> ## Documentation Index
> Fetch the complete documentation index at: https://docs.neuro-tech.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Keys and signatures

> Understand Agent API key custody and the identifiers needed for signatures

Keys connect authenticated actors to signed identities, agreements, and data. Applications should treat key creation, key identifiers, signing authority, and signature verification as separate concerns.

## How Agent API signing uses keys

The Agent API performs supported cryptographic operations with key material stored encrypted by the Neuron. Your application retains the key identifier, algorithm metadata, and the credentials required to authorize its use.

Keep key passwords distinct from account passwords. A request must bind the acting account, selected key, intended payload, and signing purpose. The Agent API is the same HTTPS interface for ordinary and AI-enabled applications.

## Key workflow

```text theme={null}
Choose a supported algorithm
        ↓
Create a key in the correct account context
        ↓
Persist the caller-supplied key identifier
        ↓
Associate it with the identity or signing workflow
        ↓
Verify the resulting signature or signed object
```

Do not hard-code an algorithm across a long-lived application unless the supported workflow requires it. Query or follow the algorithm guidance for the Neuron version you target.

## Application rules

* Keep passwords, JWTs, key passwords, private keys, and signing secrets out of source control and logs.
* Persist the `id` submitted to `CreateKey`; later operations call the same value `keyId`.
* Make the actor, key, payload, and intended signing purpose explicit.
* Do not claim legal effect or non-repudiation solely because bytes have a valid cryptographic signature; the identity, authorization, contract, policy, and verification context also matter.
* Treat retries carefully. A signing operation may have effects that should not be duplicated unless idempotency is explicitly documented.

## Build with signatures

* [Create cryptographic keys](/neuron-api/guides/creating-cryptographic-keys)
* [Digital signatures](/build/digital-signatures/overview)
* [Cryptography reference](/neuron-api/api-reference/cryptography/overview)