, as per locale
{added_month_name_short}: Month added abbreviated name, as per locale
{added_day}: Day added only (number 01-31).
{owner_username}: Username of document owner, if any, or “none”
{original_name}: Document original filename, minus the extension, if any, or “none”
Paperless will try to conserve the information from your database as much as possible. However, some characters that you can use in document titles and correspondent names (such as : / and a couple more) are not allowed in filenames and will be replaced with dashes.
If paperless detects that two documents share the same filename, paperless will automatically append _01, _02, etc to the filename. This happens if all the placeholders in a filename evaluate to the same value.
!!! tip
You can affect how empty placeholders are treated by changing the following setting to true.
` PAPERLESS_FILENAME_FORMAT_REMOVE_NONE=True `Doing this results in all empty placeholders resolving to “” instead of “none” as stated above. Spaces before empty placeholders are removed as well, empty directories are omitted.
!!! tip
Paperless checks the filename of a document whenever it is saved. Therefore, you need to update the filenames of your documents and move them after altering this setting by invoking the [document renamer](/administration#renamer).
!!! warning
Make absolutely sure you get the spelling of the placeholders right, or else paperless will use the default naming scheme instead.
!!! caution
As of now, you could totally tell paperless to store your files anywhere outside the media directory by setting
` PAPERLESS_FILENAME_FORMAT=../../my/custom/location/{title} `However, keep in mind that inside docker, if files get stored outside of the predefined volumes, they will be lost after a restart of paperless.
!!! warning
When file naming handling, in particular when using {tag_list}, you may run into the limits of your operating system’s maximum path lengths. Files will retain the previous path instead and the issue logged.
## Storage paths
One of the best things in Paperless is that you can not only access the documents via the web interface, but also via the file system.
When a single storage layout is not sufficient for your use case, storage paths come to the rescue. Storage paths allow you to configure more precisely where each document is stored in the file system.
Each storage path is a PAPERLESS_FILENAME_FORMAT and follows the rules described above
Each document is assigned a storage path using the matching algorithms described above, but can be overwritten at any time
For example, you could define the following two storage paths:
Normal communications are put into a folder structure sorted by year/correspondent
Communications with insurance companies are stored in a flat structure with longer file names, but containing the full date of the correspondence.
`
By Year = {created_year}/{correspondent}/{title}
Insurances = Insurances/{correspondent}/{created_year}-{created_month}-{created_day} {title}
`
If you then map these storage paths to the documents, you might get the following result. For simplicity, By Year defines the same structure as in the previous example above.
- My bank/
Statement January.pdf Statement February.pdf
- Insurances/ # Insurances
- Healthcare 123/
2022-01-01 Statement January.pdf 2022-02-02 Letter.pdf 2022-02-03 Letter.pdf
- Dental 456/
2021-12-01 New Conditions.pdf
!!! tip
Defining a storage path is optional. If no storage path is defined for a document, the global PAPERLESS_FILENAME_FORMAT is applied.
## Celery Monitoring {#celery-monitoring}
The monitoring tool [Flower](https://flower.readthedocs.io/en/latest/index.html) can be used to view more detailed information about the health of the celery workers used for asynchronous tasks. This includes details on currently running, queued and completed tasks, timing and more. Flower can also be used with Prometheus, as it exports metrics. For details on its capabilities, refer to the Flower documentation.
To configure Flower further, create a flowerconfig.py and place it into the src/paperless directory. For a Docker installation, you can use volumes to accomplish this:
# … webserver:
- ports:
5555:5555 # (2)!
# … volumes:
/path/to/my/flowerconfig.py:/usr/src/paperless/src/paperless/flowerconfig.py:ro # (1)!
Note the :ro tag means the file will be mounted as read only.
flower runs by default on port 5555, but this can be configured
## Custom Container Initialization
The Docker image includes the ability to run custom user scripts during startup. This could be utilized for installing additional tools or Python packages, for example. Scripts are expected to be shell scripts.
To utilize this, mount a folder containing your scripts to the custom initialization directory, /custom-cont-init.d and place scripts you wish to run inside. For security, the folder must be owned by root and should have permissions of a=rx. Additionally, scripts must only be writable by root.
Your scripts will be run directly before the webserver completes startup. Scripts will be run by the root user. If you would like to switch users, the utility gosu is available and preferred over sudo.
This is an advanced functionality with which you could break functionality or lose data. If you experience issues, please disable any custom scripts and try again before reporting an issue.
For example, using Docker Compose:
# … webserver:
# … volumes:
/path/to/my/scripts:/custom-cont-init.d:ro # (1)!
Note the :ro tag means the folder will be mounted as read only. This is for extra security against changes
## MySQL Caveats {#mysql-caveats}
### Case Sensitivity
The database interface does not provide a method to configure a MySQL database to be case sensitive. This would prevent a user from creating a tag Name and NAME as they are considered the same.
Per Django documentation, to enable this requires manual intervention. To enable case sensetive tables, you can execute the following command against each table:
ALTER TABLE <table_name> CONVERT TO CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;
You can also set the default for new tables (this does NOT affect existing tables) with:
ALTER DATABASE <db_name> CHARACTER SET utf8mb4 COLLATE utf8mb4_bin;
!!! warning
Using mariadb version 10.4+ is recommended. Using the utf8mb3 character set on an older system may fix issues that can arise while setting up Paperless-ngx but utf8mb3 can cause issues with consumption (where utf8mb4 does not).
## Barcodes {#barcodes}
Paperless is able to utilize barcodes for automatically preforming some tasks.
At this time, the library utilized for detection of bacodes supports the following types:
AN-13/UPC-A
UPC-E
EAN-8
Code 128
Code 93
Code 39
Codabar
Interleaved 2 of 5
QR Code
SQ Code
You may check for updates on the [zbar library homepage](https://github.com/mchehab/zbar). For usage in Paperless, the type of barcode does not matter, only the contents of it.
For how to enable barcode usage, see [the configuration](/configuration#barcodes). The two settings may be enabled independently, but do have interactions as explained below.
### Document Splitting
When enabled, Paperless will look for a barcode with the configured value and create a new document starting from the next page. The page with the barcode on it will _not_ be retained. It is expected to be a page existing only for triggering the split.
### Archive Serial Number Assignment
When enabled, the value of the barcode (as an integer) will be used to set the document’s archive serial number, allowing quick reference back to the original, paper document.
If document splitting via barcode is also enabled, documents will be split when an ASN barcode is located. However, differing from the splitting, the page with the barcode _will_ be retained. This allows application of a barcode to any page, including one which holds data to keep in the document.