technical/http-protocol.html - external/gitster/git-htmldocs - Git at Google

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 <div id="header">
 <h1>HTTP transfer protocols</h1>
 </div>
 <div id="content">
 <div id="preamble">
 <div class="sectionbody">
 <div class="paragraph"><p>Git supports two HTTP based transfer protocols. A "dumb" protocol
 which requires only a standard HTTP server on the server end of the
 connection, and a "smart" protocol which requires a Git aware CGI
 (or server module). This document describes both protocols.</p></div>
 <div class="paragraph"><p>As a design feature smart clients can automatically upgrade "dumb"
 protocol URLs to smart URLs. This permits all users to have the
 same published URL, and the peers automatically select the most
 efficient transport available to them.</p></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_url_format">URL Format</h2>
 <div class="sectionbody">
 <div class="paragraph"><p>URLs for Git repositories accessed by HTTP use the standard HTTP
 URL syntax documented by RFC 1738, so they are of the form:</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>http://&lt;host&gt;:&lt;port&gt;/&lt;path&gt;?&lt;searchpart&gt;</code></pre>
 </div></div>
 <div class="paragraph"><p>Within this documentation the placeholder <code>$GIT_URL</code> will stand for
 the http:// repository URL entered by the end-user.</p></div>
 <div class="paragraph"><p>Servers SHOULD handle all requests to locations matching <code>$GIT_URL</code>, as
 both the "smart" and "dumb" HTTP protocols used by Git operate
 by appending additional path components onto the end of the user
 supplied <code>$GIT_URL</code> string.</p></div>
 <div class="paragraph"><p>An example of a dumb client requesting for a loose object:</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>$GIT_URL: http://example.com:8080/git/repo.git
 URL request: http://example.com:8080/git/repo.git/objects/d0/49f6c27a2244e12041955e262a404c7faba355</code></pre>
 </div></div>
 <div class="paragraph"><p>An example of a smart request to a catch-all gateway:</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>$GIT_URL: http://example.com/daemon.cgi?svc=git&amp;q=
 URL request: http://example.com/daemon.cgi?svc=git&amp;q=/info/refs&amp;service=git-receive-pack</code></pre>
 </div></div>
 <div class="paragraph"><p>An example of a request to a submodule:</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>$GIT_URL: http://example.com/git/repo.git/path/submodule.git
 URL request: http://example.com/git/repo.git/path/submodule.git/info/refs</code></pre>
 </div></div>
 <div class="paragraph"><p>Clients MUST strip a trailing <code>/</code>, if present, from the user supplied
 <code>$GIT_URL</code> string to prevent empty path tokens (<code>//</code>) from appearing
 in any URL sent to a server. Compatible clients MUST expand
 <code>$GIT_URL/info/refs</code> as <code>foo/info/refs</code> and not <code>foo//info/refs</code>.</p></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_authentication">Authentication</h2>
 <div class="sectionbody">
 <div class="paragraph"><p>Standard HTTP authentication is used if authentication is required
 to access a repository, and MAY be configured and enforced by the
 HTTP server software.</p></div>
 <div class="paragraph"><p>Because Git repositories are accessed by standard path components
 server administrators MAY use directory based permissions within
 their HTTP server to control repository access.</p></div>
 <div class="paragraph"><p>Clients SHOULD support Basic authentication as described by RFC 2617.
 Servers SHOULD support Basic authentication by relying upon the
 HTTP server placed in front of the Git server software.</p></div>
 <div class="paragraph"><p>Servers SHOULD NOT require HTTP cookies for the purposes of
 authentication or access control.</p></div>
 <div class="paragraph"><p>Clients and servers MAY support other common forms of HTTP based
 authentication, such as Digest authentication.</p></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_ssl">SSL</h2>
 <div class="sectionbody">
 <div class="paragraph"><p>Clients and servers SHOULD support SSL, particularly to protect
 passwords when relying on Basic HTTP authentication.</p></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_session_state">Session State</h2>
 <div class="sectionbody">
 <div class="paragraph"><p>The Git over HTTP protocol (much like HTTP itself) is stateless
 from the perspective of the HTTP server side. All state MUST be
 retained and managed by the client process. This permits simple
 round-robin load-balancing on the server side, without needing to
 worry about state management.</p></div>
 <div class="paragraph"><p>Clients MUST NOT require state management on the server side in
 order to function correctly.</p></div>
 <div class="paragraph"><p>Servers MUST NOT require HTTP cookies in order to function correctly.
 Clients MAY store and forward HTTP cookies during request processing
 as described by RFC 2616 (HTTP/1.1). Servers SHOULD ignore any
 cookies sent by a client.</p></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_general_request_processing">General Request Processing</h2>
 <div class="sectionbody">
 <div class="paragraph"><p>Except where noted, all standard HTTP behavior SHOULD be assumed
 by both client and server. This includes (but is not necessarily
 limited to):</p></div>
 <div class="paragraph"><p>If there is no repository at <code>$GIT_URL</code>, or the resource pointed to by a
 location matching <code>$GIT_URL</code> does not exist, the server MUST NOT respond
 with <code>200 OK</code> response. A server SHOULD respond with
 <code>404 Not Found</code>, <code>410 Gone</code>, or any other suitable HTTP status code
 which does not imply the resource exists as requested.</p></div>
 <div class="paragraph"><p>If there is a repository at <code>$GIT_URL</code>, but access is not currently
 permitted, the server MUST respond with the <code>403 Forbidden</code> HTTP
 status code.</p></div>
 <div class="paragraph"><p>Servers SHOULD support both HTTP 1.0 and HTTP 1.1.
 Servers SHOULD support chunked encoding for both request and response
 bodies.</p></div>
 <div class="paragraph"><p>Clients SHOULD support both HTTP 1.0 and HTTP 1.1.
 Clients SHOULD support chunked encoding for both request and response
 bodies.</p></div>
 <div class="paragraph"><p>Servers MAY return ETag and/or Last-Modified headers.</p></div>
 <div class="paragraph"><p>Clients MAY revalidate cached entities by including If-Modified-Since
 and/or If-None-Match request headers.</p></div>
 <div class="paragraph"><p>Servers MAY return <code>304 Not Modified</code> if the relevant headers appear
 in the request and the entity has not changed. Clients MUST treat
 <code>304 Not Modified</code> identical to <code>200 OK</code> by reusing the cached entity.</p></div>
 <div class="paragraph"><p>Clients MAY reuse a cached entity without revalidation if the
 Cache-Control and/or Expires header permits caching. Clients and
 servers MUST follow RFC 2616 for cache controls.</p></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_discovering_references">Discovering References</h2>
 <div class="sectionbody">
 <div class="paragraph"><p>All HTTP clients MUST begin either a fetch or a push exchange by
 discovering the references available on the remote repository.</p></div>
 <div class="sect2">
 <h3 id="_dumb_clients">Dumb Clients</h3>
 <div class="paragraph"><p>HTTP clients that only support the "dumb" protocol MUST discover
 references by making a request for the special info/refs file of
 the repository.</p></div>
 <div class="paragraph"><p>Dumb HTTP clients MUST make a <code>GET</code> request to <code>$GIT_URL/info/refs</code>,
 without any search/query parameters.</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>C: GET $GIT_URL/info/refs HTTP/1.0</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>S: 200 OK
 S:
 S: 95dcfa3633004da0049d3d0fa03f80589cbcaf31 refs/heads/maint
 S: d049f6c27a2244e12041955e262a404c7faba355 refs/heads/master
 S: 2cb58b79488a98d2721cea644875a8dd0026b115 refs/tags/v1.0
 S: a3c2e2402b99163d1d59756e5f207ae21cccba4c refs/tags/v1.0^{}</code></pre>
 </div></div>
 <div class="paragraph"><p>The Content-Type of the returned info/refs entity SHOULD be
 <code>text/plain; charset=utf-8</code>, but MAY be any content type.
 Clients MUST NOT attempt to validate the returned Content-Type.
 Dumb servers MUST NOT return a return type starting with
 <code>application/x-git-</code>.</p></div>
 <div class="paragraph"><p>Cache-Control headers MAY be returned to disable caching of the
 returned entity.</p></div>
 <div class="paragraph"><p>When examining the response clients SHOULD only examine the HTTP
 status code. Valid responses are <code>200 OK</code>, or <code>304 Not Modified</code>.</p></div>
 <div class="paragraph"><p>The returned content is a UNIX formatted text file describing
 each ref and its known value. The file SHOULD be sorted by name
 according to the C locale ordering. The file SHOULD NOT include
 the default ref named <code>HEAD</code>.</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>info_refs = *( ref_record )
 ref_record = any_ref / peeled_ref</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>any_ref = obj-id HTAB refname LF
 peeled_ref = obj-id HTAB refname LF
  obj-id HTAB refname "^{}" LF</code></pre>
 </div></div>
 </div>
 <div class="sect2">
 <h3 id="_smart_clients">Smart Clients</h3>
 <div class="paragraph"><p>HTTP clients that support the "smart" protocol (or both the
 "smart" and "dumb" protocols) MUST discover references by making
 a parameterized request for the info/refs file of the repository.</p></div>
 <div class="paragraph"><p>The request MUST contain exactly one query parameter,
 <code>service=$servicename</code>, where <code>$servicename</code> MUST be the service
 name the client wishes to contact to complete the operation.
 The request MUST NOT contain additional query parameters.</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>C: GET $GIT_URL/info/refs?service=git-upload-pack HTTP/1.0</code></pre>
 </div></div>
 <div class="paragraph"><p>dumb server reply:</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>S: 200 OK
 S:
 S: 95dcfa3633004da0049d3d0fa03f80589cbcaf31 refs/heads/maint
 S: d049f6c27a2244e12041955e262a404c7faba355 refs/heads/master
 S: 2cb58b79488a98d2721cea644875a8dd0026b115 refs/tags/v1.0
 S: a3c2e2402b99163d1d59756e5f207ae21cccba4c refs/tags/v1.0^{}</code></pre>
 </div></div>
 <div class="paragraph"><p>smart server reply:</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>S: 200 OK
 S: Content-Type: application/x-git-upload-pack-advertisement
 S: Cache-Control: no-cache
 S:
 S: 001e# service=git-upload-pack\n
 S: 004895dcfa3633004da0049d3d0fa03f80589cbcaf31 refs/heads/maint\0multi_ack\n
 S: 0042d049f6c27a2244e12041955e262a404c7faba355 refs/heads/master\n
 S: 003c2cb58b79488a98d2721cea644875a8dd0026b115 refs/tags/v1.0\n
 S: 003fa3c2e2402b99163d1d59756e5f207ae21cccba4c refs/tags/v1.0^{}\n</code></pre>
 </div></div>
 <div class="sect3">
 <h4 id="_dumb_server_response">Dumb Server Response</h4>
 <div class="paragraph"><p>Dumb servers MUST respond with the dumb server reply format.</p></div>
 <div class="paragraph"><p>See the prior section under dumb clients for a more detailed
 description of the dumb server response.</p></div>
 </div>
 <div class="sect3">
 <h4 id="_smart_server_response">Smart Server Response</h4>
 <div class="paragraph"><p>If the server does not recognize the requested service name, or the
 requested service name has been disabled by the server administrator,
 the server MUST respond with the <code>403 Forbidden</code> HTTP status code.</p></div>
 <div class="paragraph"><p>Otherwise, smart servers MUST respond with the smart server reply
 format for the requested service name.</p></div>
 <div class="paragraph"><p>Cache-Control headers SHOULD be used to disable caching of the
 returned entity.</p></div>
 <div class="paragraph"><p>The Content-Type MUST be <code>application/x-$servicename-advertisement</code>.
 Clients SHOULD fall back to the dumb protocol if another content
 type is returned. When falling back to the dumb protocol clients
 SHOULD NOT make an additional request to <code>$GIT_URL/info/refs</code>, but
 instead SHOULD use the response already in hand. Clients MUST NOT
 continue if they do not support the dumb protocol.</p></div>
 <div class="paragraph"><p>Clients MUST validate the status code is either <code>200 OK</code> or
 <code>304 Not Modified</code>.</p></div>
 <div class="paragraph"><p>Clients MUST validate the first five bytes of the response entity
 matches the regex <code>^[0-9a-f]{4}#</code>. If this test fails, clients
 MUST NOT continue.</p></div>
 <div class="paragraph"><p>Clients MUST parse the entire response as a sequence of pkt-line
 records.</p></div>
 <div class="paragraph"><p>Clients MUST verify the first pkt-line is <code># service=$servicename</code>.
 Servers MUST set $servicename to be the request parameter value.
 Servers SHOULD include an LF at the end of this line.
 Clients MUST ignore an LF at the end of the line.</p></div>
 <div class="paragraph"><p>Servers MUST terminate the response with the magic <code>0000</code> end
 pkt-line marker.</p></div>
 <div class="paragraph"><p>The returned response is a pkt-line stream describing each ref and
 its known value. The stream SHOULD be sorted by name according to
 the C locale ordering. The stream SHOULD include the default ref
 named <code>HEAD</code> as the first ref. The stream MUST include capability
 declarations behind a NUL on the first ref.</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>smart_reply = PKT-LINE("# service=$servicename" LF)
  ref_list
  "0000"
 ref_list = empty_list / non_empty_list</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>empty_list = PKT-LINE(zero-id SP "capabilities^{}" NUL cap-list LF)</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>non_empty_list = PKT-LINE(obj-id SP name NUL cap_list LF)
  *ref_record</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>cap-list = capability *(SP capability)
 capability = 1*(LC_ALPHA / DIGIT / "-" / "_")
 LC_ALPHA = %x61-7A</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>ref_record = any_ref / peeled_ref
 any_ref = PKT-LINE(obj-id SP name LF)
 peeled_ref = PKT-LINE(obj-id SP name LF)
  PKT-LINE(obj-id SP name "^{}" LF</code></pre>
 </div></div>
 </div>
 </div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_smart_service_git_upload_pack">Smart Service git-upload-pack</h2>
 <div class="sectionbody">
 <div class="paragraph"><p>This service reads from the repository pointed to by <code>$GIT_URL</code>.</p></div>
 <div class="paragraph"><p>Clients MUST first perform ref discovery with
 <code>$GIT_URL/info/refs?service=git-upload-pack</code>.</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>C: POST $GIT_URL/git-upload-pack HTTP/1.0
 C: Content-Type: application/x-git-upload-pack-request
 C:
 C: 0032want 0a53e9ddeaddad63ad106860237bbf53411d11a7\n
 C: 0032have 441b40d833fdfa93eb2908e52742248faf0ee993\n
 C: 0000</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>S: 200 OK
 S: Content-Type: application/x-git-upload-pack-result
 S: Cache-Control: no-cache
 S:
 S: ....ACK %s, continue
 S: ....NAK</code></pre>
 </div></div>
 <div class="paragraph"><p>Clients MUST NOT reuse or revalidate a cached response.
 Servers MUST include sufficient Cache-Control headers
 to prevent caching of the response.</p></div>
 <div class="paragraph"><p>Servers SHOULD support all capabilities defined here.</p></div>
 <div class="paragraph"><p>Clients MUST send at least one "want" command in the request body.
 Clients MUST NOT reference an id in a "want" command which did not
 appear in the response obtained through ref discovery unless the
 server advertises capability <code>allow-tip-sha1-in-want</code> or
 <code>allow-reachable-sha1-in-want</code>.</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>compute_request = want_list
  have_list
  request_end
 request_end = "0000" / "done"</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>want_list = PKT-LINE(want NUL cap_list LF)
  *(want_pkt)
 want_pkt = PKT-LINE(want LF)
 want = "want" SP id
 cap_list = *(SP capability) SP</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>have_list = *PKT-LINE("have" SP id LF)</code></pre>
 </div></div>
 <div class="paragraph"><p>TODO: Document this further.</p></div>
 <div class="sect2">
 <h3 id="_the_negotiation_algorithm">The Negotiation Algorithm</h3>
 <div class="paragraph"><p>The computation to select the minimal pack proceeds as follows
 (C = client, S = server):</p></div>
 <div class="paragraph"><p><em>init step:</em></p></div>
 <div class="paragraph"><p>C: Use ref discovery to obtain the advertised refs.</p></div>
 <div class="paragraph"><p>C: Place any object seen into set <code>advertised</code>.</p></div>
 <div class="paragraph"><p>C: Build an empty set, <code>common</code>, to hold the objects that are later
  determined to be on both ends.</p></div>
 <div class="paragraph"><p>C: Build a set, <code>want</code>, of the objects from <code>advertised</code> the client
  wants to fetch, based on what it saw during ref discovery.</p></div>
 <div class="paragraph"><p>C: Start a queue, <code>c_pending</code>, ordered by commit time (popping newest
  first). Add all client refs. When a commit is popped from
  the queue its parents SHOULD be automatically inserted back.
  Commits MUST only enter the queue once.</p></div>
 <div class="paragraph"><p><em>one compute step:</em></p></div>
 <div class="paragraph"><p>C: Send one <code>$GIT_URL/git-upload-pack</code> request:</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>C: 0032want &lt;want #1&gt;...............................
 C: 0032want &lt;want #2&gt;...............................
 ....
 C: 0032have &lt;common #1&gt;.............................
 C: 0032have &lt;common #2&gt;.............................
 ....
 C: 0032have &lt;have #1&gt;...............................
 C: 0032have &lt;have #2&gt;...............................
 ....
 C: 0000</code></pre>
 </div></div>
 <div class="paragraph"><p>The stream is organized into "commands", with each command
 appearing by itself in a pkt-line. Within a command line,
 the text leading up to the first space is the command name,
 and the remainder of the line to the first LF is the value.
 Command lines are terminated with an LF as the last byte of
 the pkt-line value.</p></div>
 <div class="paragraph"><p>Commands MUST appear in the following order, if they appear
 at all in the request stream:</p></div>
 <div class="ulist"><ul>
 <li>
 <p>
 "want"
 </p>
 </li>
 <li>
 <p>
 "have"
 </p>
 </li>
 </ul></div>
 <div class="paragraph"><p>The stream is terminated by a pkt-line flush (<code>0000</code>).</p></div>
 <div class="paragraph"><p>A single "want" or "have" command MUST have one hex formatted
 SHA-1 as its value. Multiple SHA-1s MUST be sent by sending
 multiple commands.</p></div>
 <div class="paragraph"><p>The <code>have</code> list is created by popping the first 32 commits
 from <code>c_pending</code>. Less can be supplied if <code>c_pending</code> empties.</p></div>
 <div class="paragraph"><p>If the client has sent 256 "have" commits and has not yet
 received one of those back from <code>s_common</code>, or the client has
 emptied <code>c_pending</code> it SHOULD include a "done" command to let
 the server know it won&#8217;t proceed:</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>C: 0009done</code></pre>
 </div></div>
 <div class="paragraph"><p>S: Parse the git-upload-pack request:</p></div>
 <div class="paragraph"><p>Verify all objects in <code>want</code> are directly reachable from refs.</p></div>
 <div class="paragraph"><p>The server MAY walk backwards through history or through
 the reflog to permit slightly stale requests.</p></div>
 <div class="paragraph"><p>If no "want" objects are received, send an error:
 TODO: Define error if no "want" lines are requested.</p></div>
 <div class="paragraph"><p>If any "want" object is not reachable, send an error:
 TODO: Define error if an invalid "want" is requested.</p></div>
 <div class="paragraph"><p>Create an empty list, <code>s_common</code>.</p></div>
 <div class="paragraph"><p>If "have" was sent:</p></div>
 <div class="paragraph"><p>Loop through the objects in the order supplied by the client.</p></div>
 <div class="paragraph"><p>For each object, if the server has the object reachable from
 a ref, add it to <code>s_common</code>. If a commit is added to <code>s_common</code>,
 do not add any ancestors, even if they also appear in <code>have</code>.</p></div>
 <div class="paragraph"><p>S: Send the git-upload-pack response:</p></div>
 <div class="paragraph"><p>If the server has found a closed set of objects to pack or the
 request ends with "done", it replies with the pack.
 TODO: Document the pack based response</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>S: PACK...</code></pre>
 </div></div>
 <div class="paragraph"><p>The returned stream is the side-band-64k protocol supported
 by the git-upload-pack service, and the pack is embedded into
 stream 1. Progress messages from the server side MAY appear
 in stream 2.</p></div>
 <div class="paragraph"><p>Here a "closed set of objects" is defined to have at least
 one path from every "want" to at least one "common" object.</p></div>
 <div class="paragraph"><p>If the server needs more information, it replies with a
 status continue response:
 TODO: Document the non-pack response</p></div>
 <div class="paragraph"><p>C: Parse the upload-pack response:
  TODO: Document parsing response</p></div>
 <div class="paragraph"><p><em>Do another compute step.</em></p></div>
 </div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_smart_service_git_receive_pack">Smart Service git-receive-pack</h2>
 <div class="sectionbody">
 <div class="paragraph"><p>This service reads from the repository pointed to by <code>$GIT_URL</code>.</p></div>
 <div class="paragraph"><p>Clients MUST first perform ref discovery with
 <code>$GIT_URL/info/refs?service=git-receive-pack</code>.</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>C: POST $GIT_URL/git-receive-pack HTTP/1.0
 C: Content-Type: application/x-git-receive-pack-request
 C:
 C: ....0a53e9ddeaddad63ad106860237bbf53411d11a7 441b40d833fdfa93eb2908e52742248faf0ee993 refs/heads/maint\0 report-status
 C: 0000
 C: PACK....</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>S: 200 OK
 S: Content-Type: application/x-git-receive-pack-result
 S: Cache-Control: no-cache
 S:
 S: ....</code></pre>
 </div></div>
 <div class="paragraph"><p>Clients MUST NOT reuse or revalidate a cached response.
 Servers MUST include sufficient Cache-Control headers
 to prevent caching of the response.</p></div>
 <div class="paragraph"><p>Servers SHOULD support all capabilities defined here.</p></div>
 <div class="paragraph"><p>Clients MUST send at least one command in the request body.
 Within the command portion of the request body clients SHOULD send
 the id obtained through ref discovery as old_id.</p></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>update_request = command_list
  "PACK" &lt;binary data&gt;</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>command_list = PKT-LINE(command NUL cap_list LF)
  *(command_pkt)
 command_pkt = PKT-LINE(command LF)
 cap_list = *(SP capability) SP</code></pre>
 </div></div>
 <div class="literalblock">
 <div class="content">
 <pre><code>command = create / delete / update
 create = zero-id SP new_id SP name
 delete = old_id SP zero-id SP name
 update = old_id SP new_id SP name</code></pre>
 </div></div>
 <div class="paragraph"><p>TODO: Document this further.</p></div>
 </div>
 </div>
 <div class="sect1">
 <h2 id="_references">References</h2>
 <div class="sectionbody">
 <div class="paragraph"><p><a href="http://www.ietf.org/rfc/rfc1738.txt">RFC 1738: Uniform Resource Locators (URL)</a>
 <a href="http://www.ietf.org/rfc/rfc2616.txt">RFC 2616: Hypertext Transfer Protocol&#8201;&#8212;&#8201;HTTP/1.1</a>
 link:technical/pack-protocol.html
 link:technical/protocol-capabilities.html</p></div>
 </div>
 </div>
 </div>
 <div id="footnotes"><hr /></div>
 <div id="footer">
 <div id="footer-text">
 Last updated 2015-06-01 13:36:36 PDT
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