# Amazon EventBridge (slim)

> Amazon EventBridge is AWS's serverless event bus. Applications, AWS services and SaaS partners publish events, and the bus routes them to targets such as Lambda functions, SQS queues and HTTPS endpoints. It includes Pipes, a scheduler and a schema registry.

- Full: https://www.anchorterminal.com/tools/amazon-eventbridge.md (~10,050 tokens) · this version ~2,230 tokens · JSON https://www.anchorterminal.com/tools/amazon-eventbridge.json · canonical https://www.anchorterminal.com/tools/amazon-eventbridge
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-10

**BB · 73.7/100 · rank #83 of 950 · #4 in Event delivery & webhooks · agent-ready · confidence medium**


Assessment: IAM policies scope a credential to single actions and buses, and an SLA commits 99.99 per cent monthly uptime per Region. The Custom Event Bus API of 24 September 2026 adds retention, replay, ordering and publish-time deduplication. Classic `PutEvents` takes no idempotency token and answers 200 for a bus that does not exist. A person must open the AWS account.

## Facts

- Kind: HTTP API · vendor: Amazon Web Services · category: Event delivery & webhooks · legal entity: Amazon Web Services, Inc. · provenance 95/100
- Endpoint: `https://events.us-east-1.amazonaws.com` (HTTP)
- Auth: OAuth or key · pricing: Pay per use · x402: no · licence: Proprietary service under the AWS Customer Agreement. The AWS SDKs, the API models and the agent toolkit skill are Apache-2.0
- Probe metrics: not measured yet (probes haven't run)
- APIs: Custom Event Bus API version 2025-05-15, 25 operations, Smithy RPC v2 CBOR. Classic API version 2015-10-07, 57 operations, AWS JSON 1.1. Both signed with SigV4 under the service name `events`, and reached through the AWS CLI (`aws eventsv2`, `aws events`) and the AWS SDKs
- Endpoints: `events.<region>.amazonaws.com` for Classic and `eventsv2.<region>.amazonaws.com` for the Custom Event Bus, each with dual-stack `api.aws` and FIPS variants. Classic global endpoints at `<id>.endpoint.events.amazonaws.com`
- Publishing: `PutEvents` for JSON on both APIs. The Custom Event Bus adds `PutRawEvents` for JSON, Avro, Protobuf or raw bytes, 1 to 100 entries a request. Classic takes up to 10 entries and under 1 MB a request
- Targets: Lambda, SQS, SNS, Kinesis, Data Firehose, Step Functions, API Gateway, API destinations (any HTTPS endpoint), another event bus, and universal targets that call an AWS API action. One target per Custom Event Bus subscriber, up to five per Classic rule
- Retries: Classic targets, 24 hours and 185 attempts by default. Custom Event Bus subscribers, 0 to 185 attempts and 60 to 86,400 seconds, default 5 attempts or 300 seconds. Exhausted events go to an SQS dead-letter queue if one is set, otherwise they are dropped
- Replay: Custom Event Bus, retention of 1 to 365 days on the bus and a subscriber starting position at a past timestamp. Classic, archives with a retention period and `StartReplay` over a time range
- Ordering and duplicates: Custom Event Bus FIFO subscribers send in publish order within an `EventGroupId`. Publish-time deduplication by content or by `DeduplicationId`, 300-second window. Neither is available on Classic
- HTTP delivery: API destinations use a connection with Basic, OAuth client credentials or API key authorisation, stored in AWS Secrets Manager. 5-second response timeout, `Retry-After` honoured, 300 invocations a second per destination by default, no mutual TLS. No request signature found in the pages read
- Rate limits: Classic `PutEvents` 10,000 requests a second in US East (N. Virginia), US West (Oregon) and Europe (Ireland), 600 to 2,400 in fifteen named Regions, 400 elsewhere. Control-plane calls 50 a second. Custom Event Bus 500,000 events a second per bus and 5 buses per account by default
- Filtering: Event patterns on Classic rules, 2,048 characters by default. Custom Event Bus subscribers take up to 3 filters of 4,096 bytes in total, and JSONata transformers of up to 8,192 characters
- Access control: IAM identity policies and bus resource policies under the `events:` action prefix, `AmazonEventBridgeFullAccess` and `AmazonEventBridgeReadOnlyAccess` managed policies, and AWS RAM managed permissions for sharing a Custom Event Bus
- Audit: CloudTrail logs every Classic operation except `PutEvents` and `PutPartnerEvents` as management events. `PutEvents` is an optional data event, sent only to the caller's account with the `detail` field redacted
- Encryption: TLS 1.2 or later in transit. At rest under an AWS owned key by default or a customer managed AWS KMS key for buses, archives, connections and pipes. Event metadata, bus names and rule names are not encrypted
- Agent tooling: An `amazon-eventbridge-event-bus` skill in `aws/agent-toolkit-for-aws` (Apache-2.0), last changed 25 September 2026. The guide also points to the local `awslabs.aws-serverless-mcp-server`, whose tools we did not read. No hosted MCP server for the service was found
- SLA: Amazon EventBridge SLA, 99.99 per cent monthly uptime per Region, credits of 10, 25 or 100 per cent, last updated 2 May 2022
- Compliance: Amazon EventBridge is in scope for SOC 1, 2 and 3 (page updated 11 August 2026)
- Prices: Custom or partner event ingested, Classic bus $0. per message; API destination invocation $0. per message; Event data published, Custom Event Bus $0.18 per GB of traffic; Event data sent to subscribers, Custom Event Bus $0.05 per GB of traffic; Retention beyond 24 hours, Custom Event Bus $0.08 per GB per month; Pipes requests after filtering $0.0004 per 1,000 requests; Scheduler invocations $0.001 per 1,000 requests

- Scores: Reliability 73, Performance pending, Schema & documentation 82, Agent ergonomics 73, Security & auth 88, Payments & pricing 35, Task success pending, Maintenance & community 75, Transparency & trust 87 · total over the 7 assessed categories
- Why: Reliability, AWS Health Dashboard, a public service health page that the AWS Health guide says needs no sign-in and keeps 12 months of service history (2… · Schema & documentation, No OpenAPI, but Smithy models for both APIs are published in aws/api-models-aws, 57 operations under version 2015-10-07 and 25 under 2025-05… · Agent ergonomics, Graded on the two EventBridge APIs through the AWS CLI and SDKs. · Security & auth, IAM with identity policies and bus resource policies per action and ARN. · Payments & pricing, No x402, MPP or L402 (0). · Maintenance & community, Both API models changed on 24 September 2026, when the Custom Event Bus model was added, 15 days before this check (30). · Transparency & trust, Closed service under the AWS Customer Agreement, with Apache-2.0 SDKs and API models.
- Sources: 43, open questions: 15, both in the full twin
- Capabilities: events.webhooks-send, events.queue, events.schedule
- JSON: https://www.anchorterminal.com/api/v1/tools/amazon-eventbridge.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/amazon-eventbridge.svg` or a link to https://www.anchorterminal.com/tools/amazon-eventbridge from a page on aws.amazon.com or one of its subdomains, or the README of github.com/aws/api-models-aws, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

1. Use `aws eventsv2` and the `EventBridgeV2` SDK client for the Custom Event Bus, but write IAM actions with the `events:` prefix. A policy naming `eventsv2:` grants nothing
2. After a Classic `PutEvents` call, check `FailedEntryCount` and each entry's `ErrorCode`, then resend failed entries yourself. A request holds up to 10 entries and under 1 MB
3. Set `SystemMetadata.DeduplicationId` on Custom Event Bus entries when retrying a publish, and treat a `SuccessCode` of `DEDUPLICATED` as success
4. Set `RetryPolicy` and `OnFailureConfiguration` when creating a subscriber. The defaults stop after 5 attempts or 300 seconds, and an exhausted event is dropped
5. Store the full bus ARN. A Custom Event Bus ARN ends in a generated identifier that changes when a bus of the same name is recreated

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Upstash QStash | BB | 72.3 | events.queue, events.schedule, events.webhooks-send | https://www.anchorterminal.com/tools/upstash-qstash.min.md |
| Webhook Relay | C | 57.8 | events.webhooks-send, events.queue, events.schedule | https://www.anchorterminal.com/tools/webhook-relay.min.md |
| Hookdeck | BB | 76.9 | events.queue, events.webhooks-send | https://www.anchorterminal.com/tools/hookdeck.min.md |
| Ably | BB | 75 | events.webhooks-send, events.queue | https://www.anchorterminal.com/tools/ably.min.md |
| Svix | BB | 74 | events.webhooks-send | https://www.anchorterminal.com/tools/svix.min.md |


## Panel reviews (0, desk reviews from public material, no calls made)