Getting started

Network status

Fidemark is live on Base Sepolia (chainId 84532). Base mainnet is not yet live, the deploy is held until the public test period closes. Examples below use base-sepolia. See Networks for the full address + schema-UID table.

This guide takes you from install to a verified attestation on Base, in TypeScript, Python, or Go.

1. Install the SDK

TypeScript

npm install @fidemark/sdk ethers

Python

pip install fidemark

Go

go get github.com/fidemark/sdk-go/fidemark

2. Attest a piece of content

TypeScript

import { Fidemark, getNetwork } from "@fidemark/sdk";
import { JsonRpcProvider, Wallet, NonceManager } from "ethers";

const network = getNetwork("base-sepolia"); // or "base" for mainnet
const provider = new JsonRpcProvider(network.rpcUrl);
const signer = new NonceManager(new Wallet(process.env.PRIVATE_KEY!, provider));

const fidemark = new Fidemark({ network, signer });

const { uid, verifyUrl } = await fidemark.attestHuman({
  content: "An essay I wrote myself.",
  contentType: "text/article",
});

console.log(uid);
console.log(verifyUrl);

Python

import os
from fidemark import Fidemark, AttestHumanInput, get_network

network = get_network("base-sepolia")  # or "base"
fidemark = Fidemark(network=network, private_key=os.environ["PRIVATE_KEY"])

result = fidemark.attest_human(
    AttestHumanInput(
        content="An essay I wrote myself.",
        content_type="text/article",
    )
)
print(result.uid)
print(result.verify_url)

Go

package main

import (
    "context"
    "log"
    "os"

    "github.com/fidemark/sdk-go/fidemark"
)

func main() {
    network, err := fidemark.GetNetwork("base-sepolia") // or "base"
    if err != nil { log.Fatal(err) }

    client, err := fidemark.New(fidemark.Config{
        Network:    network,
        PrivateKey: os.Getenv("PRIVATE_KEY"),
    })
    if err != nil { log.Fatal(err) }

    res, err := client.AttestHuman(context.Background(), fidemark.AttestHumanInput{
        Content:     []byte("An essay I wrote myself."),
        ContentType: "text/article",
    })
    if err != nil { log.Fatal(err) }
    log.Println(res.UID)
    log.Println(res.VerifyURL)
}

The SDK hashed your content client-side, encoded the EAS payload, signed the transaction, and broadcast it. The original content never left your machine; only the SHA-256 digest went on chain.

3. Verify it

TypeScript

const att = await fidemark.verify(uid);

Python

att = fidemark.verify(uid)

Go

att, err := client.Verify(context.Background(), uid)

All three return the same shape: type, attester, contentHash, decoded type-specific fields (human, ai, …), and revoked. Or open verifyUrl in any browser, verification is a read-only on-chain query, no wallet required.

4. Attest an AI output

TypeScript

const result = await fidemark.attestAI({
  content: aiResponseText,
  modelId: "claude-sonnet-4-6",
  provider: "anthropic",
  prompt: originalPrompt,
  parameters: { temperature: 0.7 },
});

Python

from fidemark import AttestAIInput

result = fidemark.attest_ai(AttestAIInput(
    content=ai_response_text,
    model_id="claude-sonnet-4-6",
    provider="anthropic",
    prompt=original_prompt,
    parameters={"temperature": 0.7},
))

Go

res, err := client.AttestAI(ctx, fidemark.AttestAIInput{
    Content:    []byte(aiResponseText),
    ModelID:    "claude-sonnet-4-6",
    Provider:   "anthropic",
    Prompt:     []byte(originalPrompt),
    Parameters: `{"temperature":0.7}`,
})

The SDK hashes the prompt to bytes32 so the attestation proves which prompt produced the output without revealing the prompt itself.

What’s next

• Concepts → How it works: what’s actually on chain.
• Concepts → Trust layers: how proofMethod upgrades from a wallet signature to ENS, multi-party, or proof-of-personhood.
• SDK → Installation: full surface parity table across TypeScript, Python, and Go.
• SDK → Configuration: pointing the SDK at Base Sepolia or Base mainnet.
• Embeddable badge: drop a verifier badge into any web page.