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# Notifications
A notification records an event for an agent to act on, such as a failed build, a pull request comment, or a completed background job. Mastra stores it in a durable inbox, separate from the conversation's messages. The event remains available even if the agent is busy when it arrives.
A delivery policy decides whether to send the event immediately, summarize it with other events, or leave it for later. The agent uses the inbox to read, dismiss, or archive records. Delivery can fail, and policies can discard events, so storing a record doesn't guarantee that the agent will act on it. The [Notifications reference](https://mastra.ai/reference/signals/notifications) describes the record lifecycle and policy options.
Use notifications for events that need this inbox and delivery behavior. Use [`sendMessage()`](https://mastra.ai/reference/agents/agent) for user input, a [state signal](https://mastra.ai/docs/signals/state-signals) for changing application context, or a [transient reactive signal](https://mastra.ai/docs/signals/sending-signals) for context needed by one model request. [`sendSignal({ type: 'notification' })`](https://mastra.ai/reference/agents/agent) sends event context without creating an inbox record or providing its retries.
## Quickstart
Call [`agent.sendNotificationSignal()`](https://mastra.ai/reference/agents/agent) to create the record and apply its delivery policy. To let the agent read pending records, add [`createNotificationInboxTool()`](https://mastra.ai/reference/signals/create-notification-inbox-tool) as shown in [Work with the inbox](#work-with-the-inbox).
Records need a storage adapter with the `notifications` domain. This example uses libSQL, subscribes to the thread first, then sends a high-priority CI failure:
```typescript
import { Mastra } from '@mastra/core'
import { Agent } from '@mastra/core/agent'
import { LibSQLStore } from '@mastra/libsql'
import { Memory } from '@mastra/memory'
const storage = new LibSQLStore({
id: 'mastra',
url: 'file:./mastra.db',
})
const ciAgent = new Agent({
id: 'ci-agent',
name: 'CI Agent',
instructions: 'Triage CI failures and explain what broke.',
model: 'openai/gpt-6.1-sol',
memory: new Memory({ storage }),
})
const mastra = new Mastra({
agents: { ciAgent },
storage,
})
const agent = mastra.getAgent('ciAgent')
const thread = {
resourceId: 'user_123',
threadId: 'thread_456',
}
const subscription = await agent.subscribeToThread(thread)
const { record, decision } = await agent.sendNotificationSignal(
{
source: 'github',
kind: 'ci-status',
priority: 'high',
summary: 'CI failed on main: 3 tests failed in the API suite.',
payload: {
repository: 'acme/app',
branch: 'main',
runId: '123456',
},
dedupeKey: 'github:acme/app:main:ci',
},
thread,
)
console.log(record.status, decision.action)
for await (const chunk of subscription.stream) {
console.log(chunk)
if (chunk.type === 'finish') break
}
```
On an idle thread, a high-priority notification delivers immediately and starts a run. On an active thread, Mastra summarizes it first, then delivers the full notification when the thread is idle. The subscription receives both the summary and the full notification as [thread stream](https://mastra.ai/docs/signals/thread-streams) chunks.
## Notification records
When a notification arrives, `sendNotificationSignal()` creates a record or merges it into a matching pending record. It then checks the delivery policy. If delivery is scheduled for later, the dispatcher reads the record when it's due and sends the notification or a summary.
The stored record includes routing, priority, status, delivery attempts, and the original `payload`. The model receives an XML element built from `summary` and attributes. It doesn't receive `payload` automatically.
A record's status can be `pending`, `delivered`, `seen`, `dismissed`, `archived`, `discarded`, or `failed`. A summarized record stays `pending`, because a summary tells the model that records exist without marking them delivered. The reference lists every [record field](https://mastra.ai/reference/signals/notifications) and [status](https://mastra.ai/reference/signals/notifications).
## Create and coalesce records
`sendNotificationSignal()` accepts one notification or an array. Each item is created independently, then storage decides whether it can merge into an existing pending record.
Use `dedupeKey` to identify one event that may arrive more than once. Use `coalesceKey` to group related events into one pending record, a process called coalescing. Both keys use the same matching rules.
Merging only considers records on the same thread, source, kind, agent, and resource that are still pending. The [Notifications reference](https://mastra.ai/reference/signals/notifications) documents the fields that merge and their precedence.
## Storage and dispatcher setup
Notification records require a storage adapter with the `notifications` domain: [libSQL](https://mastra.ai/integrations/databases/libsql), [PostgreSQL](https://mastra.ai/integrations/databases/postgresql), or [MongoDB](https://mastra.ai/integrations/databases/mongodb). Without it, `sendNotificationSignal()` throws instead of silently dropping the record.
Scheduled dispatch is enabled by default and runs through the workflow scheduler. Configure it on the `Mastra` instance:
```typescript
import { Mastra } from '@mastra/core'
export const mastra = new Mastra({
agents: { ciAgent },
storage,
notifications: {
dispatch: {
enabled: true,
cron: '*/1 * * * *',
batchSize: 100,
},
},
})
```
The defaults are `enabled: true`, `cron: '*/1 * * * *'` (once per minute), and `batchSize: 100`. Only apps that defer or summarize a notification create the lazy dispatch schedule and activate the workflow scheduler with it. Set `enabled: false` to opt out.
## Delivery policy
Every record gets a decision when received, and possibly again when dispatched. The built-in policy uses priority and thread state:
| Priority | Idle thread | Active thread |
| -------- | -------------------- | ------------------------------------- |
| `urgent` | Deliver immediately | Deliver immediately |
| `high` | Deliver immediately | Summarize now, then deliver when idle |
| `medium` | Deliver immediately | Batch into a summary |
| `low` | Batch into a summary | Batch into a summary |
Configure a policy on the agent when the defaults don't fit. Source rules run before priority rules, so a noisy source can be summarized while everything else delivers:
```typescript
import { Agent } from '@mastra/core/agent'
import { Memory } from '@mastra/memory'
// storage from the Quickstart
export const ciAgent = new Agent({
id: 'ci-agent',
name: 'CI Agent',
instructions: 'Triage CI failures and explain what broke.',
model: 'openai/gpt-6.1-sol',
memory: new Memory({ storage }),
notifications: {
deliveryPolicy: {
sources: {
github: 'summarize',
},
priorities: {
urgent: 'deliver',
low: 'discard',
},
},
},
})
```
Mastra evaluates the policy in this order:
1. A custom `decide()` function.
2. `sources`, matched against `record.source`.
3. `priorities`, matched against `record.priority`.
4. `default`.
5. The built-in priority policy.
`decide()` runs at receipt and again at delivery for records whose first decision deferred them or scheduled a summary. The stored schedule fixes when and how they deliver. Delivery honors only `streamOptions` and `hold` from the new decision. Keep `decide()` side-effect free.
## Dispatch
The dispatcher reads due records, groups summaries by `agentId`, `resourceId`, and `threadId`, and emits signals through the thread runtime.
| Decision | Result |
| ----------- | ------------------------------------------------- |
| `deliver` | Send the full notification immediately |
| `queue` | Keep the record pending for a later dispatch pass |
| `summarize` | Send a summary now or at `summaryAt` |
| `defer` | Keep the record pending until `deliverAt` |
| `persist` | Store the record without sending a signal |
| `discard` | Mark the record discarded |
A decision with `hold` leaves the record for another process's dispatcher without counting a delivery attempt.
### Summaries
Summaries keep a busy thread from receiving a burst of individual notifications. The model sees a compact digest:
```xml
github: 3, email: 5, slack: 2
```
A full notification delivers the record's summary as its contents:
```xml
CI failed on main: 3 tests failed in the API suite.
```
A summary clears `summaryAt` and sets `summarySignalId`. The records stay `pending` and readable. A full notification sets `deliveredSignalId` and marks the record `delivered`.
Summaries don't mark records delivered. When the agent needs the full content, it reads the records through the inbox; reading can inject the full signal and mark the record `seen`, preventing duplicate delivery later.
### Retries and failures
A failed attempt increments `deliveryAttempts` and records `lastDeliveryAttemptAt` and `lastDeliveryError`. The record stays pending and is due again on the next dispatch pass.
After five failed attempts, the record moves to `failed` and stops being due. The cap is exported as `MAX_NOTIFICATION_DELIVERY_ATTEMPTS`. A `hold` leaves it pending without counting an attempt, so another dispatcher can pick it up.
If a custom policy throws when the notification first arrives, the record stays pending with an immediate `deliverAt` and a failed attempt, so the dispatcher can retry it.
## Work with the inbox
Give the agent the inbox tool so it can inspect records without exposing storage APIs:
```typescript
import { Agent } from '@mastra/core/agent'
import { createNotificationInboxTool } from '@mastra/core/notifications'
const notificationsStorage = await storage.getStore('notifications')
export const ciAgent = new Agent({
// ...id, instructions, model, memory, and notifications from the policy example
tools: {
notificationInbox: createNotificationInboxTool({ storage: notificationsStorage }),
},
})
```
The tool supports `list`, `read`, `search`, `markSeen`, `dismiss`, and `archive`. Listing and searching mark returned unread records `seen`, including `failed` records so the agent learns delivery gave up. `list` defaults to pending, delivered, and failed records. `search` spans all statuses. `read` only acts on pending and delivered records, so it skips `failed` ones. A record `read` can't deliver, because neither the record nor the calling agent supplies a `resourceId`, stays pending.
`read` matters after a summary. It delivers the selected records' full contents as notification signals rather than ordinary tool output. The agent sees the context on the thread even though the call returned a short status message.
## Agent and client surfaces
[`agent.sendNotificationSignal()`](https://mastra.ai/reference/agents/agent) is the canonical way to create durable notification records. It returns the record and the policy decision, and includes `accepted`, `signal`, and `persisted` when a signal was emitted, matching the other signal methods described in [Sending signals](https://mastra.ai/docs/signals/sending-signals).
The JavaScript client SDK can send notification-shaped context through [`client.getAgent().sendSignal()`](https://mastra.ai/reference/client-js/agents). That path bypasses inbox storage, so use it only when the event needs no record, retries, or later reading. Durable records over HTTP go through the AgentController Session notification route, which forwards to `sendNotificationSignal()`. See the [Session reference](https://mastra.ai/reference/agent-controller/session) and [Agent Controller](https://mastra.ai/docs/harness/agent-controller).