---
title: "What is recall in AI agents?"
description: "Recall is the operation that returns stored memory relevant to a query, ranked and dated. How AI agents recall facts with evidence and sources."
canonical: https://past.dev/glossary/recall
last-updated: 2026-09-02
---
# Recall

Source: https://past.dev/glossary/recall

Recall is the operation that returns stored memory relevant to a query, ranked and, in evidence-based systems, dated and attributed to sources. It is the read half of an agent memory system: ingestion writes, recall reads. A recall request carries a natural language query; the response carries the records or facts that answer it, ordered by relevance, with enough context for the agent to use them and cite them.

## How recall works

Recall is the read operation of a memory system. Ingestion writes raw records in; recall brings relevant memory back out. A typical recall pass has four steps:

1. The agent sends a query in natural language describing what it needs.
2. The system gathers candidates by meaning and by exact identifiers. See [hybrid retrieval](/glossary/hybrid-retrieval).
3. Candidates are ranked by relevance to the query, with superseded facts ranked behind current ones.
4. The response is assembled: facts or records, each carrying its date and its source, plus a status value stating what the evidence establishes. See [evidence status](/glossary/evidence-status).

## What a good recall response contains

A ranked list of text chunks is the minimum. An agent acting on the result needs more:

- **Ranking**: the most relevant records first, so a bounded context window gets the best few.
- **Dates**: the event time each record refers to, so the agent can tell current from historical. See [point-in-time recall](/glossary/point-in-time-recall).
- **Sources**: the record each answer came from, so claims can be verified. See [grounding](/glossary/grounding).
- **A status value**: whether the evidence establishes an answer at all. See [abstention](/glossary/abstention).

Recall quality is evaluated by asking questions with known answers against a stored history; the procedure is described in the [benchmark methodology](/benchmarks/methodology).

## Recall in practice

A support agent needs the history behind a ticket and asks what Acme Corp reported in the March 12 outage call. Recall returns the call record dated March 12 ranked first, the follow-up email dated March 14 second, and each carries the ticket and transcript it came from. The agent cites both dates in its reply. In [past.dev](/docs/memory-api/quickstart), recall is `POST /api/v1/recall` with a `query` field, and it returns ranked evidence with dates and sources.

## Related concepts

- **[Recall precision](/glossary/recall-precision)**: how much of what recall returns is actually relevant.
- **[Hybrid retrieval](/glossary/hybrid-retrieval)**: the candidate-gathering strategy behind good recall.
- **[Evidence status](/glossary/evidence-status)**: the label stating what the recalled evidence establishes.
- **[Point-in-time recall](/glossary/point-in-time-recall)**: recalling what was true as of a given date.
- **[Abstention](/glossary/abstention)**: recall declining to answer when evidence is absent.

## Frequently asked questions

### What does recall mean in AI agent memory?

Recall is the operation that fetches stored memory relevant to a query and returns it ranked, so the agent can use it in the current task. In evidence-based systems each result carries its date and source.

### How is recall different from search?

Search finds documents for a person to read. Recall serves an agent mid-task: it returns the specific facts or records the agent needs, ranked, dated, and attributed, so the agent can act on them directly.

### What should a recall response include?

Ranked results, the date each piece of evidence refers to, the source it came from, and a status value saying whether the evidence establishes an answer. Missing dates or sources make results hard to trust.

## Related

- [Recall precision](https://past.dev/glossary/recall-precision)
- [Evidence status](https://past.dev/glossary/evidence-status)
- [Hybrid retrieval](https://past.dev/glossary/hybrid-retrieval)
- [Facts that change over time](https://past.dev/guides/facts-that-change-over-time)
- [Memory API quickstart](https://past.dev/docs/memory-api/quickstart)