Band of Agents Hackathon · Track 3 Regulated · 2026

Apohara
VOUCH.

Vouch for every agent decision.

Cryptographically-verifiable offline receipts for multi-agent AI. Built on Band + AI/ML API + Featherless with a deterministic post-LLM gate. EU AI Act Art. 12 by construction. Verifiable in <30 seconds — no network, no LLM trust.

EU AI Act · Art 12 L2 DORA · Art 16 NIST AI RMF · Manage OWASP Agentic 2026 MIT

9 Agents · Band Court Real WebSocket room on app.band.ai. 9 distinct External Agents + 1 fallback ComplianceVeto.

3 Model Lineages Claude (Anthropic) · Llama/Qwen/DeepSeek (Featherless) · GPT-5.4 (AI/ML API). Anti-consensus-trap.

669KB Verifier Binary Single static vouch-verify. Fits on a USB stick. Runs on a CISO's air-gapped laptop.

<30s Offline Verify No network. No LLM. No platform trust. Ed25519 + BLAKE3 + RFC 3161 chain re-walked locally.

02 / how it works

The 9-agent Band court.

A regulated procurement court runs end-to-end inside a single Band room. Each agent uses a different framework adapter — real cross-framework coordination, not a wrapper. Plus a 10th local fallback ComplianceVeto that fires when the cross-account WebSocket drops.

01 Orchestrator LangGraph GPT-5.4

02 Intake CrewAI Claude Haiku 4.5

03 VendorResearcher LangGraph Llama-3.3-70B-Instruct

04 FinanceRisk Pydantic AI Claude Sonnet 4.5

05 LegalPolicy CrewAI Qwen3-Coder-30B-A3B

06 RedTeam Anthropic SDK Claude Sonnet 4.5

07 ComplianceVeto Band SDK · cross-account Structural · binding veto

08 EvidenceClerk LangGraph DeepSeek-V3-0324

09 ApprovalManager CrewAI Claude Sonnet 4.5

Plus agent 10 — a local fallback ComplianceVeto on the primary account, fires when the cross-account WebSocket drops. Chaos harness verifies 10/10 over 3-kill scenarios.

03 / sponsors

Three production sponsors. Integrated for real.

Every sponsor is integrated for depth that judges score — official SDKs, real WebSockets, 50/50 e2e test gates. Not wrappers.

04 / verify

From LLM verdict to offline pass in <30 seconds.

No network. No LLM. No platform trust. The verifier re-walks the BLAKE3 chain, verifies the Ed25519 signature, checks Art. 12 coverage. Any tamper breaks the chain.

$vouch — terminal output

# 1. Clone the repo
$ git clone https://github.com/SuarezPM/apohara-vouch
$ cd apohara-vouch

# 2. Build the verifier (single static binary, 669KB)
$ cargo build --release -p vouch-verify

# 3. Verify a sample packet, offline, in under 30 seconds
$ ./target/release/vouch-verify fixtures/sample_packet.json

PASS structural PASS hash_format PASS ed25519_signature PASS hash_chain_prev_format PASS eu_ai_act_art12_coverage SKIP rfc3161_timestamp: no DER block in packet (synthetic) PASS tenant_key_match Result: PASS

binary size · 669 KB cold run · ~26.4s on baseline hardware trust model · Ed25519 + BLAKE3 + RFC 3161 scope · vouches the decision, not the LLM

05 / compliance

EU AI Act Art. 12 by construction.

VOUCH is the first multi-agent substrate where the EU AI Act Art. 12 evidence requirements are outputs of the system, not post-hoc additions. The 8 required fields are populated by EvidencePacket::build() and verified by vouch-verify.

Reg 2024/1689

EU AI Act

Art. 12 record-keeping · 8/8 fields populated · verifier requires ≥7/8. Coverage gate is hard, not opt-in.

EU 2022/2554

DORA

Art. 16 ICT incident logging via the same hash chain. BAAAR HALT triggers the 72h DORA Art. 17 reporting clock.

1.0 · G/M/M/M

NIST AI RMF

Per-decision audit trail = the Manage function. Govern / Map / Measure traced in the evidence chain.

2026 · ASI01–ASI10

OWASP Agentic

Prompt injection, sensitive disclosure, tool misuse mitigated inside the BAAAR gate's FindingKind conditions.

# Art. 12 field VOUCH source Example value

1 start_time ISO 8601 UTC at decision window open 2026-06-19T11:43:12Z

2 end_time ISO 8601 UTC at decision window close 2026-06-19T11:43:14Z

3 reference_database Dataset id used for vendor lookup stanford-invoicenet-50

4 input_data Invoice id (decision subject) inv-001

5 decision_id UUID per decision 00000000-0000-0000-0000-000000000001

6 policy_version Agent policy hash apohara-vouch-1

7 hash_chain_prev BLAKE3 root of previous packet 0x0000…0000 (genesis)

8 natural_person_id Required parameter per commit ef9db13 · tenant-scoped operator@stark.example

ApoharaVOUCH.