chore(flags): rename evaluation environments to evaluation contexts

[dmarticus]

Changes

NOTE: don't merge this yet; I just wanted to get the PR up, but I haven't made the necessary changes to the SDKs yet so hold your horses on actually changing the docs.

Renames the feature flag evaluation environments feature to "evaluation contexts" throughout the docs. The old name implied these were meant for deployment environments like "prod" or "staging", when they're actually meant for application contexts like "main-app", "marketing-site", or "checkout".

Changes

File renames:

• evaluation-environments.mdx → evaluation-contexts.mdx
• evaluation-runtimes-and-environments.md → evaluation-runtimes-and-contexts.md

Redirects added in vercel.json:

• /docs/feature-flags/evaluation-environments → /docs/feature-flags/evaluation-contexts
• /tutorials/evaluation-runtimes-and-environments → /tutorials/evaluation-runtimes-and-contexts

SDK parameter updates:

• Documents the new evaluation_contexts / evaluationContexts parameter
• Notes that legacy evaluation_environments / evaluationEnvironments is still supported for backward compatibility
• Adds version table showing which SDK versions support which parameter

Content updates across:

• Main evaluation contexts docs
• Creating feature flags docs
• SDK library docs (JS, Node, React Native, iOS, Android)
• API docs
• Tutorial
• Nav menu
• Team objectives

Checklist

• Words are spelled using American English
• PostHog product names are in title case. It's "Product Analytics" not "Product analytics". If talking about a category of product, use sentence case e.g. "There are a lot of product analytics tools, but PostHog's Product Analytics is the best"
• Titles are in sentence case
• Feature names are in sentence case. It's "Click here to create a trend insight" not "... create a Trend Insight" and so on.
• Use relative URLs for internal links
• If I moved a page, I added a redirect in vercel.json

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Review	Updated (UTC)
posthog	Ready	Preview	Jan 9, 2026 0:46am

[dustinbyrne]

👍 👍