Release Notes · fhir

0.21.0 Mar 15, 2026

Breaking change: remove r4 and r4b to fit in hex.pm size limit (probably due to recent change https://github.com/hexpm/hex_core/commit/4383e1b08aaf7d6dd325154d02f91e37f55b16b4, modules need to be reorganized at some point for package size and compilation/LSP speed)
Add custom types for complex extensions
Add primitive extensions
Add r4us with us core extensions
Generate r4usp, but not publish due to size limit

Breaking change: integer64 from Int to String in Gleam, as integer64 is sent as string in JSON, and is relatively uncommon, R5 only
Breaking change: remove unused SpInclude with _include and _revinclude from resource search params
Add search_any in clients, which takes a flexible (includes, modifiers, prefixes, etc.) but not necessarily correct String rather than statically typed search params
Add operation_any in clients, which similarly lets user choose operation name and parameters

Gleam types for FHIR data types and resources
JSON encoder and to_json functions
Enums for valuesets with required binding
Sans-io request/response for Create, Read, Update, Delete, Search
Search parameter types for each resource, but basic params only
Client layers over sans-io for httpc and rsvp
Supports R4, R4B, R5
Parses many valid FHIR JSON examples, but does not guarantee json -> encode -> to_json roundtrip will output same json as original, in particular there is a loss of implicit precision in decimal types, contrary to FHIR spec. At some point the decimal type will change, which will be a breaking change
Uses String for Date and DateTime, which will at some point change to a real time type in a breaking change
No primitive extensions support, so primitive elements will change in some undecided way
This is an initial release with various problems, so there could be breaking changes in any module

MAJOR - incompatible API changes

MINOR - backward-compatible functionality added

PATCH - backward-compatible bug fixes

Gleam fhir is a work in progress, tracking todo items at https://github.com/PotatoEMR/gleam-fhir/issues, if anything is incorrect, missing, or hard to use, please add an issue.