canonical: https://jentic.com/apis/amazonaws.com/lambda

# AWS Lambda

Jentic publishes the only available OpenAPI specification for AWS Lambda, keeping it validated and agent-ready. Lambda is the AWS serverless compute service that runs code in response to events without provisioning servers. The 66-endpoint API covers function lifecycle, alias and version management, layers, event source mappings to SQS, Kinesis, and DynamoDB, function URLs, code signing configurations, concurrency controls, and synchronous and asynchronous invocations. It is the foundation of most event-driven AWS architectures and pairs with API Gateway, EventBridge, and S3 for end-to-end serverless applications.

## For AI agents

Deploy, configure, and invoke serverless functions, manage event source mappings, and control concurrency, versions, and aliases on AWS.

## Scope

Does not handle long-running container workloads, persistent VMs, or container image registry operations - use for serverless function lifecycle, invocation, and event source management only.

## Capabilities

- Create and update Lambda functions via /2015-03-31/functions
- Invoke functions synchronously or asynchronously through /2015-03-31/functions/{FunctionName}/invocations
- Publish versions and manage weighted aliases for blue/green deployments
- Wire SQS, Kinesis, DynamoDB Streams, and Kafka triggers via event source mappings
- Configure function URLs for direct HTTPS invocation without API Gateway
- Manage layers for shared code dependencies
- Set reserved and provisioned concurrency to control scaling and cost

## Use cases

### Event-Driven Backend Processing

Process events from S3, SQS, EventBridge, DynamoDB Streams, and Kafka with serverless Lambda functions. The Lambda API creates functions with a chosen runtime, attaches event source mappings that handle batching and retries automatically, and exposes concurrency controls so a runaway producer cannot consume the account quota. Engineers ship business logic as a zip or container image without managing instances.

Example prompt: Create a function 'order-processor' with runtime python3.12 and an SQS event source mapping reading from queue arn:aws:sqs:us-east-1:123:orders

### Blue/Green Deploys with Aliases

Roll out new function code safely by publishing immutable versions and shifting traffic via aliases. The Lambda API supports weighted aliases that split traffic between two versions, enabling canary and linear deployments without external orchestration. Combined with CodeDeploy, alias updates can pause and roll back automatically based on alarms.

Example prompt: Update alias 'live' on function order-processor to send 10 percent of traffic to version 7 and 90 percent to version 6

### Function URLs for Direct HTTPS

Expose a Lambda function over HTTPS without standing up API Gateway. POST /2021-10-31/functions/{FunctionName}/url creates a dedicated URL with optional IAM auth, CORS, and an invoke mode for response streaming. This is the simplest path to a serverless HTTPS endpoint for webhooks, internal tools, or LLM agent backends.

Example prompt: Create a function URL on function 'webhook-receiver' with AWS_IAM auth and CORS allowing origin https://example.com

### AI Agent Serverless Operations

AI agents call Lambda through Jentic to invoke business-logic functions on demand, deploy new functions when teams onboard new workflows, and adjust concurrency in response to alerts. Through Jentic, the agent searches by intent, loads the operation schema, and executes with credentials kept in the vault. SigV4 signing happens inside Jentic so the agent runtime stays simple.

Example prompt: Search Jentic for 'invoke lambda function', load the Invoke schema, and call function 'order-processor' with payload {"orderId": "abc"}

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| POST | /2015-03-31/functions | Create a Lambda function |
| GET | /2015-03-31/functions | List functions |
| POST | /2015-03-31/functions/{FunctionName}/aliases | Create an alias |
| POST | /2015-03-31/event-source-mappings/ | Create an event source mapping |
| POST | /2021-10-31/functions/{FunctionName}/url | Create a function URL |
| POST | /2018-10-31/layers/{LayerName}/versions | Publish a new layer version |

## Key resources

- **Functions** — Create, list, update, invoke, and delete Lambda functions
- **Aliases and Versions** — Publish immutable versions and route traffic with aliases
- **Event Source Mappings** — Connect SQS, Kinesis, DynamoDB, and Kafka triggers
- **Layers** — Manage shared code and dependencies as reusable layers
- **Function URLs** — Expose functions over HTTPS without API Gateway

## Why Jentic

- **Setup:** Wiring the AWS Lambda API by hand means building AWS Signature Version 4 signing, selecting the right regional host from lambda.{region}.amazonaws.com, wiring IAM roles and event source mappings, and handling AWS throttling and retries yourself. Through Jentic you install once, import AWS Lambda from the API Directory, store the AWS access key and secret once, and your agent calls it.
- **Permission scoping:** Lambda puts the function name in the URL path (/2015-03-31/functions/{FunctionName}/...), so a rule can pin your agent to one function: it can invoke and read the configuration of that function and nothing else. You choose the operations it may call, so destructive ones like DeleteFunction or removing an event source mapping are not included unless you add them.
- **Credential handling:** Your AWS access key and secret for Lambda are stored once, encrypted, by your own Jentic One instance and signed with SigV4 at execution time. They never enter the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'invoke a lambda function with a payload' or 'create a lambda event source mapping', and Jentic returns the matching Lambda operation with its input schema so the agent calls the right endpoint without reading the AWS reference.

## Related APIs

- **Amazon API Gateway v2** — HTTP and WebSocket API gateway
- **Amazon EventBridge** — Serverless event bus for AWS and SaaS sources
- **AWS Step Functions** — Serverless workflow orchestration
- **AWS Batch** — Managed batch job execution on AWS compute

## FAQ

### Why is there no official OpenAPI spec for AWS Lambda?

AWS does not publish an OpenAPI specification. Jentic generates and maintains this spec so that AI agents and developers can call AWS Lambda via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

### What authentication does the AWS Lambda API use?

AWS Lambda uses AWS Signature Version 4 (SigV4) HMAC request signing scoped to the Lambda IAM service. Function URLs additionally support AWS_IAM or NONE authorization for direct HTTPS invocations. Through Jentic, AWS credentials live in the encrypted vault and SigV4 signing happens at execution time.

### Can I invoke a Lambda function with the AWS Lambda API?

Yes. Use the Invoke endpoint at POST /2015-03-31/functions/{FunctionName}/invocations with InvocationType set to RequestResponse for synchronous calls, Event for fire-and-forget, or DryRun to validate permissions without executing.

### How do I deploy a new Lambda function through Jentic?

Search Jentic for 'create lambda function', load the schema for POST /2015-03-31/functions, supply the runtime, role ARN, handler, and either a zip code reference or container image URI, then call the same operation with PUT semantics to update code in future. Jentic handles SigV4 signing throughout.

### What are the rate limits for the AWS Lambda API?

Per-region quotas apply, including default concurrent execution limits, function and layer counts, and TPS limits on control plane operations. The Invoke API itself is bounded by reserved or provisioned concurrency on the function. Check the Lambda service quotas in the AWS console for current values.

### Can I expose a Lambda function over HTTPS without API Gateway?

Yes. POST /2021-10-31/functions/{FunctionName}/url creates a dedicated function URL with optional IAM authorization, CORS configuration, and BUFFERED or RESPONSE_STREAM invoke mode for streaming responses.

### Can I run a canary deployment with Lambda aliases?

Yes. Publish a new version with PublishVersion, then update an alias with a routing configuration that points a percentage of traffic to the new version. Combine with CloudWatch alarms and CodeDeploy for automated rollback.

### Can I limit what my agent is allowed to do with the AWS Lambda API?

Yes. Because you run Jentic One yourself, your own rules decide which Lambda operations and which AWS credentials the agent may use. Since Lambda puts the function name in the URL path (/2015-03-31/functions/{FunctionName}/...), a rule can pin the agent to a single function so it only invokes and reads the configuration of that function and nothing else. Destructive operations such as DeleteFunction or removing an event source mapping are excluded unless you explicitly add them to the agent's allowed set.