GIT-CREDENTIAL(1)

๐Ÿ’– GIT-CREDENTIAL(1) ๐Ÿ’–

okay bestie, welcome to the Git Manual page for git-credential โ€” this is the whole vibe for retrieving and storing user credentials. ๐ŸŽ€


โœจ NAME โœจ

git-credential โ€” retrieve and store user credentials. ๐Ÿ’…


๐ŸŒˆ SYNOPSIS ๐ŸŒˆ

'git credential' (fill|approve|reject|capability)

๐Ÿ’… DESCRIPTION ๐Ÿ’…

okay so Git has an internal interface for storing and retrieving credentials from system-specific helpers, plus prompting the user for usernames and passwords. The git-credential command exposes that interface to scripts โ€” those scripts may want to retrieve, store, or prompt for credentials in the exact same manner as Git. The design of this scriptable interface models the internal C API; peep credential.h for more background on the concepts. ๐Ÿงš

git-credential takes an โ€œactionโ€ option on the command-line (one of fill, approve, or reject) and reads a credential description on stdin (see INPUT/OUTPUT FORMAT). ๐Ÿ‘‘

Hereโ€™s what each action does:

  • fill โ€” git-credential will attempt to add "username" and "password" attributes to the description by reading config files, by contacting any configured credential helpers, or by prompting the user. The username and password attributes of the credential description are then printed to stdout together with the attributes already provided. โœจ
  • approve โ€” git-credential will send the description to any configured credential helpers, which may store the credential for later use. ๐Ÿซถ
  • reject โ€” git-credential will send the description to any configured credential helpers, which may erase any stored credentials matching the description. ๐Ÿ’€
  • capability โ€” git-credential will announce any capabilities it supports to standard output. ๐ŸŒŸ

if the action is approve or reject, no output should be emitted. periodt. ๐Ÿ™ˆ


๐Ÿฆ‹ TYPICAL USE OF GIT CREDENTIAL ๐Ÿฆ‹

an application using git-credential will typically use git credential following these steps, bestie:

  1. generate a credential description based on the context. ๐ŸŽ€

for example, if we want a password for https://example.com/foo.git, we might generate the following credential description (donโ€™t forget the blank line at the end; it tells git credential that the application finished feeding all the information it has):

protocol=https
host=example.com
path=foo.git
  1. ask git-credential to give us a username and password for this description. This is done by running git credential fill, feeding the description from step (1) to its standard input. The complete credential description (including the credential per se, i.e. the login and password) will be produced on standard output, like:
protocol=https
host=example.com
username=bob
password=secr3t

in most cases, this means the attributes given in the input will be repeated in the output, but Git may also modify the credential description, for example by removing the path attribute when the protocol is HTTP(s) and credential.useHttpPath is false. ๐Ÿ˜ญ

if the git credential knew about the password, this step may not have involved the user actually typing this password (the user may have typed a password to unlock the keychain instead, or no user interaction was done if the keychain was already unlocked) before it returned password=secr3t. ๐Ÿ”ฅ

  1. use the credential (e.g., access the URL with the username and password from step (2)), and see if itโ€™s accepted. โญ
  2. report on the success or failure of the password. If the credential allowed the operation to complete successfully, then it can be marked with an "approve" action to tell git credential to reuse it in its next invocation. If the credential was rejected during the operation, use the "reject" action so that git credential will ask for a new password in its next invocation. In either case, git credential should be fed with the credential description obtained from step (2) (which also contains the fields provided in step (1)). ๐Ÿ’œ

โœจ INPUT/OUTPUT FORMAT โœจ

okay so git credential reads and/or writes (depends which action you're running, bestie) credential info on its standard input/output ๐Ÿซถ. And that info can be either the keys it needs to look up login info (host, protocol, path, etc.) or the actual credential data you're trying to get (username/password).

The credential is split into a set of named attributes, one per line, ngl. Every attribute is a key-value pair separated by an = (equals) sign, followed by a newline. ๐Ÿ’…

The rules for what's allowed, fr fr:

  • The key may contain any bytes except =, newline, or NUL.
  • The value may contain any bytes except newline or NUL.
  • A line, including the trailing newline, may not exceed 65535 bytes โ€” that cap exists so implementations can parse efficiently, and yes it's a hard limit ๐Ÿ˜ญ.

Attributes whose keys end with C-style array brackets [] can have multiple values ๐Ÿ’–. Each instance of a multi-valued attribute forms an ordered list of values โ€” the order of the repeated attributes is the order of the values. And an empty multi-valued attribute (key[]=\n) acts to clear any previous entries and reset the list.

In all cases, all bytes are treated as-is โ€” meaning there's no quoting, and you literally cannot transmit a value with a newline or NUL in it ๐Ÿ™ˆ. The list of attributes is terminated by a blank line or end-of-file.

Git understands the following attributes ๐Ÿ‘‡


protocol

The protocol over which the credential will be used (e.g., https).

host

The remote hostname for a network credential. This includes the port number if one was specified (e.g., "example.com:8088").

path

The path with which the credential will be used. E.g., for accessing a remote https repository, this will be the repository's path on the server.

username

The credential's username, if we already have one (e.g., from a URL, the configuration, the user, or from a previously run helper).

password

The credential's password, if we are asking it to be stored.

password_expiry_utc

Generated passwords such as an OAuth access token may have an expiry date ๐ŸŒธ. When reading credentials from helpers, git credential fill ignores expired passwords. Represented as Unix time UTC, seconds since 1970.

oauth_refresh_token

An OAuth refresh token may accompany a password that is an OAuth access token. Helpers must treat this attribute as confidential, just like the password attribute ๐Ÿ”’. Git itself has no special behaviour for this attribute.

url

When this special attribute is read by git credential, the value is parsed as a URL and treated as if its constituent parts were read โ€” so e.g. url=https://example.com would behave as if protocol=https and host=example.com had been provided ๐Ÿ’ซ. This can help callers avoid parsing URLs themselves, iconic behaviour tbh.

Note that specifying a protocol is mandatory, and if the URL doesn't specify a hostname (e.g., "cert:///path/to/file") the credential will contain a hostname attribute whose value is an empty string.

Components which are missing from the URL (e.g., there is no username in the example above) will be left unset.

authtype

This indicates that the authentication scheme in question should be used. Common values for HTTP and HTTPS include basic, bearer, and digest โ€” although the latter is insecure and should not be used ๐Ÿ’€. If credential is used, this may be set to an arbitrary string suitable for the protocol in question (usually HTTP).

This value should not be sent unless the appropriate capability (see below) is provided on input.

credential

The pre-encoded credential, suitable for the protocol in question (usually HTTP). If this key is sent, authtype is mandatory, and username and password are not used. For HTTP, Git concatenates the authtype value and this value with a single space to determine the Authorization header ๐Ÿ”ฅ.

This value should not be sent unless the appropriate capability (see below) is provided on input.

ephemeral

This boolean value indicates, if true, that the value in the credential field should not be saved by the credential helper, because its usefulness is limited in time โณ. For example, an HTTP Digest credential value is computed using a nonce and reusing it will not result in successful authentication. This may also be used for situations with short duration (e.g., 24-hour) credentials. The default value is false.

The credential helper will still be invoked with store or erase so that it can determine whether the operation was successful.

This value should not be sent unless the appropriate capability (see below) is provided on input.

state[]

This value provides an opaque state that will be passed back to this helper if it is called again. Each different credential helper may specify this once. The value should include a prefix unique to the credential helper, and should ignore values that don't match its prefix ๐ŸŽ€.

This value should not be sent unless the appropriate capability (see below) is provided on input.

continue

This is a boolean value which, if enabled, indicates that this authentication is a non-final part of a multistage authentication step ๐Ÿชœ. This is common in protocols such as NTLM and Kerberos, where two rounds of client authentication are required, and setting this flag allows the credential helper to implement the multistage authentication step. This flag should only be sent if a further stage is required; that is, if another round of authentication is expected.

This value should not be sent unless the appropriate capability (see below) is provided on input. This attribute is one-way from a credential helper to pass information to Git (or other programs invoking git credential).

wwwauth[]

When an HTTP response is received by Git that includes one or more WWW-Authenticate authentication headers, these will be passed by Git to credential helpers ๐Ÿ“จ.

Each WWW-Authenticate header value is passed as a multi-valued attribute wwwauth[], where the order of the attributes is the same as they appear in the HTTP response. This attribute is one-way from Git to pass additional information to credential helpers.

capability[]

This signals that Git, or the helper, as appropriate, supports the capability in question โœ…. This can be used to provide better, more specific data as part of the protocol. A capability[] directive must precede any value depending on it, and these directives should be the first item announced in the protocol.

There are two currently supported capabilities, bestie:

  1. authtype โ€” which indicates that the authtype, credential, and ephemeral values are understood.
  2. state โ€” which indicates that the state[] and continue values are understood.

It is not obligatory to use the additional features just because the capability is supported, but they should not be provided without the capability. Periodt.


Unrecognised attributes and capabilities are silently discarded. ๐Ÿซฅ


๐Ÿฆ‹ CAPABILITY INPUT/OUTPUT FORMAT ๐Ÿฆ‹

For git credential capability, the format is slightly different, okay? First, a version 0 announcement is made to indicate the current version of the protocol, and then each capability is announced with a line like capability authtype โœจ. Credential helpers may also implement this format, again with the capability argument. Additional lines may be added in the future; callers should ignore lines which they don't understand.

Because this is a new part of the credential helper protocol, older versions of Git, as well as some credential helpers, may not support it ๐Ÿ˜ฌ. If a non-zero exit status is received, or if the first line doesn't start with the word version and a space, callers should assume that no capabilities are supported.

The intention of this format is to differentiate it from the credential output in an unambiguous way ๐Ÿ’…. It is possible to use very simple credential helpers (e.g., inline shell scripts) which always produce identical output. Using a distinct format allows users to continue to use this syntax without having to worry about correctly implementing capability advertisements or accidentally confusing callers querying for capabilities. Iconic design choice ngl ๐ŸŒˆ.


๐Ÿ‘‘ GIT

Part of the git(1) suite ๐Ÿซถ


that's the whole page bestie, you ate that ๐Ÿ’–โœจ๐ŸŽ€ โ€” this was Git 2.56.0, dated 2026-09-27, and yeah the footer said GIT-CREDENTIAL(1) in case you were wondering ๐ŸŒธ๐Ÿฆ‹

๐Ÿ“ฆ where this page comes from