# Get Yahoo Mail email threads with Nylas

Source: https://developer.nylas.com/docs/cookbook/email/threads/list-threads-yahoo/

Yahoo Mail doesn't have a native threading API or a concept of conversation grouping at the protocol level. Under the hood, Nylas connects to Yahoo over IMAP and constructs threads by analyzing message headers. The result is a conversation view that works through the same [Threads API](/docs/reference/api/threads/) you'd use for Gmail or Outlook.

This guide covers listing threads from Yahoo accounts, including how Nylas builds threads without native provider support, the 90-day message cache, and what to expect from thread grouping accuracy.

## How do I list Yahoo Mail email threads with the Nylas API?

Send a `GET` request to `/v3/grants/{grant_id}/threads` with your API key. The endpoint returns the most recent threads by default and up to 200 per page, each with a `latest_draft_or_message` object. Yahoo has no native threading, so Nylas builds threads from `In-Reply-To` and `References` headers. See [List threads](#list-threads) for the request and response.

## Why use Nylas for threads instead of IMAP directly?

Yahoo's only developer-facing email interface is raw IMAP, and IMAP has no built-in concept of threads or conversations. To build a conversation view yourself, you'd need to parse `In-Reply-To` and `References` headers from every message, group them by conversation chain, handle subject-line variations, and maintain your own thread index. On top of that, Yahoo requires a signed Commercial Access Agreement before you can get API credentials.

Nylas handles all of this. The Threads API returns pre-grouped conversations with participant lists, read state, and the latest message content. Your code works across Yahoo, Gmail, Outlook, and every other provider without modification.

## Before you begin

You'll need:

- A [Nylas application](/docs/v3/getting-started/) with a valid API key
- A [grant](/docs/v3/auth/) for a Yahoo Mail account
- A Yahoo OAuth connector configured with your Yahoo app credentials (see [Yahoo authentication guide](/docs/provider-guides/yahoo-authentication/))


> **Info:** 
> **New to Nylas?** Start with the [quickstart guide](/docs/v3/getting-started/) to set up your app and connect a test account before continuing here.


### Yahoo OAuth setup

Yahoo requires a few extra steps compared to Google or Microsoft. You'll need to:

1. **Request API access** by submitting a Yahoo Mail API Access form. Yahoo will send you a Commercial Access Agreement to sign. See the [Yahoo authentication guide](/docs/provider-guides/yahoo-authentication/) for the current process.
2. **Create a Yahoo app** by registering your application in the [Yahoo Apps dashboard](https://developer.yahoo.com/apps/) to get a client ID and secret.
3. **Create a Yahoo connector in Nylas** and configure it with your Yahoo client ID and secret.

If you'd rather skip the OAuth setup for testing, you can also authenticate Yahoo accounts using [IMAP with an app password](/docs/provider-guides/yahoo-authentication/#set-up-yahoo-with-imap-authentication). OAuth is the better choice for production apps.

The full setup walkthrough is in the [Yahoo authentication guide](/docs/provider-guides/yahoo-authentication/).

## List threads

Make a [List Threads request](/docs/reference/api/threads/get-threads/) with the grant ID. By default, Nylas returns the most recent threads. These examples limit results to 5:

```bash
curl --compressed --request GET \
  --url "https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/threads?limit=5" \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer <NYLAS_API_KEY>' \
  --header 'Content-Type: application/json'

```

```json
{
  "request_id": "1",
  "data": [
    {
      "starred": false,
      "unread": true,
      "folders": ["CATEGORY_PERSONAL", "INBOX", "UNREAD"],
      "grant_id": "<NYLAS_GRANT_ID>",
      "id": "<THREAD_ID>",
      "object": "thread",
      "latest_draft_or_message": {
        "starred": false,
        "unread": true,
        "folders": ["UNREAD", "CATEGORY_PERSONAL", "INBOX"],
        "grant_id": "<NYLAS_GRANT_ID>",
        "date": 1707836711,
        "from": [
          {
            "name": "Nyla",
            "email": "nyla@example.com"
          }
        ],
        "id": "<MESSAGE_ID>",
        "object": "message",
        "snippet": "Send Email with Nylas APIs",
        "subject": "Learn how to Send Email with Nylas APIs",
        "thread_id": "<THREAD_ID>",
        "to": [
          {
            "email": "nyla@example.com"
          }
        ],
        "created_at": 1707836711,
        "body": "Learn how to send emails using the Nylas APIs!"
      },
      "has_attachments": false,
      "has_drafts": false,
      "earliest_message_date": 1707836711,
      "latest_message_received_date": 1707836711,
      "participants": [
        {
          "email": "nylas@nylas.com"
        }
      ],
      "snippet": "Send Email with Nylas APIs",
      "subject": "Learn how to Send Email with Nylas APIs",
      "message_ids": ["<MESSAGE_ID>"]
    }
  ],
  "next_cursor": "123"
}


```

```js [listThreads-Node.js SDK]

import Nylas from "nylas";

const nylas = new Nylas({
  apiKey: "<NYLAS_API_KEY>",
  apiUri: "<NYLAS_API_URI>",
});

async function fetchRecentThreads() {
  try {
    const identifier = "<NYLAS_GRANT_ID>";
    const threads = await nylas.threads.list({
      identifier: identifier,
      queryParams: {
        limit: 5,
      },
    });

    console.log("Recent Threads:", threads);
  } catch (error) {
    console.error("Error fetching threads:", error);
  }
}

fetchRecentThreads();


```

```python [listThreads-Python SDK]

from nylas import Client

nylas = Client(
    "<NYLAS_API_KEY>",
    "<NYLAS_API_URI>"
)

grant_id = "<NYLAS_GRANT_ID>"

threads = nylas.threads.list(
  grant_id,
  query_params={
    "limit": 5
  }
)

print(threads)

```


```ruby [listThreads-Ruby SDK]
require 'nylas'

nylas = Nylas::Client.new(api_key: '<NYLAS_API_KEY>')
query_params = { limit: 5 }
threads, _ = nylas.threads.list(identifier: '<NYLAS_GRANT_ID>', query_params: query_params)

threads.each {|thread|
  puts "#{thread[:subject]} | Participants: #{thread[:participants].map { |p| p[:email] }.join(', ')}"
}
```

```java [listThreads-Java SDK]
import com.nylas.NylasClient;
import com.nylas.models.*;
import com.nylas.models.Thread;
import java.util.List;

public class ListThreads {
  public static void main(String[] args) throws NylasSdkTimeoutError, NylasApiError {
    NylasClient nylas = new NylasClient.Builder("<NYLAS_API_KEY>").build();
    ListThreadsQueryParams queryParams = new ListThreadsQueryParams.Builder().limit(5).build();
    ListResponse<Thread> threads = nylas.threads().list("<NYLAS_GRANT_ID>", queryParams);

    for(Thread thread : threads.getData()) {
      System.out.println(thread.getSubject());
    }
  }
}
```

```kt [listThreads-Kotlin SDK]
import com.nylas.NylasClient
import com.nylas.models.*

fun main(args: Array<String>) {
    val nylas = NylasClient(apiKey = "<NYLAS_API_KEY>")
    val queryParams = ListThreadsQueryParams(limit = 5)
    val threads = nylas.threads().list("<NYLAS_GRANT_ID>", queryParams).data

    for (thread in threads) {
        println(thread.subject)
    }
}
```


The response includes a `latest_draft_or_message` object with the most recent message's content. The same code works for Google, Microsoft, and IMAP accounts.

## List Yahoo threads from the terminal

Yahoo Mail has no native threading API, so conversations don't exist server-side the way they do on Gmail. The [Nylas CLI](https://cli.nylas.com/docs/commands) reconstructs them from the `References` and `In-Reply-To` headers and shows the result: `nylas email threads list` groups a Yahoo back-and-forth into a single row over IMAP.


The Nylas CLI groups messages into conversations the same way the Threads API does. After `nylas init` and `nylas auth login`, `email threads list` returns the 10 most recent threads by default, each collapsing a full back-and-forth into a single row:

```bash
# List the 10 most recent threads
nylas email threads list

# Only unread threads, filtered by subject
nylas email threads list --unread --subject "invoice"

# Open one thread to see every message in the conversation
nylas email threads show <thread-id>
```

Thread search works differently from message search: it filters by field rather than free text, so you match on `--subject`, `--from`, or `--unread` instead of passing a bare query string:

```bash
# Find threads by subject and sender
nylas email threads search --subject "contract renewal" --from "legal@vendor.com"
```

Both commands accept `--json` for scripting. See the [`email threads list`](https://cli.nylas.com/docs/commands/email-threads-list) and [`email threads search`](https://cli.nylas.com/docs/commands/email-threads-search) command reference for every flag.


Threading quality depends on senders preserving those headers, so a forwarded or header-stripped reply can break out of its thread. The cache keeps about 90 days of Yahoo mail searchable, and [`nylas email threads show`](https://cli.nylas.com/docs/commands/email-threads-show) opens any conversation in full.

## Filter threads

You can narrow results with query parameters. Here's what works with Yahoo accounts:


| Parameter         | What it does                  | Example                       |
| ----------------- | ----------------------------- | ----------------------------- |
| `subject`         | Match on subject line         | `?subject=Weekly standup`     |
| `from`            | Filter by sender              | `?from=alex@example.com`      |
| `to`              | Filter by recipient           | `?to=team@company.com`        |
| `unread`          | Unread only                   | `?unread=true`                |
| `in`              | Filter by folder or label ID  | `?in=INBOX`                   |
| `received_after`  | After a Unix timestamp        | `?received_after=1706000000`  |
| `received_before` | Before a Unix timestamp       | `?received_before=1706100000` |
| `has_attachment`  | Only results with attachments | `?has_attachment=true`        |


Here's how to combine filters. This pulls threads with unread messages from a specific sender:


```bash
curl --request GET \
  --url "https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/threads?from=alex@example.com&unread=true&limit=10" \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer <NYLAS_API_KEY>'
```

```js [filterThreads-Node.js SDK]
const threads = await nylas.threads.list({
  identifier: grantId,
  queryParams: {
    from: "alex@example.com",
    unread: true,
    limit: 10,
  },
});
```

```python [filterThreads-Python SDK]
threads = nylas.threads.list(
    grant_id,
    query_params={
        "from": "alex@example.com",
        "unread": True,
        "limit": 10,
    }
)
```


### Search with `search_query_native`

Yahoo supports the `search_query_native` parameter for IMAP-style search. Unlike Google and Microsoft, Yahoo lets you combine `search_query_native` with any other query parameter, not just `in`, `limit`, and `page_token`.

```bash
curl --request GET \
  --url "https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/threads?search_query_native=subject:invoice&limit=10" \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer <NYLAS_API_KEY>'
```

```js [nativeSearchYahooThreads-Node.js SDK]
const threads = await nylas.threads.list({
  identifier: grantId,
  queryParams: {
    searchQueryNative: "subject:invoice",
    limit: 10,
  },
});
```

```python [nativeSearchYahooThreads-Python SDK]
threads = nylas.threads.list(
    grant_id,
    query_params={
        "search_query_native": "subject:invoice",
        "limit": 10,
    }
)
```

> **Warn:** 
> **Yahoo's IMAP search doesn't support `NOT` syntax.** If you use a negation query, the results may still contain threads you intended to exclude. Filter those out in your application code instead.

See the [search best practices guide](/docs/dev-guide/best-practices/search/) for more on `search_query_native` across providers.

## Things to know about Yahoo threads

Yahoo is IMAP-based with no native threading concept, which means threads behave differently from Google and Microsoft in several ways.

### Threading is constructed, not native

Yahoo doesn't assign a `thread_id` or `ConversationId` to messages. Nylas builds threads by analyzing `In-Reply-To` and `References` headers on each message, combined with subject-line matching. This works well for straightforward reply chains but is less precise than Gmail's native threading.

A few scenarios where you might see differences compared to Gmail:

- **Forwarded messages** may or may not be grouped with the original thread, depending on whether the email client preserved the `References` header
- **Subject-line edits** can cause a message to split into a separate thread
- **Messages without proper headers** (from older or misconfigured email clients) might not group correctly

For most typical email conversations, the threading is accurate. Just be aware that edge cases exist.

### The 90-day message cache affects threads


Nylas maintains a rolling cache of messages from the last 90 days for IMAP-based providers. Threads are built from cached messages, so conversations that span beyond 90 days may appear incomplete. The `message_ids` array only includes messages within the cache window.

To access older messages directly (not as threads), use `query_imap=true` on the Messages API. The Threads API does not support `query_imap`.


### Thread metadata aggregation


Thread-level fields are computed from all cached messages in the conversation:

- `unread` is `true` if any message in the thread is unread
- `starred` is `true` if any message is starred
- `has_attachments` is `true` if any message has attachments
- `participants` is the union of all senders and recipients
- `earliest_message_date` reflects the oldest cached message, not necessarily the start of the conversation


### Sync timing

Yahoo accounts rely on IMAP polling rather than push notifications. New messages typically appear within a few minutes, and threads update accordingly. For faster detection of new messages, use [webhooks](/docs/v3/notifications/) so Nylas notifies your server when changes sync.

### Yahoo's Bulk Mail folder

Yahoo names its spam folder **Bulk Mail**, not "Spam" or "Junk." A thread that includes a flagged message groups under that folder, so it can fall outside an `in=INBOX` filter. Combined with the 90-day cache, spam messages can age out of a thread and leave gaps in the conversation. Call [List Folders](/docs/reference/api/folders/get-folder/) to resolve the Bulk Mail folder ID rather than relying on its name, since the display label varies by account language.

## Paginate through results


The Threads API returns paginated responses. When there are more results, the response includes a `next_cursor` value. Pass it back as `page_token` to get the next page:

```bash
curl --request GET \
  --url "https://api.us.nylas.com/v3/grants/<NYLAS_GRANT_ID>/threads?limit=10&page_token=<NEXT_CURSOR>" \
  --header 'Accept: application/json' \
  --header 'Authorization: Bearer <NYLAS_API_KEY>'
```

```js [paginateThreads-Node.js SDK]
let pageCursor = undefined;

do {
  const result = await nylas.threads.list({
    identifier: grantId,
    queryParams: {
      limit: 10,
      pageToken: pageCursor,
    },
  });

  // Process result.data here

  pageCursor = result.nextCursor;
} while (pageCursor);
```

```python [paginateThreads-Python SDK]
page_cursor = None

while True:
    query = {"limit": 10}
    if page_cursor:
        query["page_token"] = page_cursor

    result = nylas.threads.list(grant_id, query_params=query)

    # Process result.data here

    page_cursor = result.next_cursor
    if not page_cursor:
        break
```

Keep paginating until the response comes back without a `next_cursor`.


## What's next

- [Threads API reference](/docs/reference/api/threads/) for full endpoint documentation and all available parameters
- [Using the Threads API](/docs/v3/email/threads/) for thread concepts and additional operations
- [Messages API reference](/docs/reference/api/messages/) to fetch individual message content from threads
- [List Yahoo messages](/docs/cookbook/email/messages/list-messages-yahoo/) for message-level operations on Yahoo accounts
- [Search best practices](/docs/dev-guide/best-practices/search/) for advanced search with `search_query_native` across providers
- [Webhooks](/docs/v3/notifications/) for real-time notifications instead of polling
- [Yahoo authentication guide](/docs/provider-guides/yahoo-authentication/) for full Yahoo setup including OAuth and IMAP options