message.coffee

###############################################################################
#
#    CoCalc: Collaborative Calculation in the Cloud
#
#    Copyright (C) 2016, Sagemath Inc.
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License as published by
#    the Free Software Foundation, either version 3 of the License, or
#    (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
###############################################################################

###
#
# Library for working with JSON messages for Salvus.
#
# We use functions to work with messages to ensure some level of
# consistency, defaults, and avoid errors from typos, etc.
#
###

doc_intro = """
## About the API

### Purpose

The purpose of the CoCalc API (application programming interface) is to make
essential operations within the CoCalc platform available to automated
clients. This allows embedding of CoCalc services within other products
and customizing the external look and feel of the application.

### Protocol and Data Format

Each API command is invoked using an HTTPS PUT request.
All commands support request parameters in JSON format, with request header
`Content-Type: application/json`. Many commands (those that do not
require lists or objects as parameters)
also accept request parameters as key-value pairs, i.e.
`Content-Type: application/x-www-form-urlencoded`.

Responses are formatted as JSON strings.
Note that it is possible for a request to fail and return
a response code of 200. In that case, the response
string may contain helpful information on the nature of
the failure. In other cases, if the request cannnot
be completed, a response code other than 200 may be
returned, and the response body may be a
generic HTML message rather than a JSON string.

### Authentication

A valid API key is required on all API requests.
To obtain a key, log into
CoCalc and click on Settings (gear icon next to user name at upper
right), and look under `Account Settings`.
With the `API key` dialogue, you can create a key,
view a previously assigned key, generate a replacement key,
and delete your key entirely.

Your API key carries access privileges, just like your
login and password.
__Keep it secret.__
Do not share your API key with others or post it in publicly accessible
forums.

### Additional References

- The CoCalc PostgreSQL schema definition
[src/smc-util/db-schema.coffee](https://github.com/sagemathinc/cocalc/blob/master/src/smc-util/db-schema.coffee)
has information on tables and fields used with the API `query` request.
- The API test suite
[src/smc-hub/test/api/](https://github.com/sagemathinc/cocalc/tree/master/src/smc-hub/test/api)
contains mocha unit tests for the API messages.
- The CoCalc message definition file
[src/smc-util/message.coffee](https://github.com/sagemathinc/cocalc/blob/master/src/smc-util/message.coffee)
contains the source for this guide.

### API Message Reference

The remainder of this guide explains the individual API endpoints.
Each API request definition begins with the path of the
URL used to invoke the request,
for example `/api/v1/change_email_address`.
The path name ends with the name of the request,
for example, `change_email_address`.
Following the path is the list of options.
After options are one or more sample invocations
illustrating format of the request as made with the `curl`
command, and the format of the response.

The following two options appear on all API messages
(request parameters are often referred to
as 'options' in the guide):

- **event**: the command to be executed, for example "ping"
- **id**: uuid for the API call, returned in response in most cases.
If id is not provided in the API message, a random id will be
generated and returned in the response.
"""

misc     = require('./misc')
defaults = misc.defaults
required = defaults.required
_        = require('underscore')


message = (obj) ->
    exports[obj.event] = (opts={}, strict=false) ->
        if opts.event?
            throw Error("ValueError: must not define 'event' when calling message creation function (opts=#{JSON.stringify(opts)}, obj=#{JSON.stringify(obj)})")
        defaults(opts, obj, false, strict)
    return obj

# message2 for "version 2" of the message definitions
# TODO document it, for now just search for "message2" to see examples
message2 = (obj) ->

    mk_desc = (val) ->
        desc = val.desc
        if val.init == required
            desc += ' (required)'
        else if val.init?
            desc += " (default: #{misc.to_json(val.init)})"
        return desc

    # reassembling a version 1 message from a version 2 message
    mesg_v1       = _.mapObject(obj.fields, ((val) -> val.init))
    mesg_v1.event = obj.event
    # extracting description for the documentation
    fdesc = _.mapObject(obj.fields, mk_desc)
    exports.documentation.events[obj.event] =
                                description   : obj.desc ? ''
                                fields        : fdesc
    # ... and the examples
    exports.examples[obj.event] = obj.examples
    # wrapped version 1 message
    message(mesg_v1)
    return obj

# messages that can be used by the HTTP api.   {'event':true, ...}
exports.api_messages = {}

# this holds the documentation for the message protocol
exports.documentation =
    intro  : doc_intro
    events : {}

# holds all the examples: list of expected in/out objects for each message
exports.examples = {}

API = (obj) ->
    # obj could be message version 1 or 2!
    exports.api_messages[obj.event] = true

############################################
# Compute server messages
#############################################

message
    event : 'compute_server_status'
    status : undefined

# Message for actions using a compute server
message
    event      : 'compute'
    project_id : undefined
    action     : required    # open, save, ...
    args       : undefined
    param      : undefined   # deprecate
    id         : undefined

message
    event      : 'project_state_update'
    project_id : required
    state      : required
    time       : required
    state_error : undefined  # error if there was one transitioning to this state


############################################
# Sage session management; executing code
#############################################

# hub --> sage_server&console_server, etc. and browser --> hub
message
    event        : 'start_session'
    type         : required           # "sage", "console";  later this could be "R", "octave", etc.
    # TODO: project_id should be required
    project_id   : undefined          # the project that this session will start in
    session_uuid : undefined          # set by the hub -- client setting this will be ignored.
    params       : undefined          # extra parameters that control the type of session
    id           : undefined
    limits       : undefined

# hub --> browser
message
    event         : 'session_started'
    id            : undefined
    session_uuid  : undefined
    limits        : undefined
    data_channel  : undefined # The data_channel is a single UTF-16
                              # character; this is used for
                              # efficiently sending and receiving
                              # non-JSON data (except channel
                              # '\u0000', which is JSON).

# hub --> client
message
    event         : 'session_reconnect'
    session_uuid  : undefined   # at least one of session_uuid or data_channel must be defined
    data_channel  : undefined


#

# client --> hub
message
    event        : 'connect_to_session'
    id           : undefined
    type         : required
    project_id   : required
    session_uuid : required
    params       : undefined          # extra parameters that control the type of session -- if we have to create a new one

message
    event         : 'session_connected'
    id            : undefined
    session_uuid  : required
    data_channel  : undefined  # used for certain types of sessions
    history       : undefined  # used for console/terminal sessions


# sage_server&console_server --> hub
message
    event  : 'session_description'
    pid    : required
    limits : undefined

# client <----> hub <--> sage_server
message
    event        : 'terminate_session'
    project_id   : undefined
    session_uuid : undefined
    reason       : undefined
    done         : undefined

message
    event        : 'execute_code'
    id           : undefined
    code         : required
    data         : undefined
    session_uuid : undefined
    cell_id      : undefined  # optional extra useful information about which cells is being executed
    preparse     : true
    allow_cache  : true

# Output resulting from evaluating code that is displayed by the browser.
# sage_server --> local hub --> hubs --> clients
message
    event        : 'output'
    id           : undefined   # the id for this particular computation
    stdout       : undefined   # plain text stream
    stderr       : undefined   # error text stream -- colored to indicate an error
    html         : undefined   # arbitrary html stream
    md           : undefined   # github flavored markdown
    tex          : undefined   # tex/latex stream -- is an object {tex:..., display:...}
    d3           : undefined   # d3 data document, e.g,. {d3:{viewer:'graph', data:{...}}}
    hide         : undefined   # 'input' or 'output'; hide display of given component of cell
    show         : undefined   # 'input' or 'output'; show display of given component of cell
    auto         : undefined   # true or false; sets whether or not cell auto-executess on process restart
    javascript   : undefined   # javascript code evaluation stream (see also 'execute_javascript' to run code directly in browser that is not part of the output stream).
    interact     : undefined   # create an interact layout defined by a JSON object
    obj          : undefined   # used for passing any JSON-able object along as output; this is used, e.g., by interact.
    file         : undefined   # used for passing a file -- is an object {filename:..., uuid:..., show:true}; the file is at https://cloud.sagemath.com/blobs/filename?uuid=[the uuid]
    raw_input    : undefined   # used for getting blocking input from client -- {raw_input:{prompt:'input stuff?', value:'', submitted:false}}
    done         : false       # the sequences of messages for a given code evaluation is done.
    session_uuid : undefined   # the uuid of the session that produced this output
    once         : undefined   # if given, message is transient; it is not saved by the worksheet, etc.
    clear        : undefined   # if true, clears all output of the current cell before rendering message.
    events       : undefined   # {'event_name':'name of Python callable to call', ...} -- only for images right now

# This message tells the client to execute the given Javascript code
# in the browser.  (For safety, the client may choose to ignore this
# message.)  If coffeescript==true, then the code is assumed to be
# coffeescript and is first compiled to Javascript.  This message is
# "out of band", i.e., not meant to be part of any particular output
# cell.  That is why there is no id key.

# sage_server --> hub --> client
message
    event        : 'execute_javascript'
    session_uuid : undefined              # set by the hub, since sage_server doesn't (need to) know the session_uuid.
    code         : required
    obj          : undefined
    coffeescript : false
    cell_id      : undefined    # if set, eval scope contains an object cell that refers to the cell in the worksheet with this id.


############################################
# Information about several projects or accounts
#############################################

API message2
    event       : 'get_usernames'
    fields:
        id:
             init  : undefined
             desc  : 'A unique UUID for the query'
        account_ids:
             init  : required
             desc  : 'list of account_ids'
    desc        : """
Get first and last names for a list of account ids.

Note: Options for the `get_usernames` API message must be sent as JSON object.

Example:
```
  curl -u sk_abcdefQWERTY090900000000: -H "Content-Type: application/json" \\
    -d '{"account_ids":["cc3cb7f1-14f6-4a18-a803-5034af8c0004","9b896055-920a-413c-9172-dfb4007a8e7f"]}' \\
    https://cocalc.com/api/v1/get_usernames
  ==>  {"event":"usernames",
        "id":"32b485a8-f214-4fda-a622-4dbfe0db2b9c",
        "usernames": {
           "cc3cb7f1-14f6-4a18-a803-5034af8c0004":{"first_name":"John","last_name":"Smith"},
           "9b896055-920a-413c-9172-dfb4007a8e7f":{"first_name":"Jane","last_name":"Doe"}}}
```
"""

message
    event       : 'usernames'
    id          : undefined
    usernames   : required


############################################
# Account Management
#############################################

# client --> hub
API message2
    event          : 'create_account'
    fields:
        id:
             init  : undefined
             desc  : 'A unique UUID for the query'

        first_name:
            init   : required
        last_name:
            init   : required
        email_address:
            init   : required
        password:
            init   : required
            desc   : 'must be between 6 and 64 characters in length'
        agreed_to_terms:
            init   : required
            desc   : 'must be true for request to succeed'
        token:
            init   : undefined   # only required when token is set.
            desc   : 'account creation token - see src/dev/docker/README.md'
    desc           : """
Examples:

Create a new account:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d first_name=John00 \\
    -d last_name=Doe00 \\
    -d email_address=jd@some_email \\
    -d password=xyzabc09090 \\
    -d agreed_to_terms=true https://cocalc.com/api/v1/create_account
```

Option `agreed_to_terms` must be present and specified as true.
Account creation fails if there is already an account using the
given email address, if `email_address` is improperly formatted,
and if password is fewer than 6 or more than 64 characters.

Attempting to create the same account a second time results in an error:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d first_name=John00 \\
    -d last_name=Doe00 \\
    -d email_address=jd@some_email \\
    -d password=xyzabc09090 \\
    -d agreed_to_terms=true https://cocalc.com/api/v1/create_account
  ==> {"event":"account_creation_failed",
       "id":"2332be03-aa7d-49a6-933a-cd9824b7331a",
       "reason":{"email_address":"This e-mail address is already taken."}}
```
"""

message
    event      : 'account_created'
    id         : undefined
    account_id : required

# hub --> client
message
    event          : 'account_creation_failed'
    id             : undefined
    reason         : required

# client --> hub
API message2
    event        : 'delete_account'
    fields:
        id:
           init  : undefined
           desc  : 'A unique UUID for the query'
        account_id:
           init  : required
           desc  : 'account_id for account to be deleted'
    desc         : """
Example:

Delete an existing account:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d account_id=99ebde5c-58f8-4e29-b6e4-b55b8fd71a1b \\
    https://cocalc.com/api/v1/delete_account
  ==> {"event":"account_deleted","id":"9e8b68ac-08e8-432a-a853-398042fae8c9"}
```

Event `account_deleted` is also returned if the account was already
deleted before the API call, or if the account never existed.

After successful `delete_account`, the owner of the deleted account
will not be able to login, but will still be listed as collaborator
or owner on projects which the user collaborated on or owned
respectively.
"""

# hub --> client
message
    event        : 'account_deleted'
    id           : undefined
    error        : undefined

# client --> hub
message
    id             : undefined
    event          : 'sign_in'
    email_address  : required
    password       : required
    remember_me    : false

message
    id         : undefined
    event      : 'sign_in_using_auth_token'
    auth_token : required

# hub --> client
message
    id     : undefined
    event  : 'remember_me_failed'
    reason : required

# client --> hub
message
    id             : undefined
    event          : 'sign_in_failed'
    email_address  : required
    reason         : required

# hub --> client; sent in response to either create_account or log_in
message
    event          : 'signed_in'
    id             : undefined     # message uuid
    remember_me    : required      # true if sign in accomplished via remember_me cookie; otherwise, false.
    hub            : required      # ip address (on vpn) of hub user connected to.
    account_id     : required      # uuid of user's account
    email_address  : undefined     # email address they signed in under
    first_name     : undefined
    last_name      : undefined

# client --> hub
message
    event          : 'sign_out'
    everywhere     : false
    id             : undefined

# hub --> client
message
    event          : 'signed_out'
    id             : undefined

# client --> hub
API message2
    event          : 'change_password'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        email_address:
            init  : required
            desc  : 'email address for account whose password is changed'
        old_password:
            init  : ""
            desc  : ''
        new_password:
            init  : required
            desc  : 'must be between 6 and 64 characters in length'
    desc           : """
Given email address and old password for an account, set a new password.

Example:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d email_address=... \\
    -d old_password=... \\
    -d new_password=... \\
    https://cocalc.com/api/v1/change_password
  ==> {"event":"changed_password","id":"41ff89c3-348e-4361-ad1d-372b55e1544a"}
```
"""

# hub --> client
# if error is true, that means the password was not changed; would
# happen if password is wrong (message:'invalid password').
message
    event          : 'changed_password'
    id             : undefined
    error          : undefined

# client --> hub: "please send a password reset email"
API message2
    event         : "forgot_password"
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        email_address:
            init  : required
            desc  : 'email address for account requesting password reset'
    desc          : """
Given the email address of an existing account, send password reset email.

Example:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d email_address=... \\
    https://cocalc.com/api/v1/forgot_password
  ==> {"event":"forgot_password_response",
       "id":"26ed294b-922b-47e1-8f3f-1e54d8c8e558",
       "error":false}
```
"""

# hub --> client  "a password reset email was sent, or there was an error"
message
    event         : "forgot_password_response"
    id            : undefined
    error         : false

# client --> hub: "reset a password using this id code that was sent in a password reset email"
API message2
    event         : "reset_forgot_password"
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        reset_code:
            init  : required
            desc  : 'id code that was sent in a password reset email'
        new_password:
            init  : required
            desc  : 'must be between 6 and 64 characters in length'
    desc          : """
Reset password, given reset code.

Example:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d reset_code=35a0eea6-370a-45c3-ab2f-3210df68748f \\
    -d new_password=qjqhddfsfj \\
    https://cocalc.com/api/v1/reset_forgot_password
  ==> {"event":"reset_forgot_password_response","id":"85bd6027-644d-4859-9e17-5e835bd47570","error":false}
```
"""

message
    event         : "reset_forgot_password_response"
    id            : undefined
    error         : false

# client --> hub
API message2
    event             : 'change_email_address'
    fields:
        id:
            init      : undefined
            desc      : 'A unique UUID for the query'
        account_id:
            init      : required
            desc      :  'account_id for account whose email address is changed'
        old_email_address:
            init      : ""
            desc      : 'ignored -- deprecated'
        new_email_address:
            init      : required
            desc      : ''
        password:
            init      :""
            desc      : ''
    desc:"""
Given the `account_id` for an account, set a new email address.

Examples:

Successful change of email address.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d account_id=99ebde5c-58f8-4e29-b6e4-b55b8fd71a1b \\
    -d password=secret_password \\
    -d new_email_address=new@email.com \\
    https://cocalc.com/api/v1/change_email_address
  ==> {"event":"changed_email_address",
       "id":"8f68f6c4-9851-4b88-bd65-37cb983298e3",
       "error":false}
```

Fails if new email address is already in use.

```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d account_id=99ebde5c-58f8-4e29-b6e4-b55b8fd71a1b \\
    -d password=secret_password \\
    -d new_email_address=used@email.com \\
    https://cocalc.com/api/v1/change_email_address
  ==> {"event":"changed_email_address",
       "id":"4501f022-a57c-4aaf-9cd8-af0eb05ebfce",
       "error":"email_already_taken"}
```

**Note:** `account_id` and `password` must match the `id` of the current login.
"""

# hub --> client
message
    event               : 'changed_email_address'
    id                  : undefined
    error               : false  # some other error
    ttl                 : undefined   # if user is trying to change password too often, this is time to wait



# Unlink a passport auth for this account.
# client --> hub
API message2
    event    : 'unlink_passport'
    fields:
        strategy:
            init  : required
            desc  : 'passport strategy'
        id:
            init  : required
            desc  : 'numeric id for user and passport strategy'
    desc:"""
Unlink a passport auth for the account.

Strategies are defined in the database and may be viewed at [/auth/strategies](https://cocalc.com/auth/strategies).

Example:

Get passport id for some strategy for current user.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H "Content-Type: application/json" \\
    -d '{"query":{"accounts":{"account_id":"e6993694-820d-4f78-bcc9-10a8e336a88d","passports":null}}}' \\
    https://cocalc.com/api/v1/query
  ==> {"query":{"accounts":{"account_id":"e6993694-820d-4f78-bcc9-10a8e336a88d",
                            "passports":{"facebook-14159265358":{"id":"14159265358",...}}}},
       "multi_response":false,
       "event":"query",
       "id":"a2554ec8-665b-495b-b0e2-8e248b54eb94"}
```

Unlink passport for that strategy and id.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d strategy=facebook \\
    -d id=14159265358 \\
    https://cocalc.com/api/v1/unlink_passport
  ==> {"event":"success",
       "id":"14159265358"}
```

Note that success is returned regardless of whether or not passport was linked
for the given strategy and id before issuing the API command.
"""
message
    event : 'error'
    id    : undefined
    error : undefined

message
    event : 'success'
    id    : undefined

# You need to reconnect.
message
    event : 'reconnect'
    id    : undefined
    reason : undefined  # optional to make logs more informative


######################################################################################
# This is a message that goes
#      hub --> client
# In response, the client grabs "/cookies?id=...,set=...,get=..." via an AJAX call.
# During that call the server can get/set HTTP-only cookies.
# (Note that the /cookies url gets customized by base_url.)
######################################################################################
message
    event       : 'cookies'
    id          : required
    url         : "/cookies"
    get         : undefined  # name of a cookie to get
    set         : undefined  # name of a cookie to set
    value       : undefined  # value to set cookie to

###

Project Server <---> Hub interaction

These messages are mainly focused on working with individual projects.

Architecture:

  * The database stores a files object (with the file tree), logs
    (of each branch) and a sequence of git bundles that when
    combined together give the complete history of the repository.
    Total disk usage per project is limited by hard/soft disk quota,
    and includes the space taken by the revision history (the .git
    directory).

  * A project should only be opened by at most one project_server at
    any given time (not implemented: if this is violated then we'll
    merge the resulting conflicting repo's.)

  * Which project_server that has a project opened is stored in the
    database.  If a hub cannot connect to a given project server,
    the hub assigns a new project_server for the project and opens
    the project on the new project_server.  (The error also gets
    logged to the database.)  All hubs will use this new project
    server henceforth.

###

# The open_project message causes the project_server to create a new
# project or prepare to receive one (as a sequence of blob messages)
# from a hub.
#
# hub --> project_server
message
    event        : 'open_project'
    id           : required
    project_id   : required  # uuid of the project, which impacts
                             # where project is extracted, etc.
    quota        : required  # Maximum amount of disk space/inodes this
                             # project can use.  This is an object
                             #    {disk:{soft:megabytes, hard:megabytes}, inode:{soft:num, hard:num}}
    idle_timeout : required  # A time in seconds; if the project_server
                             # does not receive any messages related
                             # to this project for this many seconds,
                             # then it does the same thing as when
                             # receiving a 'close_project' message.
    ssh_public_key: required # ssh key of the one UNIX user that is allowed to access this account (this is running the hub).

# A project_server sends the project_opened message to the hub once
# the project_server has received and unbundled all bundles that
# define a project.
# project_server --> hub
message
    event : 'project_opened'
    id    : required

######################################################################
# Execute a shell command in a given project
######################################################################

# client --> project
API message2
    event      : 'project_exec'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        project_id:
            init  : required
            desc  : 'id of project where command is to be executed'
        path:
            init  : ''
            desc  : 'path of working directory for the command'
        command:
            init  : required
            desc  : 'command to be executed'
        args:
            init  : []
            desc  : 'command line options for the command'
        timeout:
            init  : 10
            desc  : 'maximum allowed time, in seconds'
        max_output:
            init  : undefined
            desc  : 'maximum number of characters in the output'
        bash:
            init  : false
            desc  : 'if true, args are ignored and command is run as a bash command'
        err_on_exit:
            init  : true
            desc  : 'if exit code is nonzero send error return message instead of the usual output'
     desc: """
Execute a shell command in a given project.

Examples:

Simple built-in shell command.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d command=pwd \\
    -d project_id=e49e86aa-192f-410b-8269-4b89fd934fba \\
    https://cocalc.com/api/v1/project_exec
  ==> {"event":"project_exec_output",
       "id":"8a78a37d-b2fb-4e29-94ae-d66acdeac949",
       "stdout":"/projects/e49e86aa-192f-410b-8269-4b89fd934fba\\n","stderr":"","exit_code":0}
```

Shell command with different working directory.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d command=pwd \\
    -d path=Private \\
    -d project_id=e49e86aa-192f-410b-8269-4b89fd934fba \\
    https://cocalc.com/api/v1/project_exec
  ==> {"event":"project_exec_output",
       "id":"8a78a37d-b2fb-4e29-94ae-d66acdeac949",
       "stdout":"/projects/e49e86aa-192f-410b-8269-4b89fd934fba/Private\\n","stderr":"","exit_code":0}
```

Command line arguments specified by 'args' option. Note JSON format for request parameters.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H 'Content-Type: application/json' \\
    -d '{"command":"echo","args":["xyz","abc"],"project_id":"e49e86aa-192f-410b-8269-4b89fd934fba"}' \\
    https://cocalc.com/api/v1/project_exec
  ==> {"event":"project_exec_output",
       "id":"39289ba7-0333-48ad-984e-b25c8b8ffa0e",
       "stdout":"xyz abc\\n",
       "stderr":"",
       "exit_code":0}
```

Limiting output of the command to 3 characters.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H 'Content-Type: application/json' \\
    -d '{"command":"echo","args":["xyz","abc"],"max_output":3,"project_id":"e49e86aa-192f-410b-8269-4b89fd934fba"}' \\
    https://cocalc.com/api/v1/project_exec
  ==> {"event":"project_exec_output",
       "id":"02feab6c-a743-411a-afca-8a23b58988a9",
       "stdout":"xyz (truncated at 3 characters)",
       "stderr":"",
       "exit_code":0}
```

Setting a timeout for the command.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H 'Content-Type: application/json' \\
    -d '{"command":"sleep 5","timeout":2,"project_id":"e49e86aa-192f-410b-8269-4b89fd934fba"}' \\
    https://cocalc.com/api/v1/project_exec
  ==>  {"event":"error",
        "id":"86fea3f0-6a90-495b-a541-9c14a25fbe58",
        "error":"Error executing command 'sleep 5' with args '' -- killed command 'bash /tmp/f-11757-1677-8ei2z0.t4fex0qkt9', , "}
```

Notes:
- Argument `command` may invoke an executable file or a built-in shell command. It may include
  a path and command line arguments.
- If option `args` is provided, options must be sent as a JSON object.
- Argument `path` is optional. When provided, `path` is relative to home directory in target project
  and specifies the working directory in which the command will be run.
"""

# project --> client
message
    event      : 'project_exec_output'
    id         : required
    stdout     : required
    stderr     : required
    exit_code  : required


######################################################################
# Jupyter server
######################################################################

# starts jupyter hub server and reports the port it is running on
# hub <--> project
message
    event       : 'jupyter_port'
    port        : undefined  # gets set in response
    id          : undefined
    mathjax_url : undefined  # e.g. '/static/mathjax-2.6.1/MathJax.js'

#############################################################################


# The read_file_from_project message is sent by the hub to request
# that the project_server read a file from a project and send it back
# to the hub as a blob.  Also sent by client to hub to request a file
# or directory. If path is a directory, the optional archive field
# specifies how to create a single file archive, with supported
# options including:  'tar', 'tar.bz2', 'tar.gz', 'zip', '7z'.
#
# client --> hub --> project_server
message
    event        : 'read_file_from_project'
    id           : undefined
    project_id   : required
    path         : required
    archive      : 'tar.bz2'

# The file_read_from_project message is sent by the project_server
# when it finishes reading the file from disk.
# project_server --> hub
message
    event        : 'file_read_from_project'
    id           : required
    data_uuid    : required  # The project_server will send the raw data of the file as a blob with this uuid.
    archive      : undefined  # if defined, means that file (or directory) was archived (tarred up) and this string was added to end of filename.


# hub --> client
message
    event        : 'temporary_link_to_file_read_from_project'
    id           : required
    url          : required

# The client sends this message to the hub in order to write (or
# create) a plain text file (binary files not allowed, since sending
# them via JSON makes no sense).
# client --> hub
API message2
    event        : 'read_text_file_from_project'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        project_id:
            init  : required
            desc  : 'id of project containing file to be read'
        path:
            init  : required
            desc  : 'path to file to be read in target project'
    desc: """
Read a text file in the project whose id is supplied.
User must be owner or collaborator in the target project.
Argument 'path' is relative to home directory in target project.
Unix user in the target project must have permissions to read file
and containing directories if they do not already exist.

Example:

Read a text file.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d project_id=e49e86aa-192f-410b-8269-4b89fd934fba \\
    -d path=Assignments/A1/h1.txt \\
    https://cocalc.com/api/v1/read_text_file_from_project
  ==> {"event":"text_file_read_from_project",
       "id":"481d6055-5609-450f-a229-480e518b2f84",
       "content":"hello"}
```
"""

# hub --> client
message
    event        : 'text_file_read_from_project'
    id           : required
    content      : required

# The write_file_to_project message is sent from the hub to the
# project_server to tell the project_server to write a file to a
# project.  If the path includes directories that don't exists,
# they are automatically created (this is in fact the only way
# to make a new directory).
# hub --> project_server
message
    event        : 'write_file_to_project'
    id           : required
    project_id   : required
    path         : required
    data_uuid    : required  # hub sends raw data as a blob with this uuid immediately.

# The client sends this message to the hub in order to write (or
# create) a plain text file (binary files not allowed, since sending
# them via JSON makes no sense).
# client --> hub
API message2
    event        : 'write_text_file_to_project'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        project_id:
            init  : required
            desc  : 'id of project where file is created'
        path:
            init  : required
            desc  : 'path to file, relative to home directory in destination project'
        content:
            init  : required
            desc  : 'contents of the text file to be written'
    desc:"""
Create a text file in the target project.
User must be owner or collaborator in the target project.
Directories containing the file are created if they do not exist already.
Unix user in the target project must have permissions to create file
and containing directories if they do not already exist.
If a file already exists at the destination path, it is overwritten.

Example:

Create a text file.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d project_id=e49e86aa-192f-410b-8269-4b89fd934fba \\
    -d "content=hello$'\\n'world" \\
    -d path=Assignments/A1/h1.txt \\
    https://cocalc.com/api/v1/write_text_file_to_project
```
"""

# The file_written_to_project message is sent by a project_server to
# confirm successful write of the file to the project.
# project_server --> hub
message
    event        : 'file_written_to_project'
    id           : required

############################################
# Managing multiple projects
############################################

# client --> hub
API message2
    event      : 'create_project'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        title     :
            init  : ''
            desc  : 'project title'
        description:
            init  : ''
            desc  : 'project description'
        start     :
            init  : false
            desc  : 'start running the moment the project is created -- uses more resources, but possibly better user experience'
    desc       : """
Example:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d title='MY NEW PROJECT' \\
    -d description='sample project' \\
    https://cocalc.com/api/v1/create_project
  == > {"event":"project_created",
        "id":"0b4df293-d518-45d0-8a3c-4281e501b85e",
        "project_id":"07897899-6bbb-4fbc-80a7-3586c43348d1"}
```
"""

# hub --> client
message
    event      : 'project_created'
    id         : required
    project_id : required


# hub --> client(s)
message
    event      : 'project_list_updated'

## search ---------------------------

# client --> hub
API message2
    event : 'user_search'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        query:
            init  : required
            desc  : "comma separated list of email addresses or strings such as 'foo bar'"
        limit:
            init  : 20
            desc  : 'maximum number of results returned'
    desc: """
There are two possible item types in the query list: email addresses
and strings that are not email addresses. An email query item will return
account id, first name, last name, and email address for the unique
account with that email address, if there is one. A string query item
will return account id, first name, and last name for all matching
accounts.

We do not reveal email addresses of users queried by name.

String query matches first and last names that start with the given string.
If a string query item consists of two strings separated by space,
the search will return accounts in which the first name begins with one
of the two strings and the last name begins with the other.
String and email queries may be mixed in the list for a single
user_search call. Searches are case-insensitive.

Note: there is a hard limit of 50 returned items in the results.

Examples:

Search for account by email.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d query=jd@m.local \\
    https://cocalc.com/api/v1/user_search
  ==> {"event":"user_search_results",
       "id":"3818fa50-b892-4167-b9d9-d22d521b36af",
       "results":[{"account_id":"96c523b8-321e-41a3-9523-39fde95dc71d",
                   "first_name":"John",
                   "last_name":"Doe",
                   "email_address":"jd@m.local"}
```

Search for at most 3 accounts where first and last name begin with 'foo' or 'bar'.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d 'query=foo bar'\\
    -d limit=3 \\
    https://cocalc.com/api/v1/user_search
  ==> {"event":"user_search_results",
       "id":"fd9b025b-25d0-4e27-97f4-2c080bb07155",
       "results":[{"account_id":"1a842a67-eed3-405d-a222-2f23a33f675e",
                   "first_name":"foo",
                   "last_name":"bar"},
                  {"account_id":"0e9418a7-af6a-4004-970a-32fafe733f29",
                   "first_name":"bar123",
                   "last_name":"fooxyz"},
                  {"account_id":"93f8131c-6c21-401a-897d-d4abd9c6c225",
                   "first_name":"Foo",
                   "last_name":"Bar"}]}
```

The same result as the last example above would be returned with a
search string of 'bar foo'.
A name of "Xfoo YBar" would not match.

Note that email addresses are not returned for string search items.

Email and string search types may be mixed in a single query:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d 'query=foo bar,jd@m.local' \\
    -d limit=4 \\
    https://cocalc.com/api/v1/user_search
```
"""

# hub --> client
message
    event   : 'user_search_results'
    id      : undefined
    results : required  # list of {first_name:, last_name:, account_id:} objects.

# hub --> client
message
    event : 'project_users'
    id    : undefined
    users : required   # list of {account_id:?, first_name:?, last_name:?, mode:?, state:?}

API message2
    event      : 'invite_collaborator'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        project_id:
            init  : required
            desc  : 'project_id of project into which user is invited'
        account_id:
            init  : required
            desc  : 'account_id of invited user'
    desc       : """
Invite a user who already has a CoCalc account to
become a collaborator on a project. You must be owner
or collaborator on the target project.

Example:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d account_id=99ebde5c-58f8-4e29-b6e4-b55b8fd71a1b \\
    -d project_id=18955da4-4bfa-4afa-910c-7f2358c05eb8 \\
    https://cocalc.com/api/v1/invite_collaborator
  ==> {"event":"success",
       "id":"e80fd64d-fd7e-4cbc-981c-c0e8c843deec"}
```
"""

API message2
    event      : 'remove_collaborator'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        project_id:
            init  : required
            desc  : 'project_id of project from which user is removed'
        account_id:
            init  : required
            desc  : 'account_id of removed user'
    desc       : """
Remove a user from a CoCalc project.
You must be owner or collaborator on the target project.
You cannot remove the project owner.

Example:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d account_id=99ebde5c-58f8-4e29-b6e4-b55b8fd71a1b \\
    -d project_id=18955da4-4bfa-4afa-910c-7f2358c05eb8 \\
    https://cocalc.com/api/v1/remove_collaborator
  ==> {"event":"success",
       "id":"e80fd64d-fd7e-4cbc-981c-c0e8c843deec"}
```
"""

# DANGER -- can be used to spam people.
API message2
    event         : 'invite_noncloud_collaborators'
    fields        :
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        project_id:
            init  : required
            desc  : 'project_id of project into which users are invited'
        to:
            init  : required
            desc  : 'comma- or semicolon-delimited string of email addresses'
        email:
            init  : required
            desc  : 'body of the email to be sent, may include HTML markup'
        title:
            init  : required
            desc  : 'string that will be used for project title in the email'
        link2proj:
            init  : required
            desc  : 'URL for the target project'
        replyto:
            init  : undefined
            desc  : 'Reply-To email address'
        replyto_name:
            init  : undefined
            desc  : 'Reply-To name'
        subject:
            init  : undefined
            desc  : 'email Subject'
    desc          : """
Invite users who do not already have a CoCalc account
to join a project.
An invitation email is sent to each user in the `to`
option.
Invitation is not sent if there is already a CoCalc
account with the given email address.
You must be owner or collaborator on the target project.

Limitations:
- Total length of the request message must be less than or equal to 1024 characters.
- Length of each email address must be less than 128 characters.


Example:
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d project_id=18955da4-4bfa-4afa-910c-7f2358c05eb8 \\
    -d to=someone@m.local \\
    -d 'email=Please sign up and join this project.' \\
    -d 'title=Class Project' \\
    -d link2proj=https://cocalc.com/projects/18955da4-4bfa-4afa-910c-7f2358c05eb8 \\
    https://cocalc.com/api/v1/invite_noncloud_collaborators
  ==>  {"event":"invite_noncloud_collaborators_resp",
        "id":"39d7203d-89b1-4145-8a7a-59e41d5682a3",
        "mesg":"Invited someone@m.local to collaborate on a project."}
```

Email sent by the previous example:

```
To: someone@m.local
From: CoCalc <invites@sagemath.com
Reply-To: help@sagemath.com
Subject: CoCalc Invitation

Please sign up and join this project.<br/><br/>\\n<b>
To accept the invitation, please sign up at\\n
<a href='https://cocalc.com'>https://cocalc.com</a>\\n
using exactly the email address 'someone@m.local'.\\n
Then go to <a href='https://cocalc.com/projects/18955da4-4bfa-4afa-910c-7f2358c05eb8'>
the project 'Team Project'</a>.</b><br/>
```
"""

message
    event      : 'invite_noncloud_collaborators_resp'
    id         : undefined
    mesg       : required

###
Send/receive the current webapp code version number.

This can be used by clients to suggest a refresh/restart.
The client may sends their version number on connect.
If the client sends their version and later it is out of date
due to an update, the server sends a new version number update
message to that client.
###
# client <---> hub
message
    event       : 'version'
    version     : undefined    # gets filled in by the hub
    min_version : undefined    # if given, then client version must be at least min_version to be allowed to connect.

#############################################
#
# Message sent in response to attempt to save a blob
# to the database.
#
# hub --> local_hub --> sage_server
#
#############################################
message
    event     : 'save_blob'
    id        : undefined
    sha1      : required     # the sha-1 hash of the blob that we just processed
    ttl       : undefined    # ttl in seconds of the blob if saved; 0=infinite
    error     : undefined    # if not saving, a message explaining why.


# remove the ttls from blobs in the blobstore.
# client --> hub
message
    event     : 'remove_blob_ttls'
    id        : undefined
    uuids     : required     # list of sha1 hashes of blobs stored in the blobstore

# DEPRECATED -- used by bup_server
message
    event      : 'storage'
    action     : required    # open, save, snapshot, latest_snapshot, close
    project_id : undefined
    param      : undefined
    id         : undefined

message
    event      : 'projects_running_on_server'
    id         : undefined
    projects   : undefined   # for response


###
Direct messaging between browser client and local_hub,
forwarded on by global hub after ensuring write access.
###
message
    event          : 'local_hub'
    project_id     : required
    timeout        : undefined
    id             : undefined
    multi_response : false
    message        : required   # arbitrary message


###########################################################
#
# Copy a path from one project to another.
#
###########################################################
API message2
    event : 'copy_path_between_projects'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        src_project_id:
            init  : required
            desc  : 'id of source project'
        src_path:
            init  : required
            desc  : 'relative path of directory or file in the source project'
        target_project_id:
            init  : required
            desc  : 'id of target project'
        target_path:
            init  : undefined
            desc  : 'defaults to src_path'
        overwrite_newer:
            init  : false
            desc  : 'overwrite newer versions of file at destination (destructive)'
        delete_missing:
            init  : false
            desc  : 'delete files in dest that are missing from source (destructive)'
        backup:
            init  : false
            desc  : 'make ~ backup files instead of overwriting changed files'
        timeout:
            init  : undefined
            desc  : 'seconds to wait before reporting "error" (though copy could still succeed)'
        exclude_history:
            init  : false
            desc  : 'if true, exclude all files of the form *.sage-history'
    desc  : """
Copy a file or directory from one project to another. User must be
owner or collaborator on both projects.

Note: the `timeout` option is passed to a call to the `rsync` command.
If no data is transferred for the specified number of seconds, then
the copy terminates. The default is 0, which means no timeout.

Relative paths (paths not beginning with '/') are relative to the user's
home directory in source and target projects.

Example:

Copy file `A/doc.txt` from source project to target project.
Folder `A` will be created in target project if it does not exist already.

```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d src_project_id=e49e86aa-192f-410b-8269-4b89fd934fba \\
    -d src_path=A/doc.txt \\
    -d target_project_id=2aae4347-214d-4fd1-809c-b327150442d8 \\
    https://cocalc.com/api/v1/copy_path_between_projects
  ==> {"event":"success",
       "id":"45d851ac-5ea0-4aea-9997-99a06c054a60"}
```
"""


#############################################
# Admin Functionality
#############################################

# client --> hub;  will result in an error if the user is not in the admin group.
message
    event       : 'project_set_quotas'
    id          : undefined
    project_id  : required     # the id of the project's id to set.
    memory      : undefined    # RAM in megabytes
    cpu_shares  : undefined    # fair sharing with everybody is 256, not 1 !!!
    cores       : undefined    # integer max number of cores user can use (>=1)
    disk_quota  : undefined    # disk quota in megabytes
    mintime     : undefined    # time in **seconds** until idle projects are terminated
    network     : undefined    # 1 or 0; if 1, full access to outside network
    member_host : undefined    # 1 or 0; if 1, project will be run on a members-only machine

###
Printing Files
###
message
    event        : "print_to_pdf"
    id           : undefined
    path         : required
    options      : undefined

message
    event        : 'printed_to_pdf'
    id           : undefined
    path         : required


###
Ping/pong -- used for clock sync, etc.
###
API message2
    event : 'ping'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
    desc  : """
Test API connection, return time as ISO string when server responds to ping.

Examples:

Omitting request id:
```
  curl -X POST -u sk_abcdefQWERTY090900000000: https://cocalc.com/api/v1/ping
  ==> {"event":"pong","id":"c74afb40-d89b-430f-836a-1d889484c794","now":"2017-05-24T13:29:11.742Z"}
```

Using `uuid` shell command to create a request id:
```
  uuid
  ==> 553f2815-1508-416d-8e69-2dde5af3aed8
  curl -u sk_abcdefQWERTY090900000000: https://cocalc.com/api/v1/ping -d id=553f2815-1508-416d-8e69-2dde5af3aed8
  ==> {"event":"pong","id":"553f2815-1508-416d-8e69-2dde5af3aed8","now":"2017-05-24T13:47:21.312Z"}
```

Using JSON format to provide request id:
```
  curl -u sk_abcdefQWERTY090900000000: -H "Content-Type: application/json" \\
    -d '{"id":"8ec4ac73-2595-42d2-ad47-0b9641043b46"}' https://cocalc.com/api/v1/ping
  ==> {"event":"pong","id":"8ec4ac73-2595-42d2-ad47-0b9641043b46","now":"2017-05-24T17:15:59.288Z"}
```
"""

message
    event : 'pong'
    id    : undefined
    now   : undefined  # timestamp



###
Reading listings and files from projects
without invoking the project server and
write auth requirement.  Instead the given
path in the project must be public.  These
functions don't even assume the client has
logged in.
###

# public request of listing of files in a project.
API message2
    event         : 'public_get_directory_listing'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        project_id:
            init  : required
            desc  : 'id of project containing public file to be read'
        path:
            init  : required
            desc  : 'path of directory in target project'
        hidden:
            init  : false
            desc  : 'show hidden files'
        time:
            init  : false
            desc  : 'sort by timestamp, with newest first'
        start:
            init  : 0
            desc  : ''
        limit:
            init  : -1
            desc  : ''
    desc:"""
Given a project id and relative path (i.e. not beginning with a slash),
list all public files and subdirectories under that path.
Path is required, but may be the empty string, in which case
a public listing of the home directory in the target project is
returned.

Examples:

Get public directory listing. Directory "Public" is shared and
contains one file "hello.txt" and one subdirectory "p2".

```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d path=Public \\
    -d project_id=9a19cca3-c53d-4c7c-8c0f-e166aada7bb6 \\
    https://cocalc.com/api/v1/public_get_directory_listing
  ==> {"event":"public_directory_listing",
       "id":"3e576b3b-b673-4d5c-9bce-780883f92958",
       "result":{"files":[{"size":41,"name":"hello.txt","mtime":1496430932},
                          {"isdir":true,"name":"p2","mtime":1496461616}]}
```
"""

message
    event         : 'public_directory_listing'
    id            : undefined
    result        : required

# public request of contents of a text file in project
API message2
    event         : 'public_get_text_file'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        project_id:
            init  : required
            desc  : 'id of project containing public file to be read'
        path:
            init  : required
            desc  : 'path to file to be read in target project'
    desc: """
Read a public (shared) text file in the project whose id is supplied.
User does not need to be owner or collaborator in the target project
and does not need to be logged into CoCalc.
Argument `path` is relative to home directory in target project.

Examples

Read a public file.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d project_id=e49e86aa-192f-410b-8269-4b89fd934fba \\
    -d path=Public/hello.txt
    https://cocalc.com/api/v1/public_get_text_file
  ==> {"event":"public_text_file_contents",
       "id":"2d0e2faa-893a-44c1-9f64-59203bbbb017",
       "data":"hello world\\nToday is Friday\\n"}
```

Attempt to read a file which is not public.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d project_id=e49e86aa-192f-410b-8269-4b89fd934fba \\
    -d path=Private/hello.txt
    https://cocalc.com/api/v1/public_get_text_file
  ==> {"event":"error","id":"0288b7d0-dda9-4895-87ba-aa71929b2bfb",
       "error":"path 'Private/hello.txt' of project with id 'e49e86aa-192f-410b-8269-4b89fd934fba' is not public"}+
```
"""

message
    event         : 'public_text_file_contents'
    id            : undefined
    data          : required

API message2
    event             : 'copy_public_path_between_projects'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        src_project_id:
            init  : required
            desc  : 'id of source project'
        src_path:
            init  : required
            desc  : 'relative path of directory or file in the source project'
        target_project_id:
            init  : required
            desc  : 'id of target project'
        target_path:
            init  : undefined
            desc  : 'defaults to src_path'
        overwrite_newer:
            init  : false
            desc  : 'overwrite newer versions of file at destination (destructive)'
        delete_missing:
            init  : false
            desc  : 'delete files in dest that are missing from source (destructive)'
        backup:
            init  : false
            desc  : 'make ~ backup files instead of overwriting changed files'
        timeout:
            init  : undefined
            desc  : 'how long to wait for the copy to complete before reporting error (though it could still succeed)'
        exclude_history:
            init  : false
            desc  : 'if true, exclude all files of the form *.sage-history'
    desc  : """
Copy a file or directory from public project to a project for which the
user is owner or collaborator.

Note: the `timeout` option is passed to a call to the `rsync` command.
If no data is transferred for the specified number of seconds, then
the copy terminates. The default is 0, which means no timeout.

Example:

Copy public file `PUBLIC/doc.txt` from source project to private file
`A/sample.txt` in target project.

```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d src_project_id=e49e86aa-192f-410b-8269-4b89fd934fba \\
    -d src_path=PUBLIC/doc.txt \\
    -d target_project_id=2aae4347-214d-4fd1-809c-b327150442d8 \\
    -d target_path=A/sample.txt \\
    https://cocalc.com/api/v1/copy_public_path_between_projects
  ==> {"event":"success",
       "id":"45d851ac-5ea0-4aea-9997-99a06c054a60"}
```
"""

API message2
    event : 'log_client_error'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        error:
            init  : required
            desc  : 'error string'
    desc  : """
Log an error so that CoCalc support can look at it.

In the following example, an explicit message id
is provided for future reference.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d id=34a424dc-1731-4b31-ba3d-fc8a484980d9 \\
    -d "error=cannot load library xyz" \\
    https://cocalc.com/api/v1/log_client_error
  ==> {"event":"success",
       "id":"34a424dc-1731-4b31-ba3d-fc8a484980d9"}
```

Note: the above API call will create the following record in the
`client_error_log` database table. This table is not readable
via the API and is intended for use by CoCalc support only:
```
[{"id":"34a424dc-1731-4b31-ba3d-fc8a484980d9",
  "event":"error",
  "error":"cannot load library xyz",
  "account_id":"1c87a139-9e13-4cdd-b02c-e7d41dcfe921",
  "time":"2017-07-06T02:32:41.176Z"}]
```
"""

message
    event        : 'webapp_error'
    name         : required  # string
    message      : required  # string
    comment      : undefined # string
    stacktrace   : undefined # string
    file         : undefined # string
    path         : undefined # string
    lineNumber   : undefined # int
    columnNumber : undefined # int
    severity     : undefined # string
    browser      : undefined # string, how feature.coffee detected the browser
    mobile       : undefined # boolean, feature.coffee::IS_MOBILE
    responsive   : undefined # boolean, feature.coffee::is_responsive_mode
    user_agent   : undefined # string
    smc_version  : undefined # string
    build_date   : undefined # string
    smc_git_rev  : undefined # string
    uptime       : undefined # string
    start_time   : undefined # timestamp


###
Stripe integration
###

# Set the stripe payment method for this user.

# customer info
API message
    event   : 'stripe_get_customer'
    id      : undefined

API message
    event    : 'stripe_customer'
    id       : undefined
    customer : undefined                 # if user already has a stripe customer account, info about it.
    stripe_publishable_key : undefined   # if stripe is configured for this SMC instance, this is the public API key.


# card
API message
    event   : 'stripe_create_source'
    id      : undefined
    token   : required

API message
    event   : 'stripe_delete_source'
    card_id : required
    id      : undefined

API message
    event   : 'stripe_set_default_source'
    card_id : required
    id      : undefined

API message
    event   : 'stripe_update_source'
    card_id : required
    info    : required                  # see https://stripe.com/docs/api/node#update_card, except we don't allow changing metadata
    id      : undefined


# subscriptions to plans

# Get a list of all currently available plans:
API message
    event    : 'stripe_get_plans'
    id       : undefined

API message
    event    : 'stripe_plans'
    id       : undefined
    plans    : required    # [{name:'Basic', projects:1, description:'...', price:'$10/month', trial_period:'30 days', ...}, ...]

# Create a subscription to a plan
API message
    event    : 'stripe_create_subscription'
    id       : undefined
    plan     : required   # name of plan
    quantity : 1
    coupon   : undefined

# Delete a subscription to a plan
API message
    event           : 'stripe_cancel_subscription'
    id              : undefined
    subscription_id : required
    at_period_end   : true

# Modify a subscription to a plan, e.g., change which projects plan applies to.
API message
    event           : 'stripe_update_subscription'
    id              : undefined
    subscription_id : required
    quantity        : undefined   # only give if changing
    projects        : undefined   # change associated projects from what they were to new list
    plan            : undefined   # change plan to this
    coupon          : undefined   # apply a coupon to this subscription

API message
    event          : 'stripe_get_subscriptions'
    id             : undefined
    limit          : undefined    # between 1 and 100 (default: 10)
    ending_before  : undefined    # see https://stripe.com/docs/api/node#list_charges
    starting_after : undefined

message
    event         : 'stripe_subscriptions'
    id            : undefined
    subscriptions : undefined

# charges
API message
    event          : 'stripe_get_charges'
    id             : undefined
    limit          : undefined    # between 1 and 100 (default: 10)
    ending_before  : undefined    # see https://stripe.com/docs/api/node#list_charges
    starting_after : undefined

message
    event   : 'stripe_charges'
    id      : undefined
    charges : undefined

# invoices
API message
    event          : 'stripe_get_invoices'
    id             : undefined
    limit          : undefined    # between 1 and 100 (default: 10)
    ending_before  : undefined    # see https://stripe.com/docs/api/node#list_customer_invoices
    starting_after : undefined

message
    event   : 'stripe_invoices'
    id      : undefined
    invoices : undefined

message
    event       : 'stripe_admin_create_invoice_item'
    id          : undefined
    email_address : undefined # one of email or account_id must be given.
    account_id  : undefined   # user who will be invoiced
    amount      : undefined   # currently in US dollars  (if amount or desc not given, then only creates customer, not invoice)
    description : undefined


###
Support Tickets → right now going through Zendesk
###

# client → hub
API message2
    event        : 'create_support_ticket'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
        username:
            init  : undefined
            desc  : 'name on the ticket'
        email_address:
            init  : required
            desc  : 'if there is no email_address in the account, there cannot be a ticket!'
        subject:
            init  : required
            desc  : 'like an email subject'
        body:
            init  : required
            desc  : 'html or md formatted text'
        tags:
            init  : undefined
            desc  : "a list of tags, like ['member']"
        account_id:
            init  : undefined
            desc  : 'account_id for the ticket'
        location:
            init  : undefined
            desc  : 'from the URL, to know what the requester is talking about'
        info:
            init  : undefined
            desc  : 'additional data dict, like browser/OS'
    desc  : """
Open a CoCalc support ticket.

Notes:

- If `account_id` is not provided, the ticket will be created, but ticket
info will not be returned by `get_support_tickets`.

- If `username` is not provided, `email_address` is used for the name on the ticket.

- `location` is used to provide a path to a specific project or file,
for example
```
/project/a17037cb-a083-4519-b3c1-38512af603a6/files/notebook.ipynb`
```

If present, the `location` string will be expanded to a complete URL and
appended to the body of the ticket.

- The `info` dict can be used to provide additional metadata, for example
```
{"user_agent":"Mozilla/5.0 ... Chrome/58.0.3029.96 Safari/537.36"}
```
- If the ticket concerns a CoCalc course, the project id of the course can
be included in the `info` dict, for example,
```
{"course":"0c7ae00c-ea43-4981-b454-90d4a8b1ac47"}
```
In that case, the course
project_id will be expanded to a URL and appended to the body of the
ticket.
- If `tags` or `info` are provided, options must be sent as a JSON object.

Example:

```
  curl -u sk_abcdefQWERTY090900000000: -H "Content-Type: application/json" \\
    -d '{"email_address":"jd@some_email", \\
         "subject":"package xyz", \\
         "account_id":"291f43c1-deae-431c-b763-712307fa6859", \\
         "body":"please install package xyz for use with Python3", \\
         "tags":["member"], \\
         "location":"/projects/0010abe1-9283-4b42-b403-fa4fc1e3be57/worksheet.sagews", \\
         "info":{"user_agent":"Mozilla/5.0","course":"cc8f1243-d573-4562-9aab-c15a3872d683"}}' \\
    https://cocalc.com/api/v1/create_support_ticket
  ==> {"event":"support_ticket_url",
       "id":"abd649bf-ea2d-4952-b925-e44c6903945e",
       "url":"https://sagemathcloud.zendesk.com/requests/0123"}
```
"""

message # client ← hub
    event        : 'support_ticket_url'
    id           : undefined
    url          : required

# client → hub
API message2
    event        : 'get_support_tickets'
    fields:
        id:
            init  : undefined
            desc  : 'A unique UUID for the query'
    desc  : """
Fetch information on support tickets for the user making the request.
See the example for details on what is returned.

Notes:

- There may be a delay of several minutes between the time a support ticket
is created with a given `account_id` and the time that ticket is
available to the account owner via `get_support_tickets`.
- Field `account_id` is not required because it is implicit from the request.
- Archived tickets are not returned.

Example:

```
curl -u sk_abcdefQWERTY090900000000:  -X POST \\
    https://cocalc.com/api/v1/get_support_tickets
  ==> {"event":"support_tickets",
       "id":"58bfd6f4-fd63-4602-82b8-676d92f8b0b8",
       "tickets":[{"id":1234,
                   "subject":"package xyz",
                   "description":"package xyz\\n\\nhttps://cocalc.com/projects/0010abe1-9283-4b42-b403-fa4fc1e3be57/worksheet.sagews\\n\\nCourse: https://cocalc.com/projects/cc8f1243-d573-4562-9aab-c15a3872d683",
                   "created_at":"2017-07-05T14:28:38Z",
                   "updated_at":"2017-07-05T14:29:29Z",
                   "status":"open",
                   "url":"https://sagemathcloud.zendesk.com/requests/0123"}]}
```
"""

message # client ← hub
    event        : 'support_tickets'
    id           : undefined
    tickets      : required  # json-list

###
Queries directly to the database (sort of like Facebook's GraphQL)
###

API message2
    event          : 'query'
    fields:
        id:
             init  : undefined
             desc  : 'A unique UUID for the query'
        query:
             init  : required
             desc  : 'The actual query'
        changes:
             init  : undefined
             desc  : ''
        multi_response:
             init  : false
             desc  : ''
        options:
             init  : undefined
             desc  : ''
    desc           : """
This queries directly the database (sort of Facebook's GraphQL)
Options for the 'query' API message must be sent as JSON object.
A query is either _get_ (read from database), or _set_ (write to database).
A query is _get_ if any query keys are null, otherwise the query is _set_.

Examples of _get_ query:

Get title and description for a project, given the project id.
```
  curl -u sk_abcdefQWERTY090900000000: -H "Content-Type: application/json" \\
    -d '{"query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d","title":null,"description":null}}}' \\
    https://cocalc.com/api/v1/query
  ==> {"event":"query",
       "id":"8ec4ac73-2595-42d2-ad47-0b9641043b46",
       "query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d",
                            "title":"MY NEW PROJECT 2",
                            "description":"desc 2"}},
       "multi_response":false}
```

Get project id, given title and description.
```
  curl -u sk_abcdefQWERTY090900000000: -H "Content-Type: application/json" \\
    -d '{"query":{"projects":{"project_id":null,"title":"MY NEW PROJECT 2","description":"desc 2"}}}' \\
    https://cocalc.com/api/v1/query
  ==> {"event":"query",
       "query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d",
                            "title":"MY NEW PROJECT 2",
                            "description":"desc 2"}},
       "multi_response":false,
       "id":"2be22e08-f00c-4128-b112-fa8581c2d584"}
```

Get users, given the project id.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H "Content-Type: application/json" \\
    -d '{"query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d","users":null}}}' \\
    https://cocalc.com/api/v1/query
  ==> {"event":"query",
       "query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d",
                            "users":{"6c28c5f4-3235-46be-b025-166b4dcaac7e":{"group":"owner"},
                                     "111634c0-7048-41e7-b2d0-f87129fd409e":{"group":"collaborator"}}}},
       "multi_response":false,
       "id":"9dd3ef3f-002b-4893-b31f-ff51440c855f"}
```


Show project upgrades. Like the preceding example, this is a query to get users.
In this example, there are no collaborators, but upgrades have been applied to the
selected project. Upgrades do not show if none are applied.

The project shows the following upgrades:
- cpu cores:       1
- memory:          3000 MB
- idle timeout:    24 hours (86400 seconds)
- internet access: true
- cpu shares:      3 (stored in database as 768 = 3 * 256)
- disk space:      27000 MB
- member hosting:  true

```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H "Content-Type: application/json" \\
    -d '{"query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d","users":null}}}' \\
    https://cocalc.com/api/v1/query
  ==> {"event":"query",
       "query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d",
                            "users":{"6c28c5f4-3235-46be-b025-166b4dcaac7e":{
                                         "group":"owner",
                                         "upgrades":{"cores":1,
                                                     "memory":3000,
                                                     "mintime":86400,
                                                     "network":1,
                                                     "cpu_shares":768,
                                                     "disk_quota":27000,
                                                     "member_host":1}}}}},
       "multi_response":false,
       "id":"9dd3ef3f-002b-4893-b31f-ff51440c855f"}
```

Examples of _set_ query.

Set title and description for a project, given the project id.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H "Content-Type: application/json" \\
    -d '{"query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d", \\
                              "title":"REVISED TITLE", \\
                              "description":"REVISED DESC"}}}' \\
    https://cocalc.com/api/v1/query
    ==> {"event":"query",
         "query":{},
         "multi_response":false,
         "id":"ad7d6b17-f5a9-4c5c-abc3-3823b1e1773f"}
```

Make a path public (publish a file).
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H "Content-Type: application/json" \\
    -d '{"query":{"public_paths":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d", \\
                                  "path":"myfile.txt", \\
                                  "description":"a shared text file"}}}' \\
    https://cocalc.com/api/v1/query
    ==> {"event":"query",
         "query":{},
         "multi_response":false,
         "id":"ad7d6b17-f5a9-4c5c-abc3-3823b1e1773f"}

```

Add an upgrade to a project. In the "get" example above showing project upgrades,
change cpu upgrades from 3 to 4. The `users` object is returned as
read, with `cpu_shares` increased to 1024 = 4 * 256.

```
  curl -u sk_abcdefQWERTY090900000000: \\
    -H "Content-Type: application/json" \\
    -d '{"query":{"projects":{"project_id":"29163de6-b5b0-496f-b75d-24be9aa2aa1d", \\
                              "users":{"6c28c5f4-3235-46be-b025-166b4dcaac7e":{ \\
                                           "group":"owner", \\
                                           "upgrades": {"cores":1, \\
                                                       "memory":3000, \\
                                                       "mintime":86400, \\
                                                       "network":1, \\
                                                       "cpu_shares":1024, \\
                                                       "disk_quota":27000, \\
                                                       "member_host":1}}}}}}' \\
    https://cocalc.com/api/v1/query
    ==> {"event":"query",
         "query":{},
         "multi_response":false,
         "id":"ec822d6f-f9fe-443d-9845-9cd5f68bac20"}
```


__NOTE:__ Information on which fields are gettable and settable in the database tables
via API message is in file 'db-schema.coffee', in CoCalc sources on GitHub at
https://github.com/sagemathinc/cocalc/blob/master/src/smc-util/db-schema.coffee

Within file 'db-schema.coffee':

- for _project_ fields you can get, see the definition of
`schema.projects.user_query.get.fields`
- for _project_ fields you can set, see the definition of
`schema.projects.user_query.set.fields`
- for _user account_ fields you can get, see the definition of
`schema.accounts.user_query.get.fields`
- for _user account_ fields you can set, see the definition of
`schema.accounts.user_query.set.fields`
"""
    examples: [  # TODO: create real examples!  These are not done.
        [{id: "uuid", query: 'example1-query'},
         {id: "uuid", event: 'query', response: "..."}
        ],
        [{id: "uuid", query: 'example2-query'},
         {id: "uuid", event: 'query', response: "..."}
        ]
    ]

message
    event : 'query_cancel'
    id    : undefined

# used to a get array of currently active change feed id's
message
    event          : 'query_get_changefeed_ids'
    id             : undefined
    changefeed_ids : undefined

###
API Key management for an account
###

# client --> hub
message
    event    : 'api_key'
    id       : undefined
    action   : required  # 'get', 'delete', 'regenerate'
    password : required

# hub --> client
message
    event : 'api_key_info'
    id    : undefined
    api_key : required

# client --> hub
API message2
    event        : 'user_auth'
    fields:
        id:
           init  : undefined
           desc  : 'A unique UUID for the query'
        account_id:
           init  : required
           desc  : 'account_id for account to get an auth token for'
        password:
           init  : required
           desc  : 'password for account to get token for'
    desc         : """
Example:

Obtain a temporary authentication token for an account, which
is a 24 character string. Tokens last for **12 hours**.  You can
only obtain an auth token for accounts that have a password.

```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d account_id=99ebde5c-58f8-4e29-b6e4-b55b8fd71a1b \\
    -d password=secret_password \\
    https://cocalc.com/api/v1/user_auth
  ==> {"event":"user_auth_token","id":"9e8b68ac-08e8-432a-a853-398042fae8c9","auth_token":"BQokikJOvBiI2HlWgH4olfQ2"}
```

You can now use the auth token to craft a URL like this:

    https://cocalc.com/app?auth_token=BQokikJOvBiI2HlWgH4olfQ2

and provide that to a user.  When they visit that URL, they will be temporarily signed in as that user.
"""

# hub --> client
message
    event      : 'user_auth_token'
    id         : undefined
    auth_token : required   # 24 character string

###
# Not fully implemented yet
# client --> hub
API message2
    event        : 'revoke_auth_token'
    fields:
        id:
           init  : undefined
           desc  : 'A unique UUID for the query'
        auth_token:
           init  : required
           desc  : 'an authentication token obtained using user_auth (24 character string)'
    desc         : """
Example:

Revoke a temporary authentication token for an account.
```
  curl -u sk_abcdefQWERTY090900000000: \\
    -d auth_token=BQokikJOvBiI2HlWgH4olfQ2 \\
    https://cocalc.com/api/v1/revoke_auth_token
  ==> {"event":"success","id":"9e8b68ac-08e8-432a-a853-398042fae8c9"}
```
"""
###


# client --> hub
API message2
    event       : 'metrics'
    fields:
        metrics :
            init : required
            desc : 'object containing the metrics'

API message2
    event       : 'start_metrics'
    fields:
        interval_s :
            init : required
            desc : 'tells client that it should submit metrics to the hub every interval_s seconds'