Change log

All notable changes to the LaunchDarkly Erlang/Elixir SDK will be documented in this file. This project adheres to Semantic Versioning.

3.9.0 (2026-02-09)

Features

Support combining multi-contexts using ldcontext:new_multi_from. (#167) (7c9f934), closes #126

Bug Fixes

Fix an issue where <<kind>> would be included in the list of context kinds when kind was binary. (#168) (8cdee5c)

3.8.1 (2025-11-12)

Bug Fixes

Handle connection errors during read operations. (#163) (5838c2b)
Handle redis errors during mutations. (#165) (9dbe853)
Prevent uninitialized SDK warning in daemon mode. (#162) (0961922)
Redact SDK in gen_server descriptions and network errors. (#166) (3a4e005)

3.8.0 (2025-08-08)

Features

Update minimum OTP version to 24. (82f0e77)

Bug Fixes

Fix issue where sometimes a dropped stream would not reconnect. (82f0e77)

3.7.2 (2025-06-25)

Bug Fixes

Fix an issue with rollouts with a missing attribute. (#153) (a94ed9c), closes #152

3.7.1 (2025-06-03)

Bug Fixes

Change certifi dependency to a minimum version. (#150) (b1a91c0), closes #149

3.7.0 (2025-05-08)

Features

Inline context for custom events (#147) (1cd2357)

3.6.0 (2025-03-17)

Features

Add support for setting the redis username when using redis persistence. (#142) (c37fefd)
Update certifi to 2.14.0 (#144) (69771cf)

3.5.0 (2024-11-07)

Features

Updates shotgun version to 1.1.0 release (#139) (52dafc3)

3.4.0 (2024-10-24)

Features

Add support for client-side prerequisite events. (167308a)
Add support for client-side visibility for all_flags_state. (167308a)
Use ets for last-known server-time. (#136) (568ac51)

3.3.1 (2024-09-23)

Bug Fixes

Add mising events_uri type to options (#133) (65bb39c)

3.3.0 (2024-05-20)

Features

add tlsv1.3 to default cipher suites (#128) (4074483)

3.2.0 (2024-03-14)

Features

Always inline contexts for feature events (#119) (e5c6cc4)
Redact anonymous attributes within feature events (#120) (d334861)

3.1.0 (2024-01-04)

Features

For otp 25+ use public_key:cacerts_get for the default certificate list. (#114) (b7065aa)

Bug Fixes

Make gun open errors explicitly into temporary failures (#118) (fc70445)

3.0.4 (2023-12-04)

Bug Fixes

handle already_started when starting instance (#111) (5e181d4)

3.0.3 (2023-11-17)

Bug Fixes

Allow Elixir projects to read flags from a local file (#106) (c290599)

3.0.2 (2023-11-16)

Bug Fixes

Update certifi dependency to 2.12.0 (b0c5e56)

3.0.1 (2023-09-26)

Bug Fixes

Fix arithmetic error in stream re-connection logic. (#104) (416af68)

3.0.0 (2023-09-14)

Version 3.0 requires Gun 2.x. There are no changes to the Erlang SDK API or functionality. However, version 3.0 now requires Gun 2.x.

If your application depends directly on Gun, or if you have other dependencies that use Gun, then you must ensure that they work with Gun 2.x.

⚠ BREAKING CHANGES

Upgrade to support Gun 2.x (#99)

Features

Upgrade to support Gun 2.x (#99) (f15bf4d)

2.1.2 (2023-08-24)

Bug Fixes

Changes for OTP 26. (#93) (5f40282)

Changed

Update to eredis version 1.7.1.

[2.1.1] - 2023-08-02

Fixed:

Fixed ldclient_instance:options() to include new redis_tls option. Only specs affected.

[2.1.0] - 2023-08-01

Added:

A new configuration option, redis_tls, for configuring TLS settings for redis. When this option is omitted Redis will not use TLS. When specified it should contain a list of ssl:tls_option(). These options will be forwarded to eredis.

[2.0.5] - 2023-06-12

Changed:

Upgraded yamerl to version 0.10.0.

[2.0.4] - 2023-06-05

Fixed:

Remove error log message associated with debugging redis initialization state.

[2.0.3] - 2023-05-30

Fixed:

Add missing boolean() type to the ldclient_context:attribute_value() definition.

[2.0.2] - 2023-05-26

Fixed:

Fixed an issue that would prevent using values from redis for variation or all_flags_state calls before client initialization was complete. After this change if the erlang SDK is using an initialized redis prefix, then it will be able to evaluate against that store before initialization is complete. Note that the SDK did not previously store the $inited key used when detecting that a store is initialized, so the store will need updated by this SDK version (or newer) at least once before it would be considered initialized.

[2.0.1] - 2023-05-04

Fixed:

Fixed an issue where invalid contexts would generate events resulting in a crash in the event server.

[2.0.0] - 2023-02-22

The latest version of this SDK supports LaunchDarkly's new custom contexts feature. Contexts are an evolution of a previously-existing concept, "users." Contexts let you create targeting rules for feature flags based on a variety of different information, including attributes pertaining to users, organizations, devices, and more. You can even combine contexts to create "multi-contexts."

For detailed information about this version, please refer to the list below. For information on how to upgrade from the previous version, please read the migration guide.

Added:

Added a new module, ldclient_context, which defines the new "context" model.
All SDK methods that took an ldclient_user:user() now accept an ldclient_context:context() as well.
Added ldclient_flagbuilder:if_match/4, ldclient_flagbuilder:if_not_match/4, ldclient_flagbuilder:and_match/4, and ldclient_flagbuilder:and_not_match/4 which allow creating rules targeting specific context kinds using ldclient_testdata.

Changed (breaking changes from 1.x):

The secondary meta-attribute, which previously affected percentage rollouts, no longer exists. If you set an attribute with that name in ldclient_context:context(), it will simply be a custom attribute like any other.
Evaluations now treat the anonymous attribute as a simple boolean, with no distinction between a false state and an undefined state.
The binary() values in private_attributes in the configuration map now represent attribute references. If an attribute name had started with a /, then that will need to be escaped. For instance /myAttribute would now reference an attribute named myAttribute not an attribute named /myAttribute. The attribute reference would need to be updated to the escaped form /~1myAttribute.
ldclient_flagbuilder:variation_for_all_users has been replaced with ldclient_flagbuilder:variation_for_all and now applies to contexts.
ldclient_flagbuilder:variation_for_user has been replaced with ldclient_flagbuilder:variation_for_context and requires a context kind to be provided.
user_keys_capacity has been replaced with context_keys_capacity in the option configuration map.

Changed (behavioral changes):

The SDK can now evaluate segments that have rules referencing other segments.
Analytics event data now uses a new JSON schema due to differences between the context model and the old user model.

Removed:

Removed the secondary meta-attribute in ldclient_user:user().
The ldclient:alias method no longer exists because alias events are not needed in the new context model.
The inline_users_in_events option no longer exists because it is not relevant in the new context model.

[1.6.0] - 2023-01-30

Added:

application option, for configuration of application metadata that may be used in LaunchDarkly analytics or other product features. This does not affect feature flag evaluations.

ldclient:start_instance("sdk-key", #{
  application => #{
    id => <<"my-app-id">>,
    version => <<"my-app-version">>
  }
})

Added support for using server time, from response headers, when determining if debug events should be sent.

Changed:

Updated jitter/backoff implementation to be consistent with other SDK implementations.
Upgraded lru to version 2.4.0.
Upgrade certifi to version 2.10.0.
Removed dependency on backoff.

Fixed:

Fixed an issue where the SDK did not handle deleted flags/segments correctly in combination with evaluation of all flags.
Allow for track data to be null.

[1.5.0] - 2022-06-23

Changed:

Updated certifi to 2.9.0.
Updated shotgun to 0.5.3. This should obviate the need to override shotgun in mix.exs for Elixir projects.

Fixed:

Updated URI parsing to work with OTP 25. Removing the usage of http_uri:parse and replacing it with uri_string:parse.

[1.4.0] - 2022-04-20

Added:

ldclient:all_flags_state/3 to be used instead of ldclient:all_flags_state/1 or /2 if you are passing flag data to the front end for use with the JavaScript SDK. It preserves some flag metadata that the front end requires in order to send analytics events correctly. It does NOT yet support selecting client-side-enabled flags.
ldclient_testdata is a new way to inject feature flag data programmatically into the SDK for testing—either with fixed values for each flag, or with targets and/or rules that can return different values for different users. Unlike the file data source, this mechanism does not use any external resources, only the data that your test code has provided.
Support for the SDK test harness.

Fixed:

An issue with handling firstName and lastName in rules. The SDK uses first_name and last_name atoms for these fields and there was an issue with when the attribute names were converted. Now name conversion for attributes are done after evaluation and processing of private attributes.
ldclient:track and ldclient:tack_metric will not allow for types other than map() to be used for data.
The SDK was sending identify events for users with an empty key when it should not.
The SDK would send duplicate events for a user which had been identified and then was noticed by a feature evaluation. Now the event will be de-duplicated correctly within the LRU cache timeout.
Rule matches against dates in the user object, which could not be parsed, would cause evaluation to fail and return the default value. Now they will correctly result in the rule not matching instead.
The configuration was not trimming trailing / from URLs.

Changed:

Event fields which contained false or null will not generally be omitted from events for compactness.
Clarifications to documentation.

[1.3.2] - 2021-12-30

Fixed:

The file file_auto_update feature was not working correctly. If the flag files did not contain any changes between polling intervals, then the file system watcher would crash. (Thanks, matt-glover!)

[1.3.1] - 2021-11-09

Fixed:

Updated the options() typings for ldclient_instance:start to include missing configuration options. These included redis configuration, ld relay configuration, cache ttl, file data source configuration, and the http options. This is not a functionality change, but will correct issues reported by the dialyzer.

[1.3.0] - 2021-11-03

Added:

Support for configuring HTTP options. Including:
- The ability to specify custom headers.
```
 ldclient_config:parse_options("sdk-key", #{
   http_options => #{
       custom_headers => [
           {"Basic-String-Header", "String"},
           {"Binary-String-Header", "Binary"}
       ]}
   }),
```
- The ability to specify a custom connect timeout.
```
ldclient_config:parse_options("sdk-key", #{
    http_options => #{
        connect_timeout => 2000
    }
}),
```
- The ability to specify a custom TLS configuration. The default behavior for OTP is to use verify_none for TLS verification. If no configuration is specified, then the SDK will inherit this behavior.
```
ldclient_config:parse_options("sdk-key", #{
    http_options => #{
        %% This is a list of tls_client_options()
        %% https://www.erlang.org/doc/man/ssl.html#type-tls_client_option
        tls_options => ldclient_config:tls_basic_options()
    }
}),
```
- A number of TLS configuration helpers. A full TLS configuration can be specified, but these methods provide a number of basic configurations.
  - ldclient_config:tls_basic_options() -> [ssl:tls_client_option()]
    Create a basic TLS configuration which will try to use a default location for certificate authority store. If that store is not present, then instead the configuration will use a certifi store which is a Rebar3 dependency.
  - ldclient_config:tls_basic_linux_options() -> [ssl:tls_client_option()] Create a basic TLS configuration which will use a default location for a certificate store. If the store is not present, then it will produce an error.
  - ldclient_config:tls_ca_certfile_options(CaStorePath :: string()) -> [ssl:tls_client_option()] Create a basic TLS configuration with the specified certificate store. If the store is not present, then it will produce an error.
  - ldclient_config:with_tls_revocation(Options :: [ssl:tls_client_option()]) -> [ssl:tls_client_option()] Decorate a configuration with revocation checks. Currently revocation checks are not cached in OTP, so this will result in additional requests for each HTTP request.
  - ldclient_config:tls_basic_certifi_options() -> [ssl:tls_client_option()] Create a basic TLS configuration which will use the certifi store specified in the Rebar3 dependencies.

[1.2.0] - 2021-10-18

Added:

The SDK now supports the ability to control the proportion of traffic allocation to an experiment. This works in conjunction with a new platform feature now available to early access customers.
The SDK now supports the ability to read flags from a file.

[1.1.3] - 2021-09-27

Fixed:

When a rule was missing both the rollout and the variation, and that rule was matched, then variation 0 would be returned instead of the default value.
When a fall-through was missing both a rollout and a variation, then null would be returned instead of the default value.

[1.1.2] - 2021-09-13

Fixed:

The SDK now forces connections to use HTTP/1.1 instead of the newer HTTP/2 protocol as an underlying dependency does not yet support HTTP/2. This change does not impact current behavior as LaunchDarkly’s servers do not yet accept requests with HTTP/2; however, this SDK change ensures operational continuity when LaunchDarkly’s services enable HTTP/2 compatibility.
The SDK is more resilient when opening an SSE connection, processing events from the stream, and evaluating feature flags.

[1.1.1] - 2021-08-06

Changed:

Updated the eredis dependency to version 1.4.0. (Thanks, jeffgrunewald!)
Updated the jsx dependency to version 3.1.0. (Thanks, bitwalker!)
Updated the uuid dependency to version 2.0.2. (Thanks, jeffgrunewald!)
Expanded test coverage to include OTP 24.

[1.1.0] - 2021-05-06

Added:

ldclient:alias/2 and ldclient:alias/3 functions. These can be used to associate two user objects for analytics purposes with an alias event.

[1.0.1] - 2021-02-23

Changed:

Removed internal storage files from generated documentation.

[1.0.0] - 2021-02-22

Initial supported release of the SDK.

Added:

Added Redis feature store.
Added LDD mode.
Reload in-memory flag data when storage server fails.

Changed:

Parse flags and segments before in-memory storage.
Updated the default base URL to sdk.launchdarkly.com.
Events URL path from api/events/bulk to /bulk.
Renamed ldclient_settings to ldclient_config.
Renamed ldclient:track_with_metric to ldclient:track_metric.
Improved generated documentation.

Fixed:

Ignore path in streaming put events.

Removed:

Removed ldclient_settings.
Removed ldclient:track_with_metric.

[1.0.0-beta4] - 2020-08-27

Changed

Updaters now initialize asynchronously.
Updated shotgun from 0.4.0 to 0.5.0.

Fixed

Fixed GenServer crash on socket close in handle_cast in ldclient_event_dispatch_httpc.erl.
Fixed network timeout on initial connection.
Fixed restarting updates after a crash.
Fixed updater initialization state bugs.

[1.0.0-beta3] - 2020-05-18

Added

Added Erlang/OTP 23 image to CircleCI tests

Fixed

Fixed a bug preventing user first name and last name attibutes from properly being set
Fixed dates in tests to be RFC3339 compliant
Fixed dialyzer warning when application was started with offline option
Fixed SSE parsing bug in shotgun library with a workaround

[1.0.0-beta2] - 2020-02-20

Changed

Renamed eld to ldclient to better adhere to LaunchDarkly SDK naming conventions.
Changed the pkg_name to launchdarkly_server_sdk

[1.0.0-beta1] - 2020-02-12

Added

Added offline mode which stops the SDK making remote calls to LaunchDarkly and variation calls will then fall back to default values for your feature flags. You can do this by setting offline mode in the config map with the offline key.
Added ETag polling cache for If-None-Match on update requests.
The SDK now specifies a uniquely identifiable request header when sending events to LaunchDarkly to ensure that events are only processed once, even if the SDK sends them two times due to a failed initial attempt.
Added an initialized function which indicates whether the SDK is in offline mode or if the update processor has been initialized.

Changed

Return last variation when user bucket exceeds variation weight sum.
Client now checks initialization status when evaluating a variation or all flags.

[1.0.0-alpha4] - 2019-12-19

Added

Support for experimentation features. See eld:track_with_metric/4-5.

Fixed

Custom URI configuration is now consistent with other SDKs
Bucketing logic for custom non-string attributes is brought in line with the other SDKs

[1.0.0-alpha3] - 2019-10-29

Fixed

Dependencies specify tagged versions and use hex (thank you @hez)
eld:all_flags_state/2 now uses correct non-default instance (thank you @hez)
Streaming connection will now retry after initial request timeout

Removed

eld:evaluate/3-4 which were deprecated in the previous version
erlang.mk, Makefile now uses rebar3

[1.0.0-alpha2] - 2019-08-07

Added

Support for all server side LaunchDarkly events
eld:variation/3-4 and eld:variation_detail/3-4 functions to replace eld:evaluate/3-4 to reflect the naming convention
Feature to inline users inside events
Feature to define global private user attributes, including making all user attributes private

Fixed

Events POST URI, it no longer gets HTTP 405 Method Not Allowed error

Deprecated

eld:evaluate/3-4 will be removed in a future release

Missing

Polling support
Known issues for some edge case error conditions, and other minor missing features

[1.0.0-alpha1] - 2019-07-24

Added

Initial public release
Support for streaming and evaluations

Missing

Events don't pass integration tests
Polling support
Other known issues and minor missing features

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Change log

3.9.0 (2026-02-09)

Features

Bug Fixes

3.8.1 (2025-11-12)

Bug Fixes

3.8.0 (2025-08-08)

Features

Bug Fixes

3.7.2 (2025-06-25)

Bug Fixes

3.7.1 (2025-06-03)

Bug Fixes

3.7.0 (2025-05-08)

Features

3.6.0 (2025-03-17)

Features

3.5.0 (2024-11-07)

Features

3.4.0 (2024-10-24)

Features

3.3.1 (2024-09-23)

Bug Fixes

3.3.0 (2024-05-20)

Features

3.2.0 (2024-03-14)

Features

3.1.0 (2024-01-04)

Features

Bug Fixes

3.0.4 (2023-12-04)

Bug Fixes

3.0.3 (2023-11-17)

Bug Fixes

3.0.2 (2023-11-16)

Bug Fixes

3.0.1 (2023-09-26)

Bug Fixes

3.0.0 (2023-09-14)

⚠ BREAKING CHANGES

Features

2.1.2 (2023-08-24)

Bug Fixes

Changed

[2.1.1] - 2023-08-02

Fixed:

[2.1.0] - 2023-08-01

Added:

[2.0.5] - 2023-06-12

Changed:

[2.0.4] - 2023-06-05

Fixed:

[2.0.3] - 2023-05-30

Fixed:

[2.0.2] - 2023-05-26

Fixed:

[2.0.1] - 2023-05-04

Fixed:

[2.0.0] - 2023-02-22

Added:

Changed (breaking changes from 1.x):

Changed (behavioral changes):

Removed:

[1.6.0] - 2023-01-30

Added:

Changed:

Fixed:

[1.5.0] - 2022-06-23

Changed:

Fixed:

[1.4.0] - 2022-04-20

Added:

Fixed:

Changed: