---
title: "What is a memory API?"
description: "A memory API defined: the interface for writing records with timestamps, polling until processing completes, recalling with evidence, and deleting by source."
canonical: https://past.dev/glossary/memory-api
last-updated: 2026-10-17
---
# What is a memory API?

Source: https://past.dev/glossary/memory-api

A memory API is a service interface for storing and recalling an application's knowledge: raw records go in, structured and attributed answers come out. Instead of running its own extraction, entity linking, and temporal logic, an application sends raw records to the API and asks questions later. The interface typically covers four operations: writing records with timestamps, polling until processing completes, recalling with evidence, and deleting by source.

## What the interface covers

A memory API has four concerns, whatever the vendor: getting records in, knowing when they are usable, getting answers out, and removing what should no longer be there.

| Operation | What it does |
| --- | --- |
| Write | Accepts a raw record, its original timestamp, and a stable source id. The timestamp matters because records are often ingested long after the events they describe. |
| Ingestion status | Reports when asynchronous processing has finished for a given write, so callers know when recall reflects it. See [memory consolidation](/glossary/memory-consolidation). |
| Recall | Takes a question and identity and returns ranked documents with dates and source excerpts. |
| Delete | Removes a source and the facts only that source supported, for corrections, retention policies, and erasure requests. |

## Why applications use one

- **One pipeline instead of many.** Coreference, [fact extraction](/glossary/fact-extraction), [entity resolution](/glossary/entity-resolution), and supersession run behind a single write call rather than inside every application.
- **Shared memory.** Several agents and channels write to and recall from the same store, so knowledge from email is available in chat.
- **Governance in one place.** Retention, deletion, and [audit trails](/glossary/audit-trail) attach to the store rather than to each agent.
- **Answers with evidence.** Recall returns dated, source-attributed results rather than bare text, which supports [grounding](/glossary/grounding) and abstention.

## A memory API in practice

A support agent finishes a call with Harborlane on March 12 and writes the transcript to the memory service with the call's timestamp, source id, and author identity. The application polls the ingestion status until processing completes. On October 7, before replying to a Harborlane ticket, the agent recalls the account's invoicing rules and receives ranked documents with the March 12 instruction, occurrence date, and source excerpt.

When Harborlane later requests erasure of the call, deleting that ingestion removes source data and memory supported only by it, and subsequent recalls use what remains. The past.dev public contract exposes ingestion, status, recall and deletion, plus audiences and an identity directory; the [quickstart](/docs/memory-api/quickstart) shows a first write and recall.

## Related concepts

- **[Memory consolidation](/glossary/memory-consolidation)**: the background processing an ingestion status reports on.
- **[Recall](/glossary/recall)**: the read operation, ranked, dated, and attributed.
- **[Evidence status](/glossary/evidence-status)**: the label an application assigns to what recall returns.
- **[Cross-session memory](/glossary/cross-session-memory)**: the capability a memory API exists to provide.
- **Agent memory overview**: [what is agent memory](/what-is-agent-memory) places the API in the wider architecture.

## Frequently asked questions

### What does a memory API do?

It accepts raw records such as emails, transcripts, and notes, structures them into facts about entities over time, and answers later queries with ranked evidence that carries dates and sources.

### How is a memory API different from a vector database?

A vector database is infrastructure: the application embeds, stores, and queries chunks itself. A memory API is a service contract that handles extraction, entity resolution, and temporal tracking behind write, recall, and delete operations.

### How do I add memory to an AI agent?

Send each record the agent should remember to a memory service with its original timestamp, wait for processing to complete, then have the agent call recall with a question before answering. Delete by source when data must be removed.

## Related

- [What is memory consolidation?](https://past.dev/glossary/memory-consolidation)
- [What is recall?](https://past.dev/glossary/recall)
- [What is an evidence status?](https://past.dev/glossary/evidence-status)
- [Memory deletion guide](https://past.dev/guides/gdpr-memory-deletion)
- [Benchmark methodology](https://past.dev/benchmarks/methodology)