---
title: "Episode → Engine Adoption Lag — per-episode variant of Information Lag: how long until each of the five canonical AI engines (ChatGPT, Claude, Gemini, Perplexity, Grok) can name a specific episode the show/creator publishes. Coded text-scan over stored entity_knowledge_snapshots payloads. Zero LLM cost."
method: GET
path: "/entities/{entityId}/episode-adoption-lag"
tags: ["Layer 1 — Profile"]
---

# Episode → Engine Adoption Lag — per-episode variant of Information Lag: how long until each of the five canonical AI engines (ChatGPT, Claude, Gemini, Perplexity, Grok) can name a specific episode the show/creator publishes. Coded text-scan over stored entity_knowledge_snapshots payloads. Zero LLM cost.

`GET /entities/{entityId}/episode-adoption-lag`

## Request

- Base URL: `https://entidex.com/api/v1`
- URL: `https://entidex.com/api/v1/entities/{entityId}/episode-adoption-lag`
- Auth: HTTP bearer

## Path parameters

- `entityId` string, required

## Response `200`

Adoption Lag payload, or { available: false } when the entity has no episodes yet or no snapshot on file has named any episode.

- union
  - EpisodeAdoptionLag
    - `entityId` string, required
    - `available` true, required
    - `computationVersion` string, required
    - `computedAt` string, date-time, required
    - `windowDays` integer, required
    - `episodes` EpisodeAdoptionRead[], required
      - `episodeId` string, required
      - `platform` string, required
      - `platformId` string, required
      - `title` string, nullable
      - `publishedAt` string, date-time, nullable
      - `perEngine` EnginePerEpisodeLag[], required
        - `engine` string, required
        - `maker` string, nullable
        - `makerHref` string, nullable
        - `adoptionLagDays` integer, nullable, required
        - `firstMentionAt` string, date-time, nullable, required
        - `snapshotsInspected` integer, required
      - `meanAdoptionLagDays` number, nullable
      - `enginesAdopted` integer, required
      - `enginesEvaluated` integer, required
    - `perEngine` EngineAdoptionSummary[], required
      - `engine` string, required
      - `maker` string, nullable
      - `makerHref` string, nullable
      - `episodesAdopted` integer, required
      - `episodesEvaluated` integer, required
      - `meanAdoptionLagDays` number, nullable
      - `medianAdoptionLagDays` number, nullable
    - `methodology` string, required
    - `provenance` object, required
      - `issuer` string, required
      - `methodologyUrl` string, uri, required
      - `note` string, required
  - EpisodeAdoptionLagUnavailable
    - `entityId` string, required
    - `available` false, required
    - `reason` 'no_episodes' | 'no_signal_yet' | 'entity_out_of_scope' | 'disabled', required

## Other responses

- `404`: Entity or resource not found.

---

[API](https://skmtc.dev/entidex/apis/entidex-api.md) · [All operations](https://skmtc.dev/entidex/apis/entidex-api/llms.txt) · [OpenAPI document](https://skmtc.dev/entidex/apis/entidex-api/revisions/86b92f21a09a?raw)