GITCREDENTIALS(7) Git Manual GITCREDENTIALS(7)

NAME

gitcredentials - Providing usernames and passwords to Git

SYNOPSIS

git config credential.https://example.com.username myusername
git config credential.helper "$helper $options"

DESCRIPTION

Git will sometimes need credentials from the user in order to perform
operations; for example, it may need to ask for a username and
password in order to access a remote repository over HTTP. Some
remotes accept a personal access token or OAuth access token as a
password. This manual describes the mechanisms Git uses to request
these credentials, as well as some features to avoid inputting these
credentials repeatedly.

REQUESTING CREDENTIALS

Without any credential helpers defined, Git will try the following
strategies to ask the user for usernames and passwords:

1. If the GIT_ASKPASS environment variable is set, the program
specified by the variable is invoked. A suitable prompt is
provided to the program on the command line, and the user's input
is read from its standard output.

2. Otherwise, if the core.askPass configuration variable is set, its
value is used as above.

3. Otherwise, if the SSH_ASKPASS environment variable is set, its
value is used as above.

4. Otherwise, the user is prompted on the terminal.

AVOIDING REPETITION

It can be cumbersome to input the same credentials over and over. Git
provides two methods to reduce this annoyance:

1. Static configuration of usernames for a given authentication
context.

2. Credential helpers to cache or store passwords, or to interact
with a system password wallet or keychain.

The first is simple and appropriate if you do not have secure storage
available for a password. It is generally configured by adding this
to your config:

[credential "https://example.com"]
username = me

Credential helpers, on the other hand, are external programs from
which Git can request both usernames and passwords; they typically
interface with secure storage provided by the OS or other programs.
Alternatively, a credential-generating helper might generate
credentials for certain servers via some API.

To use a helper, you must first select one to use. Git currently
includes the following helpers:

cache
Cache credentials in memory for a short period of time. See git-
credential-cache(1) for details.

store
Store credentials indefinitely on disk. See git-credential-
store(1) for details.

You may also have third-party helpers installed; search for
credential-* in the output of git help -a, and consult the
documentation of individual helpers. Once you have selected a helper,
you can tell Git to use it by putting its name into the
credential.helper variable.

1. Find a helper.

$ git help -a | grep credential-
credential-foo

2. Read its description.

$ git help credential-foo

3. Tell Git to use it.

$ git config --global credential.helper foo

Available helpers

The community maintains a comprehensive list of Git credential
helpers at https://git-scm.com/doc/credential-helpers.

OAuth

An alternative to inputting passwords or personal access tokens is to
use an OAuth credential helper. Initial authentication opens a
browser window to the host. Subsequent authentication happens in the
background. Many popular Git hosts support OAuth.

CREDENTIAL CONTEXTS

Git considers each credential to have a context defined by a URL.
This context is used to look up context-specific configuration, and
is passed to any helpers, which may use it as an index into secure
storage.

For instance, imagine we are accessing https://example.com/foo.git.
When Git looks into a config file to see if a section matches this
context, it will consider the two a match if the context is a
more-specific subset of the pattern in the config file. For example,
if you have this in your config file:

[credential "https://example.com"]
username = foo

then we will match: both protocols are the same, both hosts are the
same, and the "pattern" URL does not care about the path component at
all. However, this context would not match:

[credential "https://kernel.org"]
username = foo

because the hostnames differ. Nor would it match foo.example.com; Git
compares hostnames exactly, without considering whether two hosts are
part of the same domain. Likewise, a config entry for
http://example.com would not match: Git compares the protocols
exactly. However, you may use wildcards in the domain name and other
pattern matching techniques as with the http.<URL>.* options.

If the "pattern" URL does include a path component, then this too
must match exactly: the context https://example.com/bar/baz.git will
match a config entry for https://example.com/bar/baz.git (in addition
to matching the config entry for https://example.com) but will not
match a config entry for https://example.com/bar.

CONFIGURATION OPTIONS

Options for a credential context can be configured either in
credential.* (which applies to all credentials), or
credential.<URL>.*, where <URL> matches the context as described
above.

The following options are available in either location:

helper
The name of an external credential helper, and any associated
options. If the helper name is not an absolute path, then the
string git credential- is prepended. The resulting string is
executed by the shell (so, for example, setting this to foo
--option=bar will execute git credential-foo --option=bar via the
shell. See the manual of specific helpers for examples of their
use.

If there are multiple instances of the credential.helper
configuration variable, each helper will be tried in turn, and
may provide a username, password, or nothing. Once Git has
acquired both a username and a non-expired password, no more
helpers will be tried.

If credential.helper is configured to the empty string, this
resets the helper list to empty (so you may override a helper set
by a lower-priority config file by configuring the empty-string
helper, followed by whatever set of helpers you would like).

username
A default username, if one is not provided in the URL.

useHttpPath
By default, Git does not consider the "path" component of an http
URL to be worth matching via external helpers. This means that a
credential stored for https://example.com/foo.git will also be
used for https://example.com/bar.git. If you do want to
distinguish these cases, set this option to true.

CUSTOM HELPERS

You can write your own custom helpers to interface with any system in
which you keep credentials.

Credential helpers are programs executed by Git to fetch or save
credentials from and to long-term storage (where "long-term" is
simply longer than a single Git process; e.g., credentials may be
stored in-memory for a few minutes, or indefinitely on disk).

Each helper is specified by a single string in the configuration
variable credential.helper (and others, see git-config(1)). The
string is transformed by Git into a command to be executed using
these rules:

1. If the helper string begins with "!", it is considered a shell
snippet, and everything after the "!" becomes the command.

2. Otherwise, if the helper string begins with an absolute path, the
verbatim helper string becomes the command.

3. Otherwise, the string "git credential-" is prepended to the
helper string, and the result becomes the command.

The resulting command then has an "operation" argument appended to it
(see below for details), and the result is executed by the shell.

Here are some example specifications:

# run "git credential-foo"
[credential]
helper = foo

# same as above, but pass an argument to the helper
[credential]
helper = "foo --bar=baz"

# the arguments are parsed by the shell, so use shell
# quoting if necessary
[credential]
helper = "foo --bar='whitespace arg'"

# store helper (discouraged) with custom location for the db file;
# use `--file ~/.git-secret.txt`, rather than `--file=~/.git-secret.txt`,
# to allow the shell to expand tilde to the home directory.
[credential]
helper = "store --file ~/.git-secret.txt"

# you can also use an absolute path, which will not use the git wrapper
[credential]
helper = "/path/to/my/helper --with-arguments"

# or you can specify your own shell snippet
[credential "https://example.com"]
username = your_user
helper = "!f() { test \"$1\" = get && echo \"password=$(cat $HOME/.secret)\"; }; f"

Generally speaking, rule (3) above is the simplest for users to
specify. Authors of credential helpers should make an effort to
assist their users by naming their program "git-credential-$NAME",
and putting it in the $PATH or $GIT_EXEC_PATH during installation,
which will allow a user to enable it with git config
credential.helper $NAME.

When a helper is executed, it will have one "operation" argument
appended to its command line, which is one of:

get
Return a matching credential, if any exists.

store
Store the credential, if applicable to the helper.

erase
Remove matching credentials, if any, from the helper's storage.

The details of the credential will be provided on the helper's stdin
stream. The exact format is the same as the input/output format of
the git credential plumbing command (see the section INPUT/OUTPUT
FORMAT in git-credential(1) for a detailed specification).

For a get operation, the helper should produce a list of attributes
on stdout in the same format (see git-credential(1) for common
attributes). A helper is free to produce a subset, or even no values
at all if it has nothing useful to provide. Any provided attributes
will overwrite those already known about by Git's credential
subsystem. Unrecognised attributes are silently discarded.

While it is possible to override all attributes, well behaving
helpers should refrain from doing so for any attribute other than
username and password.

If a helper outputs a quit attribute with a value of true or 1, no
further helpers will be consulted, nor will the user be prompted (if
no credential has been provided, the operation will then fail).

Similarly, no more helpers will be consulted once both username and
password had been provided.

For a store or erase operation, the helper's output is ignored.

If a helper fails to perform the requested operation or needs to
notify the user of a potential issue, it may write to stderr.

If it does not support the requested operation (e.g., a read-only
store or generator), it should silently ignore the request.

If a helper receives any other operation, it should silently ignore
the request. This leaves room for future operations to be added
(older helpers will just ignore the new requests).

GIT

Part of the git(1) suite

Git 2.48.1 2025-01-13 GITCREDENTIALS(7)