Install fuego via go get:

go get

Or use one of the precompiled binaries (untested) from the latest release.



You'll need a Service Account key file to be able to access your project's firestore database. To create a service account private key file, if you don't have one, go to your firebase project console, then Project settings and then click on the Service accounts tab and generate a new private key.

Once you have your service account key file, fuego will be able to find it using one of the following options:

  1. Use the --credentials flag everytime you execute fuego, i.e.:
fuego --credentials ./my-account-service-private-key.json get mycollection mydocumentid


  1. Via the GOOGLE_APPLICATION_CREDENTIALS environment variable:
export GOOGLE_APPLICATION_CREDENTIALS=./my-account-service-private-key.json
fuego get mycollection mydocumentid

List collections

fuego collections

Will return the list of projet's collections.

Writing and reading data

You can add new documents, using JSON:

fuego add people '{"name": "sergio", "age": 41}'
# Rv7ZfnLQWprdXuulqMdf <- fuego prints the ID of the newly created document

Of fetch them, using the ID:

fuego get people Rv7ZfnLQWprdXuulqMdf
# {
#    "age": 41,
#    "name": "sergio"
# }

You can also update an existing document:

fuego set people Rv7ZfnLQWprdXuulqMdf '{"name": "sergio", "age": 42}' # It's my birthday!

In both add and set commands, the document argument can be either a json string (if it starts with the character '{') or a path to a json file, i.e.:

fuego add animals ./dog.json

A note on types

fuego read and write commands are constrained by JSON data types: string, number, object, array and boolean, which don't cover all of firestore data types.

When writing data, you can make fuego treat all strings that match the rfc3339 datetime format as firestore timestamps, using the --timestamp (or --ts) flag. For example:

fuego add --ts dates '{"randomdate": "2012-11-01T22:08:41+00:00"}'

will add a new document whose field named "randomdate" is a timestamp and not a string.


Let's explain queries by example. First, we'll create a collection of physics nobel laureates,

fuego add nobel '{"name": "Arthur Ashkin", "year": 2018, "birthplace": {"country":"USA", "city": "New York"}}'
fuego add nobel '{"name": "Gerard Mourou", "year": 2018, "birthplace": {"country":"FRA", "city": "Albertville"}}'
fuego add nobel '{"name": "Donna Strickland", "year": 2018, "birthplace": {"country":"CAN", "city": "Guelph"}}'
fuego add nobel '{"name": "Rainer Weiss", "year": 2017, "birthplace": {"country":"DEU", "city": "Berlin"}}'
fuego add nobel '{"name": "Kip Thorne", "year": 2017, "birthplace": {"country":"USA", "city": "Logan"}}'
fuego add nobel '{"name": "Barry Barish", "year": 2017, "birthplace": {"country":"USA", "city": "Omaha"}}'
fuego add nobel '{"name": "David Thouless", "year": 2016, "birthplace": {"country":"GBR", "city": "Bearsden"}}'

We can query the full collection:

fuego query nobel
# Prints all our nobel laureates like this:
# [
#    {
#        "CreateTime": "2019-02-26T02:39:45.293936Z",
#        "Data": {
#            "birthplace": {
#                "city": "Bearsden",
#                "country": "GBR"
#            },
#            "name": "David Thouless",
#            "year": 2016
#        },
#        "ID": "BJseSVoBatOOt8gcwZWx",
#        "ReadTime": "2019-02-26T02:55:19.419627Z",
#        "UpdateTime": "2019-02-26T02:39:45.293936Z"
#    },
# .... etc

Which will fetch and display the documents in the collection, unfiltered. By default, fuego will fetch only 100 documents. You can change the limit using the --limit flag.

You can also order the results using the --orderby and --orderdir flags. For example, to sort our nobel laureates by country of origin, in ascending order:

fuego query --orderby --orderdir ASC nobel

You can add filters, using the firestore supported operators (>, <, >=, <= and ==). You can combine several filters in a single query. For example, to get the 2018 nobel laureates from the USA:

fuego query nobel ' == "USA"' 'year == 2018'

which will print:

        "CreateTime": "2019-02-26T02:14:02.692077Z",
        "Data": {
            "birthplace": {
                "city": "New York",
                "country": "USA"
            "name": "Arthur Ashkin",
            "year": 2018
        "ID": "glHCUu7EZ3gkuDaVlXqv",
        "ReadTime": "2019-02-26T03:00:15.576398Z",
        "UpdateTime": "2019-02-26T02:59:55.889775Z"

Let's say we want to find the least recent nobel from the USA, we can write the following query:

fuego query --limit 1 --orderby year --orderdir ASC nobel " == 'USA'" 

oops, we get the following error from the server, because our query needs an index to work:

rpc error: code = FailedPrecondition desc = The query requires an index. 
You can create it here:

After creating the index, we re-run the query and now we obtain:

        "CreateTime": "2019-02-26T02:39:44.458647Z",
        "Data": {
            "birthplace": {
                "city": "Omaha",
                "country": "USA"
            "name": "Barry Barish",
            "year": 2017
        "ID": "ainH3nkOA2xusEBON2An",
        "ReadTime": "2019-02-26T03:12:07.156643Z",
        "UpdateTime": "2019-02-26T02:39:44.458647Z"

Value and field path types in filters

I our previous examples, all the segments of the path part of a filter contained alphanumeric or the _ character and did not start with a number. When this conditions are met, they can be written unquoted. Otherwise, they need to be unquoted.

fuego query weirdcollection 'really."    ".strage." but valid ".fieldname == "even blank keys are valid"'

As for values, numeric, string, boolean and timestamp values are supported in filters. Examples of queries:

"age >= 34", "name == 'paul'", "married == true", and "birthday == 1977-06-28T04:00:00Z"

Note that timestamps values should use the RFC3339 format and should not be quoted. Boolean values are represented by the unquoted true and false strings.

Selecting specific fields

Use the --select flag to explicitely ask for the specific fields you want to be retrieved (you can define many using several --select)

fuego query --select name --select year --limit 1 --orderby year --orderdir ASC nobel " == 'USA'" 

Pagination of query results

There are two ways to page through query results.

First you can use the firestore pagination parameters to manually page through results. Combining --limit with the flags --startat, --startafter, --endat, and --endbefore, which all accept the ID of a document.

Second you can use the --batch parameter. This will cause fuego to do the pagination internally. This is helpful for very big queries which hit the firestore query timeout (about a minute). Very likely you will have to increase the --limit parameter from its default.


Releases are managed by goreleaser.


  1. export GITHUB_TOKEN=your_token
  2. Update version in main.go (i.e v0.1.0)
  3. Update (set version)
  4. Commit changes
  5. git tag -a v0.1.0 -m "First release"
  6. git push origin v0.1.0
  7. goreleaser (options: --rm-dist --release-notes=)


The tests are located in test as a shuint2 shell script. It is using the firestore emulator provided by gcloud. You also need to have the commandline tool jq installed.

To execute the tests go into the tests directory and run:

./tests -- nameoffirsttest nameofsecondtest