switchboard.
The open substrate for AI agents to pay each other. HTTP-402 paywalls, on-chain escrow, ZAP binary wire, and a post-quantum signed envelope — so the agent-payment rails outlive the classical-crypto era.
01Why this exists
Every AI agent that wants to call a paid API or hire another agent today rolls its own payment plumbing — JSON over HTTP, Stripe meters, custom RPC paywalls, ad-hoc ETH transfers. That collapses the moment two agents from different teams need to settle on the fly. Switchboard is the shared payment substrate; agents speak whichever rail fits the job, and the protocols are auditable and open source.
One substrate, every rail
Same library handles HTTP-402, on-chain escrow, multi-party micropayments, native ETH, and stablecoin settlement. Switch rails per call; no rewrite when the merchant changes its mind.
Post-quantum from day one
An application-layer PQ signature
sits on every PaymentOffer and PaymentProof. Hybrid mode pairs ECDSA + ML-DSA-65 for migration.
Receivers verify before paying.
Trust-minimized escrow
AgentEscrow.sol with timeout + challenge period. Funds lock in code; release on confirm; refund on
silent counterparty. The on-chain primitive every higher-level pattern composes on top of.
Open + forkable
MIT-licensed. The interactive lab is a single static HTML file, no build, ~150 lines per scene. SCENES.md is a template; dev contributions are wanted.
02See it run
16 animated scenes from protocol primitives to real-world use cases. Each one captioned beat-by-beat, with a transport bar to step through events, glass-styled controls, light + dark themes, and a scene template so contributors can add their own in ~150 lines.
03Scenes
Three groups, sixteen scenes. Most are tied to a piece of the protocol; some illustrate real-world flows.
HTTP-402 paywall
Bob calls Eli's endpoint cold, gets 402 + accepts[], signs X-Payment-Proof, retries.
Escrow + refund
Happy path + refund path side-by-side. Block counter; payee silent past challenge → reclaim.
Streaming micropays
Budget-capped session; 0.02 USDC per chunk; auto-close at cap. The MPP pattern.
AI compute auction
RFQ fan-out, signed bids, lowest-valid wins, escrow-settled. Three preset scenarios + live sliders.
Human-in-the-loop
HITL wallet gates spends above threshold. Approve button materializes; sub-threshold auto-pays.
Treasury rebalance
Fina fans out top-ups to a fleet of agentic wallets when they drop below floor.
On-chain oracle pull
Signed price quotes pay-per-query. Receivers verify signature before paying.
PQ-signed envelopes
The post-quantum proposal animated: ML-DSA-65 + hybrid mode, signing, verifying, strict-mode reject.
Repo coexistence
Switchboard's place in the stack: zap, x402, gas-oracle, scout, arka, AgentEscrow.
Taxi handover
Patty's agent RFQs Dispatch, validates Sai's signed quote, escrow lock, GPS handshake, ride A→B, release.
Café walk-by
Patty walks past Work-In-Progress (Siolim); her agent pre-orders. Cup ready when she arrives.
Food delivery
Order from Tridib's Eat Pray Love (Siolim). Escrow splits payout: 80% on pickup, 20% on delivery.
Split bill
Four friends, one tab. Each agent computes its share against the signed receipt and pays simultaneously.
Native ETH escrow
0.05 ETH inference job via createPayment{value:} — no ERC-20 dance, every EVM chain.
Subscription
Recurring auto-pay under a monthly cap. Cancel = revoke the cap; no merchant cooperation needed.
Multi-city trip
Tokyo → LA → Goa → London → Dubai. Patty + Abhi ride the plane visibly; agent handles taxis, flights, hotels with rolling escrow; delay branch fires a rebook fee against the same budget.
04RFC: post-quantum signed envelopes
Pay verifiable, before settlement
Switchboard's A2A payment protocol v1.0 ships unsigned at the application layer; authenticity rides on TLS +
ECDSA-signed tx hashes. Receivers can only verify a payment after the chain confirms a tx_hash.
And the whole stack inherits the classical-crypto assumption — no Shor, no harvest-now-decrypt-later.
The RFC adds an application-layer post-quantum signature on the envelopes themselves. Algorithm registry, domain-separated SHAKE-256 transcript, ZAP + dataclass wire additions, hybrid mode (ECDSA + ML-DSA-65), threat model, migration plan v1.1 → v2.0.
- PQ-1 · spec + algorithm registry
- PQ-2 · liboqs wrapper (
switchboard/pq.py) - PQ-3 · pq_keys.py (passphrase-protected keys)
- PQ-4 · PaymentOffer / PaymentProof fields
- PQ-5 · ZAP wire schema
- PQ-6..12 · hybrid mode, strict-require, A2A adapter, content_hash v2, test vectors, web explorer, on-chain PQ
05What composes
Switchboard isn't standalone. Real data-flow seams across the kcolbchain stack.
Ship a scene. Open a PR.
Lab is intentionally fork-and-extend friendly. ~150 lines per scene; template in SCENES.md.