Client API Builder generates HTTP client methods from a declarative route DSL. It infers HTTP methods from route names, builds query strings and request bodies, and supports nested routers, configurable retries, and streaming responses to files or IO. SSL verification, base URL scheme checks, and path traversal protection are on by default. Optional ActiveSupport integration adds instrumentation and request logging.

Streaming tools for CSV files too big or too broken to load into memory. Compare two sorted files into create, update and delete actions, sort with an external merge sort, transform and extend rows in batches, and build reports from Ruby objects. Detects separators, byte order marks and encodings, and ships command line tools that pinpoint malformed rows, diff, grep, split and validate CSV files.

Dynamic Active Model automatically discovers database schemas and creates ActiveRecord models without manual class definitions. It detects and configures relationships (belongs_to, has_many, has_one, has_and_belongs_to_many) based on foreign keys and constraints, handles dangerous attribute names, supports model extensions, and includes a CLI tool for interactive database exploration.

Easy way to configure what data is mapped between models

Declare once how fields map from one object to another, and Mappable compiles it into plain Ruby methods that copy the data both ways at close to hand-written speed. Rename fields, combine several into one (first_name + last_name -> name) and split them back out, and skip fields with conditions on the source, the destination or the mapping itself. Works with any objects that have getters and setters: Structs, ActiveRecord models, plain Ruby classes.

Declare typed attributes and Schema turns incoming hashes, JSON and CSV rows into Ruby objects. Values are coerced to integers, floats, booleans, dates, times, arrays and hashes, and bad input is recorded as parsing errors instead of raised. Supports nested has_one/has_many associations, polymorphic types chosen by a type field, CSV header mapping, and ActiveModel validations.

Easy way to normalize attributes