[eli-r-ph]

💡 Motivation and Context

RequestContext sets default properties for every event in a request, but not capture options. The other v1 server SDKs let a request context set options too (posthog-python set_context_option, posthog-go RequestContext.Options, posthog-node context options), so a request can, for example, turn on cookieless_mode for all its events.

Changes

• RequestContext::option(key, value) sets a capture option for every event in the context, including exceptions from exception_options or the scoped context.
• The context fills an option only when the event leaves it unset: missing or null. An option the event sets wins, as with properties. For exceptions, the last value set for a key decides.
• PostHogLayer keeps the options of a RequestContext the application puts in the request extensions, as it keeps its identity and properties.
• A context process_person_profile replaces the false that Event::new_anon sets for a personless event, so the personless default is the lowest layer, as in posthog-python and posthog-go.
• README, migration guide and a minor changeset describe it; the public API snapshot gains the new method.

💚 How did you test it?

• test_request_context: the explicit-context test covers a filled option, an event option that wins, and a null event option the context fills; the scoped test checks the option on queued, batch and exception events on the wire. Both fail without the change.
• A unit test checks exception_options keeps the caller's options and fills only unset ones, including a key set and then cleared with null; it fails without the change.
• test_tower: an application context option reaches the handler's events; it fails without the change.
• test_request_context: a context process_person_profile: true reaches a personless event, and an event's own false still wins; it fails without the change.
• cargo test --all-features (618 passed; 619 with fix!: fill a request context $set key by key and let the context beat flag-event defaults #316) and --no-default-features --features error-tracking,tls (479 passed), cargo clippy --tests -- -D warnings (with and without mcp), cargo fmt -- --check, scripts/check-public-api.sh.

📝 Checklist

• All commits are signed (see Commit signing)
• I reviewed the submitted code.
• I added tests to verify the changes.
• I updated the docs if needed.
• No breaking change or entry added to the changelog.

If releasing new changes

• Ran sampo add to generate a changeset file

🤖 Generated with Claude Code

[marandaneto]

Automated advisory code review.

[turnipdabeets]

LGTM, the shape matches set_context_option in Python and RequestContext.Options in Go. One non-blocking suggestion inline.