Config files

hydra.yaml

The archive's own settings.

Key	Is
name	The archive's name, asked by init
prefix	The id prefix every collection uses unless it has its own, asked by init
ftm	The hash of the FollowTheMoney schema the archive was made with; every export is stamped with it
defaults_off	The default rule files you switched off with hydra-ctl defaults off
subject	Optional. Names the organization the archive charts
search	Optional. Sets how far searches look when no flag says: all (the default), no-text (every field but free text) or names (names and ids)
format	The archive layout's version, written by init

.hydra/rules/

positions.yaml is your archive's own hierarchy, and defaults/positions.yaml holds the generic positions it builds on. Both are covered in Defining Hierarchies.

hints.yaml links icons, portraits, logos and badges to entities; see Images and badges.

.hydra/review/verdicts.yaml

Written by hydra-ctl review and hydra-ctl answer: one line per decision (this merge confirmed, that placement rejected). It is read on every build and travels with the archive.

hydra-ctl reset removes decisions, after backing the file up.

.hydra/schema/

The FollowTheMoney schema the archive uses, and Hydra's settings for it. These are background configuration: you can change them, but probably shouldn't. hydra-ctl defaults checks and restores params/, direction.yaml and the extensions/ files. It doesn't touch ftm/; to restore that, see open-hydra-schema.

Path	Is
ftm/followthemoney/	The FtM schema itself (types, properties, relationships)
ftm/config/	FtM's own config files
params/	One file per type (Person.param.yaml…)
direction.yaml	Which end of each relationship is the parent
extensions/collate.yaml	A helper for hierarchies and reviews
extensions/artifact.yaml	Hydra's extension types

params

Each param file says which fields decide that two records are the same entity (match), which fields keep them apart when they disagree (distinct), and which fields place a record under another (fold). A list in a param file replaces Hydra's defaults for that category.

direction.yaml

Says which end of each kind of relationship is the higher one: an Ownership's owner is above what it owns, a Membership's organization above its member. Some relationships are marked sideways (family, associates, lawyers), and those never make a hierarchy.

It is a helper for some annoying logic: leave it alone. It is also where edge_positions lives, the opt-in that fills a title in for a role-less Membership, Employment or Directorship.

artifact.yaml

extensions/artifact.yaml (with collate.yaml) holds extension types: Hydra's additions to FtM, such as the sources field on every entity and notes on relationships.