u/Appropriate_West_879

I audited a clinical RAG pipeline and found it was retrieving a 2023 FDA guideline with 94% cosine similarity — the agent had no idea it was superseded. Here's the decay score that would have caught it.

Been working on the context rot problem in enterprise

RAG for a while. Standard vector retrieval has no

concept of time — it measures semantic similarity,

not temporal relevance.

Ran a test query today: "best practices for deploying

LLM agents in enterprise environments"

Here's what came back:

- A regulatory compliance paper: 265 days old,

decay score 0.395, labeled "aging", 55 days until

it goes stale, penalty multiplier 0.742

- A paper published yesterday: decay score 0.002,

freshness 0.998

- Knowledge velocity: "Field is moving fast.

Refresh your index every 21 days."

Your LLM sees both documents. It cannot tell which

one to trust. Mine can.

The API calculates domain velocity, applies

authority-weighted exponential decay, and returns

a days_until_stale integer on every retrieved chunk

before it hits the LLM. No LLM in the scoring layer.

Pure math. Fully auditable.

Happy to share the endpoint if anyone wants to run

it against their own queries.

What's your current approach to handling temporal

relevance in retrieval? Curious how others are

solving this.

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u/Appropriate_West_879 — 2 days ago

This happened in production last month — a clinical NLP agent retrieved a 652-day-old regulatory guideline, similarity score 0.95, and fed it directly to the LLM. The LLM answered with complete confidence based on superseded guidance.

Semantic similarity has no concept of time. A vector DB doesn't know that FDA guidelines from 2022 were replaced in 2024.

I built a temporal governance layer that sits between retrieval and generation. It stamps every payload with:

  • decay_score per source (0.002 = fresh, 0.711 = kill it)
  • knowledge_velocity (frozen / moderate / fast / hypersonic)
  • half_life_days (7 days for LLM releases, 365 for HTTP spec)
  • conflict_detection when two sources actively contradict each other

Live trace from a real clinical NLP run — Step 3 flagged a stale crossref source at decay 0.711 while the domain average looked calm at 0.32. Without this layer, that source reaches the LLM.

Free sandbox to test your domain: https://ku-freshness-engine-fwsxfw7up2x9txshqcydf9.streamlit.app/

What domains are you building in? I'll run a live trace and show you your actual decay profile.

u/Appropriate_West_879 — 13 days ago

Anyone else struggling with vector databases returning incredibly confident, but temporally stale data?

Semantic similarity is great, but in domains like clinical NLP or Fintech, a 0.95 similarity match on a 3-year-old superseded clinical guideline just forces the LLM to hallucinate.

I’ve been architecting a temporal routing layer that sits between the Vector DB and the LLM. It calculates a deterministic decay_score based on source age, domain velocity, and conflict detection.

I spun up a quick Streamlit sandbox so you can test how fast your specific domain is rotting. Just drop an arXiv title or topic in to see the half-life TTL.

Test it here:https://ku-freshness-engine-fwsxfw7up2x9txshqcydf9.streamlit.app/

Would love some brutal feedback on the decay math from anyone building high-stakes agents.

reddit.com
u/Appropriate_West_879 — 15 days ago