diff --git a/.changeset/hungry-bears-march.md b/.changeset/hungry-bears-march.md
new file mode 100644
index 000000000..6aba01153
--- /dev/null
+++ b/.changeset/hungry-bears-march.md
@@ -0,0 +1,5 @@
+---
+'@segment/analytics-core': patch
+---
+
+Improve types for context and traits and fix SegmentEvent context type (node only ATM). Refactor context eventFactory to clarify.
diff --git a/packages/core/src/events/index.ts b/packages/core/src/events/index.ts
index 11ef064c3..d01ee7f9f 100644
--- a/packages/core/src/events/index.ts
+++ b/packages/core/src/events/index.ts
@@ -4,12 +4,14 @@ import { ID, User } from '../user'
 import {
   Integrations,
   EventProperties,
-  Traits,
+  CoreAnalyticsTraits,
   CoreSegmentEvent,
   CoreOptions,
+  CoreExtraContext,
 } from './interfaces'
 import { pickBy } from '../utils/pick'
 import { validateEvent } from '../validation/assertions'
+import type { RemoveIndexSignature } from '../utils/ts-helpers'
 
 interface EventFactorySettings {
   createMessageId: () => string
@@ -101,7 +103,7 @@ export class EventFactory {
 
   identify(
     userId: ID,
-    traits?: Traits,
+    traits?: CoreAnalyticsTraits,
     options?: CoreOptions,
     globalIntegrations?: Integrations
   ): CoreSegmentEvent {
@@ -117,7 +119,7 @@ export class EventFactory {
 
   group(
     groupId: ID,
-    traits?: Traits,
+    traits?: CoreAnalyticsTraits,
     options?: CoreOptions,
     globalIntegrations?: Integrations
   ): CoreSegmentEvent {
@@ -186,30 +188,42 @@ export class EventFactory {
    * Builds the context part of an event based on "foreign" keys that
    * are provided in the `Options` parameter for an Event
    */
-  private context(event: CoreSegmentEvent): [object, object] {
-    const options = event.options ?? {}
-    delete options['integrations']
+  private context(
+    options: CoreOptions
+  ): [CoreExtraContext, Partial<CoreSegmentEvent>] {
+    type CoreOptionKeys = keyof RemoveIndexSignature<CoreOptions>
+    /**
+     * If the event options are known keys from this list, we move them to the top level of the event.
+     * Any other options are moved to context.
+     */
+    const eventOverrideKeys: CoreOptionKeys[] = [
+      'userId',
+      'anonymousId',
+      'timestamp',
+    ]
 
-    const providedOptionsKeys = Object.keys(options)
+    delete options['integrations']
+    const providedOptionsKeys = Object.keys(options) as Exclude<
+      CoreOptionKeys,
+      'integrations'
+    >[]
 
-    const context = event.options?.context ?? {}
-    const overrides = {}
+    const context = options.context ?? {}
+    const eventOverrides = {}
 
     providedOptionsKeys.forEach((key) => {
       if (key === 'context') {
         return
       }
 
-      if (
-        ['integrations', 'anonymousId', 'timestamp', 'userId'].includes(key)
-      ) {
-        dset(overrides, key, options[key])
+      if (eventOverrideKeys.includes(key)) {
+        dset(eventOverrides, key, options[key])
       } else {
         dset(context, key, options[key])
       }
     })
 
-    return [context, overrides]
+    return [context, eventOverrides]
   }
 
   public normalize(event: CoreSegmentEvent): CoreSegmentEvent {
@@ -240,14 +254,17 @@ export class EventFactory {
       ...event.options?.integrations,
     }
 
-    const [context, overrides] = this.context(event)
+    const [context, overrides] = event.options
+      ? this.context(event.options)
+      : []
+
     const { options, ...rest } = event
 
     const body = {
       timestamp: new Date(),
       ...rest,
-      context,
       integrations: allIntegrations,
+      context,
       ...overrides,
     }
 
diff --git a/packages/core/src/events/interfaces.ts b/packages/core/src/events/interfaces.ts
index e2af6e7e9..0d8f0c7a1 100644
--- a/packages/core/src/events/interfaces.ts
+++ b/packages/core/src/events/interfaces.ts
@@ -16,8 +16,6 @@ export type JSONValue = JSONPrimitive | JSONObject | JSONArray
 export type JSONObject = { [member: string]: JSONValue }
 export type JSONArray = JSONValue[]
 
-export type Traits = Record<string, any>
-
 export type EventProperties = Record<string, any>
 
 export type Integrations = {
@@ -28,64 +26,126 @@ export type Integrations = {
 // renamed
 export interface CoreOptions {
   integrations?: Integrations
-  timestamp?: Date | string
-  context?: CoreAnalyticsContext
+  timestamp?: Timestamp
+  context?: CoreExtraContext
   anonymousId?: string
   userId?: string
-  traits?: Traits
+  traits?: CoreAnalyticsTraits
   // ugh, this is ugly, but we allow literally any property to be passed to options (which get spread onto the event)
   // we may want to remove this...
   [key: string]: any
 }
 
-interface CoreAnalyticsContext {
+/**
+ * Context is a dictionary of extra information that provides useful context about a datapoint, for example the user’s ip address or locale. You should only use Context fields for their intended meaning.
+ * @link https://segment.com/docs/connections/spec/common/#context
+ */
+export interface CoreExtraContext {
+  /**
+   * This is usually used to flag an .identify() call to just update the trait, rather than "last seen".
+   */
+  active?: boolean
+
+  /**
+   * Current user's IP address.
+   */
+  ip?: string
+
+  /**
+   * Locale string for the current user, for example en-US.
+   * @example en-US
+   */
+  locale?: string
+  /**
+   * Dictionary of information about the user’s current location.
+   */
+  location?: {
+    /**
+     * @example San Francisco
+     */
+    city?: string
+    /**
+     * @example United States
+     */
+    country?: string
+    /**
+     * @example 40.2964197
+     */
+    latitude?: string
+    /**
+     * @example -76.9411617
+     */
+    longitude?: string
+    /**
+     * @example CA
+     */
+    region?: string
+    /**
+     * @example 100
+     */
+    speed?: number
+  }
+
+  /**
+   * Dictionary of information about the current web page.
+   */
   page?: {
     /**
-     *  {@link https://github.com/segmentio/analytics.js-integrations/blob/2d5c637c022d2661c23449aed237d0d546bf062d/integrations/segmentio/lib/index.js#L151}
+     * @example /academy/
      */
     path?: string
+    /**
+     * @example https://www.foo.com/
+     */
     referrer?: string
+    /**
+     * @example projectId=123
+     */
     search?: string
+    /**
+     * @example Analytics Academy
+     */
     title?: string
+    /**
+     * @example https://segment.com/academy/
+     */
     url?: string
   }
 
   /**
-   *  {@link https://github.com/segmentio/analytics.js-integrations/blob/2d5c637c022d2661c23449aed237d0d546bf062d/integrations/segmentio/lib/index.js#L285}
+   * User agent of the device making the request.
    */
   userAgent?: string
 
   /**
-   * {@link https://github.com/segmentio/analytics.js-integrations/blob/2d5c637c022d2661c23449aed237d0d546bf062d/integrations/segmentio/lib/index.js#L286-L289}
-   */
-  locale?: string
-
-  /**
-   * {@link https://github.com/segmentio/analytics.js-integrations/blob/2d5c637c022d2661c23449aed237d0d546bf062d/integrations/segmentio/lib/index.js#L290-L291}
+   * Information about the current library.
+   *
+   * **Automatically filled out by the library.**
+   *
+   * This type should probably be "never"
    */
   library?: {
+    /**
+     * @example analytics-node-next/latest
+     */
     name: string
+    /**
+     * @example  "1.43.1"
+     */
     version: string
   }
 
   /**
-   * {@link https://github.com/segmentio/analytics.js-integrations/blob/2d5c637c022d2661c23449aed237d0d546bf062d/integrations/segmentio/lib/index.js#L292-L301}
+   * This is useful in cases where you need to track an event,
+   * but also associate information from a previous identify call.
+   * You should fill this object the same way you would fill traits in an identify call.
    */
-  traits?: {
-    crossDomainId?: string
-  }
+  traits?: CoreAnalyticsTraits
 
   /**
-   * utm params
-   * {@link https://github.com/segmentio/analytics.js-integrations/blob/2d5c637c022d2661c23449aed237d0d546bf062d/integrations/segmentio/lib/index.js#L303-L305}
-   * {@link https://github.com/segmentio/utm-params/blob/master/lib/index.js#L49}
+   * Dictionary of information about the campaign that resulted in the API call, containing name, source, medium, term, content, and any other custom UTM parameter.
    */
   campaign?: {
-    /**
-     * This can also come from the "utm_campaign" param
-     *
-     * {@link https://github.com/segmentio/utm-params/blob/master/lib/index.js#L40}
-     */
     name: string
     term: string
     source: string
@@ -94,21 +154,23 @@ interface CoreAnalyticsContext {
   }
 
   /**
-   *  {@link https://github.com/segmentio/analytics.js-integrations/blob/2d5c637c022d2661c23449aed237d0d546bf062d/integrations/segmentio/lib/index.js#L415}
+   * Dictionary of information about the way the user was referred to the website or app.
    */
   referrer?: {
-    btid?: string
-    urid?: string
+    type?: string
+    name?: string
+    url?: string
+    link?: string
+
+    btid?: string // undocumented?
+    urid?: string // undocumented?
   }
 
-  /**
-   * {@link https://github.com/segmentio/analytics.js-integrations/blob/2d5c637c022d2661c23449aed237d0d546bf062d/integrations/segmentio/lib/index.js#L322}
-   */
   amp?: {
+    // undocumented?
     id: string
   }
 
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
   [key: string]: any
 }
 
@@ -122,10 +184,10 @@ export interface CoreSegmentEvent {
 
   properties?: EventProperties
 
-  traits?: Traits // Traits is only defined in 'identify' and 'group', even if it can be passed in other calls.
+  traits?: CoreAnalyticsTraits // Traits is only defined in 'identify' and 'group', even if it can be passed in other calls.
 
   integrations?: Integrations
-  context?: CoreAnalyticsContext | CoreOptions
+  context?: CoreExtraContext
   options?: CoreOptions
 
   userId?: ID
@@ -141,7 +203,7 @@ export interface CoreSegmentEvent {
 
   _metadata?: SegmentEventMetadata
 
-  timestamp?: Date | string
+  timestamp?: Timestamp
 }
 
 export interface SegmentEventMetadata {
@@ -154,7 +216,7 @@ export interface SegmentEventMetadata {
   bundledIds?: string[]
 }
 
-export type SegmentEventTimestamp = Date | string
+export type Timestamp = Date | string
 
 export interface Plan {
   track?: TrackPlan
@@ -179,34 +241,127 @@ interface PlanEvent {
   }
 }
 
-export interface ReservedTraits {
-  address: Partial<{
-    city: string
-    country: string
-    postalCode: string
-    state: string
-    street: string
-  }>
-  age: number
-  avatar: string
-  birthday: Date
-  company: Partial<{
-    name: string
-    id: string | number
-    industry: string
-    employee_count: number
-  }>
-  plan: string
-  createdAt: Date
-  description: string
-  email: string
-  firstName: string
-  gender: string
-  id: string
-  lastName: string
-  name: string
-  phone: string
-  title: string
-  username: string
-  website: string
+/**
+ * Traits are pieces of information you know about a user.
+ * This interface represents reserved traits that Segment has standardized.
+ * @link https://segment.com/docs/connections/spec/identify/#traits
+ * @link https://segment.com/docs/connections/spec/group/#traits
+ */
+export interface CoreAnalyticsTraits {
+  /**
+   * Unique ID in your database for a user/group.
+   */
+  id?: string
+
+  /**
+   * Industry a user works in, or a group is part of.
+   */
+  industry?: string
+
+  /**
+   * First name of a user.
+   */
+  firstName?: string
+
+  /**
+   * Last name of a user.
+   */
+  lastName?: string
+
+  /**
+   * Full name of a user/group. If you only pass a first and last name Segment automatically fills in the full name for you.
+   */
+  name?: string
+
+  /**
+   * Phone number of a user/group.
+   */
+  phone?: string
+
+  /**
+   * Title of a user, usually related to their position at a specific company.
+   * @example VP of Engineering
+   */
+  title?: string
+
+  /**
+   * User’s username. This should be unique to each user, like the usernames of Twitter or GitHub.
+   */
+  username?: string
+
+  /**
+   * Website of a user/group.
+   */
+  website?: string
+
+  /**
+   * Street address of a user/group.
+   */
+  address?: {
+    city?: string
+    country?: string
+    postalCode?: string
+    state?: string
+    street?: string
+  }
+
+  /**
+   * Age of a user.
+   */
+  age?: number
+
+  /**
+   * URL to an avatar image for the user/group.
+   */
+  avatar?: string
+
+  /**
+   * User's birthday.
+   */
+  birthday?: Timestamp
+
+  /**
+   * User's company.
+   */
+  company?: {
+    name?: string
+    id?: string | number
+    industry?: CoreAnalyticsTraits['industry']
+    employee_count?: CoreAnalyticsTraits['employees']
+    plan?: CoreAnalyticsTraits['plan']
+  }
+
+  /**
+   * Number of employees of a group, typically used for companies.
+   */
+  employees?: number
+
+  /**
+    Plan that a user/group is in.
+
+   * @example enterprise
+   */
+  plan?: string
+
+  /**
+   * 	Date the user/group's account was first created. Segment recommends using ISO-8601 date strings.
+   */
+  createdAt?: Timestamp
+
+  /**
+   * Description of user/group, such as bio.
+   */
+  description?: string
+
+  /**
+   * Email address of a user/group.
+   */
+  email?: string
+
+  /**
+   * @example female
+   */
+  gender?: string
+
+  [customTrait: string]: any
 }
diff --git a/packages/core/src/utils/ts-helpers.ts b/packages/core/src/utils/ts-helpers.ts
new file mode 100644
index 000000000..e13cb8280
--- /dev/null
+++ b/packages/core/src/utils/ts-helpers.ts
@@ -0,0 +1,6 @@
+/**
+ * Remove Index Signature
+ */
+export type RemoveIndexSignature<T> = {
+  [K in keyof T as {} extends Record<K, 1> ? never : K]: T[K]
+}
diff --git a/packages/node/src/app/analytics-node.ts b/packages/node/src/app/analytics-node.ts
index d76efc027..eb9283348 100644
--- a/packages/node/src/app/analytics-node.ts
+++ b/packages/node/src/app/analytics-node.ts
@@ -1,6 +1,5 @@
 import {
   EventProperties,
-  Traits,
   CoreAnalytics,
   CoreContext,
   CorePlugin,
@@ -11,6 +10,8 @@ import {
   PriorityQueue,
   pTimeout,
   Integrations,
+  CoreExtraContext,
+  CoreAnalyticsTraits,
 } from '@segment/analytics-core'
 import { AnalyticsSettings, validateSettings } from './settings'
 import { version } from '../../package.json'
@@ -36,7 +37,17 @@ type IdentityOptions =
  * A dictionary of extra context to attach to the call.
  * Note: context differs from traits because it is not attributes of the user itself.
  */
-type AdditionalContext = Record<string, any>
+export interface ExtraContext extends CoreExtraContext {}
+
+/**
+ * Traits are pieces of information you know about a user that are included in an identify call. These could be demographics like age or gender, account-specific like plan, or even things like whether a user has seen a particular A/B test variation. Up to you!
+ * Segment has reserved some traits that have semantic meanings for users, and we handle them in special ways. For example, Segment always expects email to be a string of the user’s email address.
+ *
+ * We’ll send this on to destinations like Mailchimp that require an email address for their tracking.
+ *
+ * You should only use reserved traits for their intended meaning.
+ */
+export interface Traits extends CoreAnalyticsTraits {}
 
 class NodePriorityQueue extends PriorityQueue<Context> {
   constructor() {
@@ -161,7 +172,7 @@ export class Analytics extends NodeEmitter implements CoreAnalytics {
       userId: string
       /* The previous id that the user was recognized by (this can be either a userId or an anonymousId). */
       previousId: string
-      context?: AdditionalContext
+      context?: ExtraContext
       timestamp?: Timestamp
       integrations?: Integrations
     },
@@ -191,7 +202,7 @@ export class Analytics extends NodeEmitter implements CoreAnalytics {
     }: IdentityOptions & {
       groupId: string
       traits?: Traits
-      context?: AdditionalContext
+      context?: ExtraContext
       timestamp?: Timestamp
       integrations?: Integrations
     },
@@ -221,7 +232,7 @@ export class Analytics extends NodeEmitter implements CoreAnalytics {
       integrations,
     }: IdentityOptions & {
       traits?: Traits
-      context?: AdditionalContext
+      context?: ExtraContext
       integrations?: Integrations
     },
     callback?: Callback
@@ -257,7 +268,7 @@ export class Analytics extends NodeEmitter implements CoreAnalytics {
       /* A dictionary of properties of the page. */
       properties?: EventProperties
       timestamp?: Timestamp
-      context?: AdditionalContext
+      context?: ExtraContext
       integrations?: Integrations
     },
     callback?: Callback
@@ -316,7 +327,7 @@ export class Analytics extends NodeEmitter implements CoreAnalytics {
     }: IdentityOptions & {
       event: string
       properties?: EventProperties
-      context?: AdditionalContext
+      context?: ExtraContext
       timestamp?: Timestamp
       integrations?: Integrations
     },
diff --git a/packages/node/src/index.ts b/packages/node/src/index.ts
index 6cc6f30d4..64abd94f6 100644
--- a/packages/node/src/index.ts
+++ b/packages/node/src/index.ts
@@ -1,4 +1,10 @@
-export { Analytics, Context, Plugin } from './app/analytics-node'
+export {
+  Analytics,
+  Context,
+  Plugin,
+  ExtraContext,
+  Traits,
+} from './app/analytics-node'
 export type { AnalyticsSettings } from './app/settings'
 
 // export Analytics as both a named export and a default export (for backwards-compat. reasons)