How do I get the "sha" parameter from GitHub API without downloading the whole file?

Question

I have been trying to update a file in a GitHub repository by using GitHub API while having only a path to that file. My plan was first, get the file contents like described here: https://developer.github.com/v3/repos/contents/ , and then use the "sha" field to "update a file".

It worked fine just as described in the answer here How to find a Github file 's SHA blob .

However, using GET /repos/:owner/:repo/contents/:path , downloads the whole file, as a field in the returned JSON, which is inefficient. So, my question is: is there a way to get just the "sha" field without downloading the entire file?

Does this answer your question? [How to find a Github file 's SHA blob](https://stackoverflow.com/questions/20207594/how-to-find-a-github-file-s-sha-blob) — Jeff Puckett, Aug 12 '20 at 15:55

nulltoken · Answer 1 · 2014-10-05T15:48:31.760

You could leverage the <rev>:<path> extended SHA-1 syntax to retrieve some meta data about the Blob from its parent Tree.

For instance, provided you work with the libgit2/libgit2sharp repository, and you'd like to retrieve the sha of the file Lib/MoQ/Moq.license.txt from the master branch:

Leverage the GitHub Trees API to retrieve the content of the Tree matching the Lib/MoQ parent directory
Retrieve from the returned Json payload the sha of the blob which path is Moq.license.txt
Make sure to url encode the the <rev>:<path> segment as it contains forward slashes

In brief:

Syntax: GET /repos/<owner>/<repo>/git/trees/url_encode(<branch_name>:<parent_path>)
Example: https://api.github.com/repos/libgit2/libgit2sharp/git/trees/master:Lib%2FMoQ

The example link above will return the following payload

{
  "sha": "2f2c87728225f9cbb6e2d8c5997b6031e72ddca4",
  "url": "https://api.github.com/repos/libgit2/libgit2sharp/git/trees/2f2c87728225f9cbb6e2d8c5997b6031e72ddca4",
  "tree": [
    {
      "path": "Moq.dll",
      "mode": "100644",
      "type": "blob",
      "sha": "bdd4235f215541017a9f37b6155f18e309573838",
      "size": 659968,
      "url": "https://api.github.com/repos/libgit2/libgit2sharp/git/blobs/bdd4235f215541017a9f37b6155f18e309573838"
    },
    {
      "path": "Moq.license.txt",
      "mode": "100644",
      "type": "blob",
      "sha": "c9216ccba318292d76fd308f232e7871bbbe77be",
      "size": 1748,
      "url": "https://api.github.com/repos/libgit2/libgit2sharp/git/blobs/c9216ccba318292d76fd308f232e7871bbbe77be"
    },
    {
      "path": "Moq.xml",
      "mode": "100644",
      "type": "blob",
      "sha": "160c1b5165fd967f4c79bc6043f0cc2ec28710d8",
      "size": 314572,
      "url": "https://api.github.com/repos/libgit2/libgit2sharp/git/blobs/160c1b5165fd967f4c79bc6043f0cc2ec28710d8"
    }
  ],
  "truncated": false
}

Can this be used to get the sha for a file/directory in a GitHub private repo? — Nick Fernandez, Dec 18 '17 at 17:11
I'm lost trying to do this. If my file is at the root, should I have "trees/master:" ? I tried all the reasonable options and I still get 'not found' — Marco Servetto, May 31 '21 at 22:17

score 1 · Answer 2 · answered Oct 27 '21 at 12:17

https://github.com/api/v3/repos/(organization-name)/(repo-name)/git/trees/(branch-name):(parent-folder-path) send a Get request to this end-point and u will get an array of json objects which contains the sha's of all files inside the parent folder and from there u just manage to extract the sha you need you can test it using postman or insomnia and good luck

score -1 · Answer 3 · answered Jan 02 '18 at 18:25

-1

Or do a:

GET /repos/:owner/:repo/contents/:path

on the path to the file and then pick out the sha from the returned data.

answered Jan 02 '18 at 18:25

aaa

7
1

Do you have an example? – Alex Feb 14 '19 at 10:59
9

This [only works](https://developer.github.com/v3/repos/contents/#get-contents) if the file content is under 1MB – smac89 Nov 03 '19 at 00:00

score -1 · Answer 4 · answered Feb 22 '21 at 20:40

-1

Do a HEAD request instead of a GET. It returns the sha as the Etag header.

answered Feb 22 '21 at 20:40

Mark Melville

783
8
13

1

An `ETag` header is only returned if the file is smaller than 1MB. – danvk Jun 17 '21 at 13:59

How do I get the "sha" parameter from GitHub API without downloading the whole file?

4 Answers4

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