Agent - 4.5.0
3 min
[4.5.0] - July 14, 2026
This release adds support for local (per-rule) holdouts and Feature Rollouts, delivered by upgrading the embedded go-sdk from v2.3.0 to v2.5.0. It builds on the global holdouts support introduced in 4.4.0.
New Features
- Local Holdouts Support (#464): Agent now supports local (per-rule) holdouts in addition to global holdouts, via go-sdk v2.5.0. Local holdouts target specific rules and are evaluated per-rule, after forced decisions and before audience/traffic checks. Held-out decisions return enabled: false, variationKey: "ho_off_key", and ruleKey set to the holdout identifier, with impression rule_type: "holdout". As with global holdouts, all decision logic is handled by go-sdk — no Agent code changes are required beyond updating the ProjectConfig test mock.
- Feature Rollout Support (#463): Via go-sdk v2.4.0, Agent now supports Feature Rollouts — a rule type combining Targeted Delivery with A/B test measurement capabilities.
Behavior Changes
These changes come from the go-sdk v2.4.0 → v2.5.0 upgrade:
- Decision event ID normalization: decision event campaign_id and entity_id fall back to experiment_id when empty, and variation_id serializes as null when non-numeric, for cross-SDK consistency.
- ODP identify guard: ODP identify events carrying only a single identifier are now blocked.
- Removed legacy flag-level holdout fields from datafile parsing.
Maintenance
- Add Dependabot to auto-update the go-sdk dependency (#458)
- Remove Coveralls from CI checks (#462)
- Add Agent developer documentation (#461)
- Fix Arnica security vulnerabilities (#460)
- Synchronize linters between go-sdk and agent (#457)
Dependencies
- Upgraded `github.com/optimizely/go-sdk/v2` from v2.3.0 to v2.5.0