> For the complete documentation index, see [llms.txt](https://zka-protocol.gitbook.io/zka-protocol-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zka-protocol.gitbook.io/zka-protocol-docs/developer/sdk-overview.md).

# SDK Overview

The ZKAP SDK is the primary toolkit for developers integrating anonymous, encrypted, zero-knowledge–validated actions into their applications. It provides high-level functions for identity generation, payload encryption, proof generation, frame construction, and interaction with the ZKAP Validator.

This section gives an overview of the SDK’s architecture, capabilities, and how each component fits into the ZKAP workflow.

***

### 1. What the SDK Does

The ZKAP SDK is responsible for:

* generating ephemeral anonymous identities
* encoding and encrypting payloads
* generating zero-knowledge proofs
* constructing ZKAP Frames
* submitting frames to the validator
* listening to anonymous events
* decrypting the payloads for applications

In short, the SDK acts as the **client-side engine** for ZKAP.

The blockchain only verifies proofs and emits encrypted events;\
the SDK handles everything else.

***

### 2. Key SDK Modules

The SDK is divided into five primary modules:

#### 2.1 Identity Module

Creates ephemeral, unlinkable ZKAP identities.

Functions include:

* `generateIdentity()`
* `deriveNullifier()`
* `createSessionHash()`

#### 2.2 Payload Module

Responsible for:

* serializing payloads
* encrypting using AES-GCM or ChaCha20-Poly1305
* validating structure before proof generation

Functions include:

* `encryptPayload()`
* `decryptPayload()`

#### 2.3 ZK Proof Module

Handles witness generation and proof construction.

Functions include:

* `generateProof()`
* `verifyProof()` (optional for local testing)

Supports:

* Groth16
* Plonk
* Halo2
* STARKs (depending on environment)

#### 2.4 Frame Builder Module

Constructs a valid ZKAP Frame containing:

* zk proof
* commitment root
* encrypted payload
* nullifier
* session hash
* expiry block

Primary function:

* `buildFrame()`

#### 2.5 Validator Interaction Module

Enables submitting frames and listening for events.

Functions:

* `submitFrame()`
* `onAnonymousAction()`
* `decodeEvent()`

***

### 3. End-to-End SDK Workflow

A typical developer workflow using the SDK looks like this:

Step 1 — Generate identity\
Step 2 — Build raw payload\
Step 3 — Encrypt payload\
Step 4 — Generate zero-knowledge proof\
Step 5 — Build ZKAP Frame\
Step 6 — Submit frame to validator\
Step 7 — Listen for AnonymousAction event\
Step 8 — Decrypt and execute logic

The SDK handles each step with simple functions.

Example (conceptual):

const id = generateIdentity();\
const ciphertext = encryptPayload(payload, key);\
const proof = await generateProof(id, ciphertext);\
const frame = buildFrame({ proof, ciphertext, id });\
await submitFrame(frame);

***

### 4. SDK Environment Compatibility

#### 4.1 Browser

• WASM proof generation supported\
• Good for user-facing wallets or interfaces

#### 4.2 Node.js

• Full proof generation\
• Recommended for backend systems or agents

#### 4.3 Serverless

• Frame building works\
• Proof generation may require custom build

#### 4.4 Agent frameworks

• No private keys needed\
• Can generate identities on the fly\
• Execution stays completely private

***

### 5. Supported Cryptographic Backends

The SDK integrates with multiple proof systems:

* SnarkJS (Groth16)
* Plonk
* Halo2 WASM
* Stark-based compilers

Developers can plug in their own backend by implementing the proof interface.

Encryption backends supported:

* AES-GCM
* ChaCha20-Poly1305
* WebCrypto (browser)
* Node crypto module (server)

***

### 6. Error Handling & Safety Guarantees

The SDK provides robust error types for debugging:

* invalid payload format
* proof generation errors
* incorrect encryption key
* replay attempt (duplicate nullifier)
* expiry validation failure
* unsupported proof backend

All unsafe operations include detailed logs and type-checking at compile time (TypeScript).

***

### 7. Who Should Use the SDK?

The SDK is designed for:

* DEX developers
* wallet builders
* agent frameworks
* automation tools
* RFQ systems
* cross-chain routers
* governance systems
* backend services

If your app needs to perform actions privately while ensuring correctness, the SDK is the main integration point.


---

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