---
slug: threads
title: "Chained saves (threads)"
description: "Chain, don't trim. Split long text and ongoing records with `prev_event_id` so the flow survives."
lang: en
---


# Chained saves (threads)

A memory doesn't always finish in one piece. Sometimes you're splitting a long
document; sometimes you're writing up an investigation that runs for days, or a
procedure with several stages. AiAkiv **weaves these saves into a thread** so you
can follow them in order later.

There's one idea here. **chain it, don't trim it.**

## Why it's needed

Faced with something long, people usually make one of two mistakes.

- **Summarize it in** → the original is gone. You can't recover "what exactly did
  it say" later.
- **Cut it and save only the front** → the rest disappears entirely.

A memory earns its keep by being **recoverable as the original**
([Saving](saving)). So when it's long, you don't shrink it. You **split
and chain it.**

## How they link: `prev_event_id`

When a save finishes, that memory's **`event_id`** comes back. Pass that value as
**`prev_event_id`** on the next piece and the two memories are **linked in
order**.

```
save_memory(summary="Part 1 …", entities=[…], content="…")
  → event_id: evt_a1b2

save_memory(summary="Part 2 …", entities=[…], content="…",
               prev_event_id="evt_a1b2")
  → event_id: evt_c3d4   (linked after evt_a1b2)

save_memory(summary="Part 3 …", entities=[…], content="…",
               prev_event_id="evt_c3d4")
```

You don't have to memorize this. **Every save response carries a
`continuation_hint`** with the exact value to pass on the next call.

**As a person, you just say:**

```
ak continue saving
```

The AI passes the previous save's `event_id` as `prev_event_id` and chains it for
you.

## When to chain

Three cases.

1. **Splitting a long document**: text that won't fit in one save, in order.
2. **An ongoing record**: an investigation spanning days, continuing meeting
   notes, anything where the flow keeps going.
3. **Stage N of a procedure**: work records where the order itself is the
   meaning.

Conversely, **don't chain memories that are independent of each other.** Linking
unrelated things makes search follow the wrong flow later. Only link when "this
continues from that one."

> **It isn't automatic.** The server does not decide continuity by itself.
> Whether a save continues the previous one is **for a person or an AI to judge
> and state.** That's why a single "ak continue saving" matters.

## Size limits: split when you overflow

| Field | Limit | If you exceed it |
|------|------|--------|
| `content` (original) | 50,000 chars | **Split and chain** |
| `summary` | 500 chars | **Compress it** (splitting is not the answer) |

If `content` exceeds the limit the server **refuses** the save, and the error
message explains this splitting method. Don't trim. **split and save again**.

There's one distinction to watch. **A long summary is not a reason to split.** A
summary over 500 characters means the summary is verbose; shorten it. Splitting
and chaining is a device for **when the original is large**, only.

## How it shows up in search

Chained memories appear as one flow in the **link map (hint)** of search results,
and on recall you can follow the chain forward and back
([Searching](searching)). If part 2 of a three-part document matches, the
paths to parts 1 and 3 are shown alongside it.

Splitting the container without losing the flow is the whole point of this
device.

## Cautions

- **The save target must be the same.** If `prev_event_id` isn't a live memory in
  the place you're saving to (the same team and project scope), it is
  **ignored**: the save happens without the link. See [Teams and
  projects](teams-and-projects).
- **Save in order.** Part 1 → 2 → 3, passing the **immediately preceding** save's
  `event_id` each time.
- **Each piece must stand as a real memory.** Fill in a summary, entities, and
  tags for every piece. If only "part 2" matches a search, it has to be readable
  on its own ([Saving](saving)).

## Next

- Saving conventions overall → [Saving](saving)
- Finding chained memories → [Searching](searching)
- The tool rules an AI follows → [For AI agents](for-ai-agents)