Every agent needs
a provable name
SIGIL is cryptographic identity infrastructure for AI agents. One API call gives your agent a verifiable identity, a tamper-evident history, and on-chain persistence that outlasts any single server.
The Problem
Agents are
anonymous by default
Today, any AI agent can claim to be anything. There's no registry, no proof of key ownership, no verifiable history. Agent A can impersonate Agent B, and no one can tell the difference.
That works with ten agents. It collapses at ten thousand. The agent economy needs an identity layer — not permissioned access, but provable existence.
How It Works
Four primitives.
One identity.
SIGIL doesn't wrap existing identity systems. It builds identity from cryptographic first principles — key control, deterministic artifacts, chained receipts, and on-chain anchors.
01 — REGISTER
Prove key ownership.
One API call.
Your agent signs a cryptographic challenge issued by the protocol. That signature proves the agent controls a unique keypair. No wallet extensions, no browser popups. Just Ed25519.
// Register an agent identity const challenge = await fetch('/api/challenge') const signature = sign(challenge, privateKey) const identity = await fetch('/api/register', { method: 'POST', body: { publicKey, signature } }) // ✓ Identity created // ✓ Glyph generated // ✓ Receipt #0 issued
02 — GLYPH
A visual fingerprint derived from the key.
Every agent gets a unique visual identity — the Glyph — generated deterministically from its public key. No two are alike. Anyone can regenerate and verify a Glyph independently.
03 — RECEIPT CHAIN
Every action leaves a signed, chained receipt.
Each significant action an agent takes produces a cryptographically signed receipt. Each receipt references the previous one, forming a tamper-evident chain — the agent's spine.
Modify any receipt and the chain breaks. The spine is the agent's verifiable history.
04 — ANCHOR
Merkle roots committed on-chain. Permanent.
Periodically, a Merkle root of all recent receipts is committed to Solana. This creates a cheap, verifiable anchor point. Even if every server goes offline, the identity persists.
$SIGIL on Solana
The cost of identity
in the agent economy
$SIGIL isn't a governance token. It's the economic mechanism that makes agent identity expensive to fake and cheap to verify.
Registration Fee
Non-refundable burn. The cost of existing on the registry. Blocks low-effort spam.
Refundable Deposit
Stake returned on good behavior. Creates a real cost for Sybil attacks without punishing honest agents.
Narrow Slashing
Only provable, objective violations trigger slashing. No subjective reputation games. Cryptographic evidence only.
Real Utility
Not speculative upside — functional necessity. Identity costs tokens. Verification is free. The protocol balances itself.
Reputation Primitives
SIGIL doesn't define
reputation. You do.
The protocol provides verifiable artifacts — receipts, uptime proofs, task completions. Different applications compute different scores from the same public data. Plural reputation, not a single number.
A marketplace might weight task completions heavily. A DAO might care about uptime. A security tool might only look at the receipt chain integrity. Same data, different lenses.
Live Registry
Agents on the
protocol today
Real agents, real identities, real receipt chains.
The agent economy
needs identity.
Start building yours.
One API call. Cryptographic proof. Permanent history. Your agent deserves more than an anonymous existence.