Blob

export type BrandedBlob = Uint8Array & { readonly __blob: unique symbol };

// KZG commitment (48 bytes)
export type Commitment = Uint8Array & { readonly __commitment: unique symbol };

// KZG proof (48 bytes)
export type Proof = Uint8Array & { readonly __proof: unique symbol };

// Versioned hash (32 bytes) - commitment hash with version prefix
export type VersionedHash = Uint8Array & { readonly __versionedHash: unique symbol };

Blob.SIZE                      // 131072 bytes (128 KB)
Blob.FIELD_ELEMENTS_PER_BLOB   // 4096 field elements
Blob.BYTES_PER_FIELD_ELEMENT   // 32 bytes per element
Blob.MAX_PER_TRANSACTION       // 6 blobs maximum
Blob.COMMITMENT_VERSION_KZG    // 0x01 version byte
Blob.GAS_PER_BLOB             // 131072 (2^17)
Blob.TARGET_GAS_PER_BLOCK     // 393216 (3 blobs)

import { Blob } from 'tevm';

// Small data - single blob
const data = new TextEncoder().encode("Rollup batch #1234");
const blob = Blob.fromData(data);

console.log(`Data size: ${data.length} bytes`);
console.log(`Blob size: ${blob.length} bytes`); // Always 131,072

// Extract original data
const decoded = Blob.toData(blob);
console.log(new TextDecoder().decode(decoded)); // "Rollup batch #1234"

import { Blob } from 'tevm';

// Large data spanning multiple blobs
const largeData = new Uint8Array(300_000); // 300 KB

// Estimate blobs needed
const blobCount = Blob.estimateBlobCount(largeData);
console.log(`Requires ${blobCount} blobs`); // 3 blobs

// Split into blobs
const blobs = Blob.splitData(largeData);
console.log(`Created ${blobs.length} blobs`);

// Later: join data back
const reconstructed = Blob.joinData(blobs);
console.log(`Reconstructed ${reconstructed.length} bytes`);

import { Kzg, Blob } from 'tevm';

// Create blob and get versioned hash
const blob = Blob.fromData(data);
const commitment = Kzg.Commitment(blob);
const versionedHash = Blob.toVersionedHash(commitment);

// Use in EIP-4844 transaction
const tx = {
  type: '0x03', // EIP-4844 type
  blobVersionedHashes: [versionedHash],
  maxFeePerBlobGas: 1000000n,
  // ... other fields
};

// Validate versioned hash
console.log(Blob.isValidVersion(versionedHash)); // true
console.log(Blob.VersionedHash.getVersion(versionedHash)); // 1

import { Blob } from 'tevm';

// Calculate gas cost for blob transaction
const blobBaseFee = 50000000n; // 50 gwei (example)
const blobCount = 2;

const blobGas = Blob.calculateGas(blobCount, blobBaseFee);
console.log(`Blob gas cost: ${blobGas} wei`);

// Compare with calldata cost
const calldataBytes = 131072 * 2; // 2 blobs worth
const calldataGas = calldataBytes * 16n; // 16 gas per byte
console.log(`Calldata gas cost: ${calldataGas} wei`);
console.log(`Savings: ${((1 - Number(blobGas) / Number(calldataGas)) * 100).toFixed(1)}%`);

import { Kzg } from 'tevm';

// Multiple blobs with commitments and proofs
const blobs = [blob1, blob2, blob3];
const commitments = blobs.map(b => Kzg.Commitment(b));
const proofs = blobs.map(b => Kzg.Proof(b));

// Verify all at once (more efficient)
const allValid = Kzg.verifyBatch(blobs, commitments, proofs);

if (!allValid) {
  // Fall back to individual verification to find invalid blob
  for (let i = 0; i < blobs.length; i++) {
    const valid = Kzg.verify(blobs[i], commitments[i], proofs[i]);
    if (!valid) {
      console.error(`Blob ${i} failed verification`);
    }
  }
}

// Import specific functions (tree-shakeable)
import { fromData, toData, estimateBlobCount } from 'tevm/BrandedBlob';

const blob = fromData(data);
const decoded = toData(blob);
const count = estimateBlobCount(largeData);

// Only these 3 functions included in bundle