verified-burst broker

Sell verified inference bursts on Cerebras. An agent hits a hard / irreversible / low-confidence decision and buys more thinking: escalate to fast silicon → best-of-N → verify → pay per burst over x402, charged only if the answer passes. Budget-capped per agent.

BYOK passthrough: the customer's tokens are billed to their own Cerebras key — we never mark up tokens. We charge a small service fee for routing + verification + the burst guarantee. (Legal-clean: selling our application, not reselling their API.)

The wedge — one line for an agent builder

{ "mcpServers": { "verified-burst": {
    "command": "python3", "args": ["/root/inference-burst/mcp_server.py"] } } }

Their agent gains one tool, buy_verified_burst(request, strategy, n, verifier, answer_key), that returns a verified answer + receipt and bills per burst.

Related MCP server: the402-mcp-server

Files

file	role
`provider.py`	BYOK Cerebras call (OpenAI-compatible). Key never stored/logged.
`burst.py`	verified-burst core: best-of-N + self-consistency / deterministic-check / judge verifiers. `passed` gates settlement.
`pricing.py`	service-fee quote (not a token markup).
`x402_gate.py`	x402 challenge + facilitator verify/settle. Settle only on `passed` = pay-only-if-verified. SIM until `X402_FACILITATOR_URL` set.
`broker.py`	orchestration: quote → authorize → burst → settle-IF-verified, + per-agent budget cap.
`server.py`	HTTP surface (`POST /v1/burst`, `GET /v1/quote`, `/healthz`).
`mcp_server.py`	MCP stdio surface — the one-liner.
`measure.py`	the 1-day BYOK measurement harness (offline + live).

Run

# offline measurement / shape
python3 measure.py --offline
# live (needs .env with CEREBRAS_API_KEY)
python3 measure.py
# HTTP broker
PORT=8402 python3 server.py
# MCP server is launched by the MCP client via the config above

Config (.env, gitignored)

CEREBRAS_API_KEY=csk-...        # required (BYOK)
CEREBRAS_MODEL=gpt-oss-120b     # this account: gpt-oss-120b | zai-glm-4.7 (NOT llama)
# x402 (REAL mode — omit for SIM):
X402_FACILITATOR_URL=...        # facilitator that verifies/settles payments
X402_PAY_TO=0x...               # seller wallet that receives USDC
X402_USDC_ASSET=0x...           # USDC contract on the chosen network
X402_NETWORK=base-sepolia

Go-live checklist

x402 creds: facilitator URL + seller wallet (X402_PAY_TO) + USDC asset. Until set, payments run in SIM (flow is real, settlement is stubbed).
Verify pricing: gpt-oss-120b per-token rate (current placeholder is UNVERIFIED) and set FEES in pricing.py to a margin you've checked.
Pick the verifier per use case: self_consistency (cheap, default), judge (adversarial, costs an extra call), or a caller deterministic_check (gold standard).
Budget cap: broker.DEFAULT_BUDGET_USD — wire to the AgentsPrice margin governor for real per-agent caps.
Cerebras gotcha: requests need a browser-ish User-Agent or Cloudflare returns 403 error 1010 (already handled).

Status (2026-06-15)

Core + both surfaces run live against real Cerebras. Verified→charged, failed→not charged, no-payment→402, budget-cap→refused — all confirmed. x402 in SIM pending creds.