Beware: The API is Huge!!
Below is the list of all the "types" of objects returned by the API v2.0+ :-
Note: v2.1 specific types are noted in a seperate box
Type | Field | Field Type
-------------------+------------------------------+----------------------
answers | answer_id | int, refers to an answer
| body | str (2)
| comments | array(comments)
| community_owned_date | date (1)
| creation_date | date
| down_vote_count | int
| is_accepted | bool
| last_activity_date | date
| last_edit_date | date (1)
| link | str (2)
| locked_date | date (1)
| owner | shallow_user (1)
| question_id | int, refers to a question
| score | int
| title | str
| up_vote_count | int
-------------------------------------------------------------------------
question | accepted_answer_id | int (1)
| answer_count | int
| answers | array(answers)
| body | str (2)
| bounty_amount | int (1)
| bounty_closes_date | date (1)
| closed_date | date (1)
| closed_reason | str (1)
| comments | array(comments)
| community_owned_date | date (1)
| creation_date | date
| down_vote_count | int
| favorite_count | int
| is_answered | bool
| last_activity_date | date
| last_edit_date | date (1)
| link | str (2)
| locked_date | date (1)
| migrated_from | migration_info (1)
| migrated_to | migration_info (1)
| owner | shallow_user (1)
| protected_date | date (1)
| question_id | int, refers to a question
| score | int
| tags | array(strs)
| title | str
| up_vote_count | int
| view_count | int
-------------------------------------------------------------------------
access_token | access_token | str
| account_id | int
| expires_on_date | date (1)
| scope | array(strs)
-------------------------------------------------------------------------
answer | answer_id | int, refers to an answer
| body | str (2)
| comments | array(comments)
| community_owned_date | date (1)
| creation_date | date
| down_vote_count | int
| is_accepted | bool
| last_activity_date | date
| last_edit_date | date (1)
| link | str (2)
| locked_date | date (1)
| owner | shallow_user (1)
| question_id | int, refers to a question
| score | int
| title | str
| up_vote_count | int
-------------------------------------------------------------------------
badge | award_count | int
| badge_id | int, refers to a badge
| badge_type | one of named, or tag_based
| description | str (2)
| link | str (2)
| name | str
| rank | one of gold, silver, or bronze
| user | shallow_user (1)
-------------------------------------------------------------------------
comment | body | str (2)
| comment_id | int, refers to a comment
| creation_date | date
| edited | bool
| link | str (2)
| owner | shallow_user (1)
| post_id | int, refers to a post
| post_type | one of question, or answer
| reply_to_user | shallow_user (1)
| score | int
-------------------------------------------------------------------------
error | description | str
| error_id | int, refers to an error
| error_name | str
-------------------------------------------------------------------------
event | creation_date | date
| event_id | the id of the object (answer, comment, question, or user) the event describes
| event_type | one of question_posted, answer_posted, comment_posted, post_edited, or user_created
| excerpt | str (2)
| link | str (2)
-------------------------------------------------------------------------
filter | filter | str
| filter_type | one of safe, unsafe, or invalid
| included_fields | array(strs)
-------------------------------------------------------------------------
inbox_item | answer_id | int, refers to an answer (1)
| body | str (2)
| comment_id | int, refers to a comment (1)
| creation_date | date
| is_unread | bool
| item_type | one of comment, chat_message, new_answer, careers_message, careers_invitations, meta_question, post_notice, or moderator_message
| link | str (2)
| question_id | int, refers to a question (1)
| site | site (1)
| title | str
-------------------------------------------------------------------------
info | answers_per_minute | decimal
| api_revision | str
| badges_per_minute | decimal
| new_active_users | int
| questions_per_minute | decimal
| site | site
| total_accepted | int
| total_answers | int
| total_badges | int
| total_comments | int
| total_questions | int
| total_unanswered | int
| total_users | int
| total_votes | int
-------------------------------------------------------------------------
network_user | account_id | int
| answer_count | int
| badge_counts | badge_count
| creation_date | date
| last_access_date | date
| question_count | int
| reputation | int
| site_name | str
| site_url | str
| user_id | int, refers to a user
| user_type | one of unregistered, registered, moderator, or does_not_exist
-------------------------------------------------------------------------
user type | about_me | str (2) (1)
| accept_rate | int (1)
| account_id | int
| age | int (1)
| answer_count | int
| badge_counts | badge_count
| creation_date | date
| display_name | str
| down_vote_count | int
| is_employee | bool
| last_access_date | date
| last_modified_date | date (1)
| link | str (2)
| location | str (1)
| profile_image | str (2)
| question_count | int
| reputation | int
| reputation_change_day | int
| reputation_change_month | int
| reputation_change_quarter | int
| reputation_change_week | int
| reputation_change_year | int
| timed_penalty_date | date (1)
| up_vote_count | int
| user_id | int, refers to a user
| user_type | one of unregistered, registered, moderator, or does_not_exist
| view_count | int
| website_url | str (2) (1)
-------------------------------------------------------------------------
post | body | str (2)
| comments | array(comments)
| creation_date | date
| down_vote_count | int
| last_activity_date | date
| last_edit_date | date (1)
| owner | shallow_user (1)
| post_id | int, refers to a post
| post_type | one of question, or answer
| score | int
| up_vote_count | int
-------------------------------------------------------------------------
privilege | description | str (2)
| reputation | int
| short_description | str (2)
-------------------------------------------------------------------------
question | accepted_answer_id | int (1)
| answer_count | int
| answers | array(answers)
| body | str (2)
| bounty_amount | int (1)
| bounty_closes_date | date (1)
| closed_date | date (1)
| closed_reason | str (1)
| comments | array(comments)
| community_owned_date | date (1)
| creation_date | date
| down_vote_count | int
| favorite_count | int
| is_answered | bool
| last_activity_date | date
| last_edit_date | date (1)
| link | str (2)
| locked_date | date (1)
| migrated_from | migration_info (1)
| migrated_to | migration_info (1)
| owner | shallow_user (1)
| protected_date | date (1)
| question_id | int, refers to a question
| score | int
| tags | array(strs)
| title | str
| up_vote_count | int
| view_count | int
-------------------------------------------------------------------------
question_timeline | comment_id | int, refers to a comment (1)
| creation_date | date
| down_vote_count | int (1)
| owner | shallow_user (1)
| post_id | int, refers to a post (1)
| question_id | int, refers to a question
| revision_guid | str (1)
| timeline_type | one of question, answer, comment, unaccepted_answer, accepted_answer, vote_aggregate, revision, or post_state_changed
| up_vote_count | int (1)
| user | shallow_user (1)
-------------------------------------------------------------------------
reputation | link | str (2)
| on_date | date
| post_id | int, refers to a post
| post_type | one of question, or answer
| reputation_change | int
| title | str
| user_id | int, refers to a user
| vote_type | one of accepts, up_votes, down_votes, bounties_offered, bounties_won, spam, or suggested_edits
-------------------------------------------------------------------------
reputation_history | creation_date | date
| post_id | int, refers to a post (1)
| reputation_change | int
| reputation_history_type | one of asker_accepts_answer, asker_unaccept_answer, answer_accepted, answer_unaccepted, voter_downvotes, voter_undownvotes, post_downvoted, post_undownvoted, post_upvoted, post_unupvoted, suggested_edit_approval_received, post_flagged_as_spam, post_flagged_as_offensive, bounty_given, bounty_earned, bounty_cancelled, post_deleted, post_undeleted, association_bonus, arbitrary_reputation_change, vote_fraud_reversal, post_migrated, or user_deleted
| user_id | int, refers to a user
-------------------------------------------------------------------------
revision | body | str (2) (1)
| comment | str
| creation_date | date
| is_rollback | bool
| last_body | str (2) (1)
| last_tags | array(strs)
| last_title | str (1)
| post_id | int, refers to a post
| post_type | one of question, or answer
| revision_guid | str
| revision_number | int
| revision_type | one of single_user, or vote_based
| set_community_wiki | bool
| tags | array(strs)
| title | str (1)
| user | shallow_user
-------------------------------------------------------------------------
site | aliases | array(strs)
| api_site_parameter | str
| audience | str
| closed_beta_date | date (1)
| favicon_url | str
| icon_url | str
| launch_date | date
| logo_url | str
| markdown_extensions | array('MathJax',)
| name | str
| open_beta_date | date (1)
| related_sites | array(related_sites)
| site_state | one of normal, closed_beta, open_beta, or linked_meta
| site_type | one of main_site or meta_site, but new options may be added.
| site_url | str
| styling | styling
| twitter_account | str (1)
-------------------------------------------------------------------------
suggested_edit | approval_date | date (1)
| body | str (2) (1)
| comment | str
| creation_date | date
| post_id | int, refers to a post
| post_type | one of question, or answer
| proposing_user | shallow_user (1)
| rejection_date | date (1)
| suggested_edit_id | int, refers to a suggested_edit
| tags | array(strs)
| title | str (1)
-------------------------------------------------------------------------
tag | count | int
| has_synonyms | bool
| is_moderator_only | bool
| is_required | bool
| last_activity_date | date (1)
| name | str
| user_id | int, refers to a user (1)
-------------------------------------------------------------------------
tag_score | post_count | int
| score | int
| user | shallow_user
-------------------------------------------------------------------------
tag_synonym | applied_count | int
| creation_date | date
| from_tag | str
| last_applied_date | date (1)
| to_tag | str
-------------------------------------------------------------------------
tag_wiki | body | str (2) (1)
| body_last_edit_date | date (1)
| excerpt | str (1)
| excerpt_last_edit_date | date (1)
| last_body_editor | shallow_user (1)
| last_excerpt_editor | shallow_user (1)
| tag_name | str
-------------------------------------------------------------------------
top_tag | answer_count | int
| answer_score | int
| question_count | int
| question_score | int
| tag_name | str (2)
-------------------------------------------------------------------------
user | about_me | str (2) (1)
| accept_rate | int (1)
| account_id | int
| age | int (1)
| answer_count | int
| badge_counts | badge_count
| creation_date | date
| display_name | str
| down_vote_count | int
| is_employee | bool
| last_access_date | date
| last_modified_date | date (1)
| link | str (2)
| location | str (1)
| profile_image | str (2)
| question_count | int
| reputation | int
| reputation_change_day | int
| reputation_change_month | int
| reputation_change_quarter | int
| reputation_change_week | int
| reputation_change_year | int
| timed_penalty_date | date (1)
| up_vote_count | int
| user_id | int, refers to a user
| user_type | one of unregistered, registered, moderator, or does_not_exist
| view_count | int
| website_url | str (2) (1)
-------------------------------------------------------------------------
user_timeline | badge_id | int, refers to a badge (1)
| comment_id | int, refers to a comment (1)
| creation_date | date
| detail | str (2) (1)
| link | str (2)
| post_id | int, refers to a post (1)
| post_type | one of question, or answer
| suggested_edit_id | int, refers to a suggested_edit (1)
| timeline_type | one of commented, asked, answered, badge, revision, accepted, reviewed, or suggested
| title | str (1)
| user_id | int, refers to a user
Member Types The following types are not returned directly by any method, but are found as members on other types.
Type | Field | Field Type
-------------------+------------------------------+----------------------
badge_count | bronze | int
| gold | int
| silver | int
-------------------------------------------------------------------------
migration_info | on_date | date
| other_site | site
| question_id | int, refers to a question
-------------------------------------------------------------------------
related_site | api_site_parameter | str (1)
| name | str
| relation | one of parent, meta, or chat, but new options may be added.
| site_url | str (2)
-------------------------------------------------------------------------
shallow_user | accept_rate | int (1)
| display_name | str (1)
| link | str (2) (1)
| profile_image | str (2) (1)
| reputation | int (1)
| user_id | int, refers to a user (1)
| user_type | one of unregistered, registered, moderator, or does_not_exist
-------------------------------------------------------------------------
styling | link_color | str
| tag_background_color | str
| tag_foreground_color | str
-------------------------------------------------------------------------
v2.1 Specific fields
-------------------------------------------------------------------------
comment | body_markdown | str
-------------------------------------------------------------------------
notice | body | str (2)
| creation_date | date
| owner_user_id | int
-------------------------------------------------------------------------
notification | body | str (2)
| creation_date | date
| is_unread | bool
| notification_type | one of generic, profile_activity, bounty_expired, bounty_expires_in_one_day, badge_earned, bounty_expires_in_three_days, reputation_bonus, accounts_associated, new_privilege, post_migrated, moderator_message, registration_reminder, edit_suggested, or substantive_edit
| post_id | int, refers to a post (1)
| site | site
-------------------------------------------------------------------------
question | close_vote_count | int
| delete_vote_count | int
| notice | notice
| reopen_vote_count | int
| close_vote_count | int
| delete_vote_count | int
| notice | notice
| reopen_vote_count | int
-------------------------------------------------------------------------
site | high_resolution_icon_url | str (1)
-------------------------------------------------------------------------
answers | tags | array(strs)
-------------------------------------------------------------------------
account_merge | merge_date | date
| new_account_id | int
| old_account_id | int
-------------------------------------------------------------------------
answer | tags | array(strs)
-------------------------------------------------------------------------
post | link | str
-------------------------------------------------------------------------
top_tag | user_id | int, refers to a user
-------------------------------------------------------------------------
write_permission | can_add | bool
| can_delete | bool
| can_edit | bool
| max_daily_actions | int
| min_seconds_between_actions | int
| object_type | str
| user_id | int, refers to a user
-------------------------------------------------------------------------
Key:
(1) : may be absent
(2) : unchanged in unsafe filters
int : integer
str : string
bool : boolean
array(x) : an array of x
Note: All this info has been extracted from Stack Exchange API Docs... by this script.