quickstart/
quickstart.rs

1//! agent-scroll quickstart — build a 3-turn signed chain, verify, then tamper.
2
3use agent_scroll::{seal_chain, verify, SignOpts};
4use ed25519_dalek::SigningKey;
5use rand::rngs::OsRng;
6use serde_json::{json, Value};
7
8fn main() {
9    // 1. Generate an Ed25519 keypair.
10    let sk = SigningKey::generate(&mut OsRng);
11    let sign = SignOpts {
12        privkey: sk.to_bytes(),
13        pubkey: sk.verifying_key().to_bytes(),
14    };
15
16    // 2. Build three plain turns. timestamp_ns differs so each turn hashes uniquely.
17    let mk = |turn: u64, role: &str, content: &str, ts_offset: u64| {
18        json!({
19            "version": "scroll/0.1",
20            "turn": turn,
21            "role": role,
22            "model": { "vendor": "anthropic", "id": "claude-opus-4-7" },
23            "params": { "temperature": 0, "top_p": 1 },
24            "messages": [{ "role": role, "content": content }],
25            "timestamp_ns": 1_700_000_000_000_000_000u64 + ts_offset,
26        })
27    };
28    let turns: Vec<Value> = vec![
29        mk(0, "user", "What is the capital of France?", 0),
30        mk(1, "assistant", "Paris.", 1),
31        mk(2, "user", "Thanks!", 2),
32    ];
33
34    // 3. Seal + sign as a chain. seal_chain links each turn via prev_hash.
35    let chain = seal_chain(&turns, Some(&sign)).expect("seal_chain");
36    println!("sealed {} turns, all hashes set", chain.len());
37
38    // 4. Verify the clean chain.
39    let clean = verify(&chain, Some(&sign.pubkey));
40    println!("verify clean: ok={}", clean.ok);
41
42    // 5. Tamper: replace one hex char in turn[1]'s hash.
43    let mut tampered = chain.clone();
44    let h = tampered[1]["hash"].as_str().unwrap().to_string();
45    let last = h.chars().last().unwrap();
46    let new_last = if last == '0' { 'f' } else { '0' };
47    let mut new_h: String = h[..h.len() - 1].to_string();
48    new_h.push(new_last);
49    tampered[1]["hash"] = json!(new_h);
50
51    let bad = verify(&tampered, Some(&sign.pubkey));
52    let reason = bad.failures.first().map(|f| f.reason).unwrap_or("none");
53    println!("verify tampered: ok={} reason={}", bad.ok, reason);
54}
quickstart/quickstart.rs

quickstart/
quickstart.rs
