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This document describes how we're currently translating the process of filling out a web form into YAML, a human-readable data serialization format.

This schema is now fairly concrete in that it's deployed to several production systems. To suggest a change, please file a ticket to (the issue tracker) and allow time for it to be discussed with implementors prior to making changes.

You can jump to the examples if you just want a quick reference.

Top-level attributes

The top level of a member's contact schema includes only two fields: bioguide and contact_form.

bioguide is the legislator's assigned Bioguide ID which can be used to connect this data to other data sources in the unitedstates project.

contact_form is a nested hash of the pertinent details of successfully filling out and validating receipt of the member's contact form.

Contact form fields


The HTTP method used to submit the form in all caps, most likely GET or POST


The URL the form should submit to. An empty string ('') can be used to represent the URL the form is located at, but otherwise, this should be an absolute URL like, rather than /unitedstates/congress-contact, even if that is what appears in the form.


A list of the steps that make up a successful submission of the form. Steps are a subset of Capybara methods, one of:

  • visit: The act of navigating to a given url.
  • find: Locating a selector on the page, an indication that no further steps should be executed until the selector is present and visible.
  • fill_in: Entering text into a text input or textarea.
  • select: Choosing a value from a select list. If this value isn't found, choose an option with the text matching the value of value in the YAML file. (This is so that we can choose options by text, since some forms do not include value attributes.)
  • check: Ticking a checkbox input.
  • uncheck The opposite of check.
  • choose Ticking a specific item in a set of radio buttons.
  • click_on Clicking a link or button, most likely to submit a form.
  • wait: Experimental. Indicates that the specified time interval should pass before proceeding.
  • javascript: Execute some javascript on current page


A basic description of what a successful HTTP response looks like. This is a hash of headers and body content:

  • headers
    Any standard HTTP header can be expected here, but most implementations won't need this information. status is provided as an example.
    • status: The numeric http code the response should match, eg 200
  • body
    • contains: A plain string that should be present in the body. This is preferred over matches unless a more complex rule is necessary.
    • matches: A regular expression bounded by plain string delimiters ("") for portability. It's preferable to provide a pattern (if one is needed) that can be matched case-insensitively and on one line.


Failure, in general, can be assumed in the absence of success. But, there are some conditions where feedback can be provided to the 'user' to correct an error. Address validation and CAPTCHA failure are the two prime examples of scenarios in which a retry could be prudent.

retry should be specified as an array of retry conditions, including a reason, a selector or contains value, and a resubmit array, containing:

  • reason
    An identifier of the failure type. Currently, captcha is the only specified value.
  • selector
    A css selector whose presence indicates this specific type of failure.
  • content
    Text whose presence indicates this specific type of failure.
  • resubmit
    A list of field values (such as $CAPTCHA) that need to be resubmitted. The expectation is that clients will redraw whatever interface is necessary using the definition of that value's field in the form YAML.

Types of steps


The value of a visit step is just a string url.


The selector of a find step is just a string CSS selector which should be found on the page (and should be visible) before proceeding to execute more steps.

The value of a find step is optional, and it may specify the markup contained in the element that is required for this element to be found.

The options attribute for the find step may be specified as wait: x, where x is an integer number of seconds. If the element is not found within this number of seconds, the form fill will be abandoned and should return an error to the caller.

The within_frame attribute is optional and consists of a string denoting the selector of an iframe on the page. If present, the find step will be executed in the context of the matching iframe.


The value of a fill_in step can be a single field, or a list of hashes defining a batch of fields to fill in at once, but should be defined as a list either way. Each hash describes a form field by a few attributes, many of which are common to most steps:

  • name: The name HTML attribute of the field to be filled out.
  • selector: It's expected that a specific CSS selector will be provided in addition to the name field, because it's possible that more than one field with the same name (email, for example) may be present on the page.
  • value: Either a string value to enter into the form, or a 'variable' placeholder, such as $EMAIL. These placeholders are listed and explained in variables.yaml in the support folder of this repo. The leading dollar sign is used to help disambiguate these special values from an all-caps string value that might be intended to go directly into the form field.
  • required (ironically, optional): This field will be present if a field must be filled out with a value in order for the form to be valid.
  • options (fittingly, optional): This attributes meaning changes with value. If the value is one of the following, options can be specified accordingly:
    • $EMAIL: allows_plus: true or allows_plus: false, depending on if the form allows a plus sign in the email field.
    • max_length: This field will be present if a field has a maximum character length. This value should be a number. It's very useful where max length is only enforced server-side.
  • within_frame (optional): Consists of a string denoting the selector of an iframe on the page. If present, the fill_in step will be executed in the context of the matching iframe.

A note on CAPTCHAs

Contact forms may present a captcha challenge, which of course is difficult to deal with in an automated fashion. CAPTCHAs should be handled as fill_in fields with the variable $CAPTCHA_SOLUTION as the value. These fields should also describe a captcha_selector key for retrieving the captcha image and returning it to a solver of the implementer's choosing.

Google's new ReCAPTCHAs have special syntax. In this case, the captcha_selctor should be the iframe containing the ReCAPTCHA. The google_recaptcha option should be set to true as well. See here for an example.


These steps can also either list one or many hashes. It should be expected that a single form can be filled out with many steps until a click_on step is encountered, at which time the form should be submitted.

The attributes of these steps are the same as those of fill_in, and should be treated as such with the exception of value. In a checkbox or radio button context, value describes the actual value attribute of the checkbox that should be checked/unchecked/chosen, in case several have the same name attribute.

The within_frame attribute is optional and consists of a string denoting the selector of an iframe on the page. If present, the check/uncheck/choose step will be executed in the context of the matching iframe.


Like the other input-related steps, selects can list either one or many hashes. Attributes are the same as fill_in with the addition of options, a list of the possible options which can be selected. If the value attributes of the select's options are obscure abbreviations or otherwise non-human-readable, the value of options can be a hash where the key is the text that appears in the select box when the option is selected, and the value is the option's value attribute. In cases where the options are common across several members' forms, a constant may be used as a placeholder. Available constants are listed in constants.yaml in this repository. Currently the only available constants are a list of the postal codes of the 50 US states plus DC, and the full list of states and territories. The constants encountered in options lists comprise the keys in constants.yaml so the resulting constants hash can be indexed directly with them.

The within_frame attribute is optional and consists of a string denoting the selector of an iframe on the page. If present, the select step will be executed in the context of the matching iframe.


A click_on step terminates the preceding list of input-related steps, by submitting the web form. It is a list containing a hash with only two possible keys: selector and value. selector is the CSS selector for finding the button or link to click, and value is the HTML value attribute if present, both to disambiguate and for the benefit of clients which may be POSTing directly instead of using a headless browser, though this is not recommended. selector is the only attribute you must provide/should expect to be guaranteed.

The within_frame attribute is optional and consists of a string denoting the selector of an iframe on the page. If present, the click_on step will be executed in the context of the matching iframe.


This step should be considered experimental and subject to change

This is not part of the capybara command set, but is in place at least temporarily for the benefit of javascript-capable clients. It may get folded into find at a later date. It indicates the integer number of seconds that should be waited before performing the next action.

This step is not to be confused with the wait option under find, which denotes the maximum time that should pass while waiting for an element to appear.


The value key determines what javascript to execute in this step. Note that this instruction should only be used sparingly. It is better to mimic user behavior as closely as possible, but if there is no way to proceed with normal ux steps, this instruction may be used.

The within_frame attribute is optional and consists of a string denoting the selector of an iframe on the page. If present, the javascript step will be executed in the context of the matching iframe.


To put it all together, let's do a google search for our last name as an example. For some reason, this search requires that you fill out a captcha:

bioguide: #(well, it's google, so there isn't one)
  method: GET
    - visit:
    - fill_in:
      - name: q
        selector: "#gbqfq"
        value: $NAME_LAST
        required: Yes
      - name: recaptcha_response_field
        selector: "#recaptcha_response_field"
        captcha_selector: img
        captcha_id_selector: "#recaptcha_challenge_field"
        value: $CAPTCHA_SOLUTION
        required: Yes
    - click_on:
      - selector: "#gbqfba"
      contains: "results ("
    - reason: captcha
      contains: "captcha was invalid"

Here is a list of examples that may help you:

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