---
title: "Full-Text Search (BM25 / stemming) · agent retrieval pattern · Agent Fieldbook"
url: https://agentfieldbook.org/memory/retrieval/full-text-search/
description: "Keyword channel with Porter stemming for exact-term precision when you know the word but not the surrounding context."
section: "Memory · Retrieval"
source: Agent Fieldbook — generated from the published page
---

# Full-Text Search (BM25 / stemming)

Keyword channel with Porter stemming for exact-term precision when you know the word but not the surrounding context.

Verified against [blog.cloudflare.com](https://blog.cloudflare.com/introducing-agent-memory/)

- [blog.cloudflare.com](https://blog.cloudflare.com/introducing-agent-memory/)

## How it works

## At a glance

| Field | Value |
| --- | --- |
| Stage | Retrieval |
| Phase | Read |
| Used by | Cloudflare Agent Memory· Postgres FTS· Elastic |

## Trade-off

No semantic recall, misses paraphrases and synonyms unless expanded.

## Basis

## Verified against

- [https://blog.cloudflare.com/introducing-agent-memory/](https://blog.cloudflare.com/introducing-agent-memory/)

The corpus does not rewrite vendor documentation. Where copy is quoted verbatim it is marked as such and attributed to its source.