Optimizely

REST API at api.optimizely.com/v2. Resources: projects, experiments, features, audiences, environments, results. GET /v2/experiments lists experiments for a project. Feature flags: list via GET /v2/features. Results API: GET /v2/experiments/{id}/results returns statistical analysis (confidence interval, p-value, improvement). SDK datafile: GET https://cdn.optimizely.com/datafiles/{sdk_key}.json returns current feature configuration for local SDK initialization.

Standard HTTP status codes with JSON error bodies. 401 for invalid token, 403 for insufficient project access, 400 for invalid request params. SDK evaluation errors are in-process (no network calls after initialization); SDK handles fallback to control variant on error. Results API returns 202 (async) for recent experiments with insufficient data. Rate limits documented (100 req/min for REST). Optimizely CDN SLA: 99.9%. Status at status.optimizely.com.

Optimizely is an enterprise-grade experimentation platform for A/B testing, multivariate experiments, feature flags, and personalization — used by major brands (eBay, IBM, HP). Its Feature Experimentation product provides server-side SDKs (Python, Java, Node.js, Go, Swift, etc.) for flag evaluation with local bucketing (no per-request API call) and a REST API for managing experiments and reading results. For agents, the server-side SDK pattern is most relevant: initialize once with the datafile, then evaluate flags locally at request time — zero latency overhead. REST API handles experiment management and reporting. Enterprise access model creates friction for smaller teams. Confidence is docs-derived.

Bearer token auth via Authorization: Bearer header. Tokens from Optimizely Account Settings → API Access. Project-scoped access; one token can manage all projects in the account. SDK key (separate from API token) used for CDN datafile access — no auth required for the datafile endpoint (publicly accessible by design). OAuth2 available for partner integrations. Enterprise accounts may use SSO.

docs.developers.optimizely.com provides REST API reference, SDK guides for all supported languages, experiment setup workflows, and results interpretation. Documentation quality is high and well-maintained. Getting started with Optimizely Feature Experimentation is faster than the web experimentation product (more accessible pricing). Enterprise sales process required for web experimentation tier. Community support via Optimizely Community Forum.