MeterCall Offset — dev docs

Embedded renewable energy credit retirement on every API + RPC call. Fractional cents per call, verifiable receipts, enterprise-grade ESG compliance — from the same tollbooth your traffic already passes through.

Overview

Every call your agent, backend, or smart-contract client makes through MeterCall consumes real electricity — server compute, network transit, and (for chain calls) downstream gas. We publish the per-call energy numbers, price them at grid REC cost, mark them up transparently 2×, and retire a proportional renewable energy credit on your behalf. Opt-in. No subscription. One toggle.

Competitors like Watershed, Persefoni, and Sweep help you account for carbon. They can't retire RECs on every API call your software makes. We can — because the calls already pass through us.

Energy model

All figures are published. Sources cited below. Numbers are intentionally conservative (we'd rather over-retire than under).

Sources

• Fly.io 2024 energy transparency report — 0.3–0.5 Wh / request for small compute → we picked 0.4 Wh.
• Cloudflare green compute 2023 figures — 1–2 Wh for cross-datacenter routing → 1.2 Wh for multi-chain router quote.
• Etherscan / L2Beat 2025 tx-energy estimates — bridge calls aggregate a signed tx + downstream RPC + chain gas → 2.5 Wh.
• US EIA 2024 grid average — 0.86 lbs CO₂ / kWh (0.39 kg / kWh).
• NREL Q1 2026 US REC spot — ~$0.125 / kWh-equivalent (national average).

Pricing & markup

We charge exactly 2× the wholesale REC price. Here's the split:

• 1× wholesale — the actual REC we retire on the registry.
• 0.5× verification — registry fees, retirement proof, third-party audit.
• 0.5× MeterCall green fund — grant pool for efficiency R&D on the platform (lower per-call energy, direct wind/solar PPAs, etc). Published quarterly.

Endpoints

curl "https://metercall.ai/v1/offset/estimate?api_calls=1000000&bridge_calls=5000&router_quotes=20000"
# →
{
  "ok": true,
  "total_wh": 418000.0,
  "total_usd": 104.5,
  "breakdown": {
    "api":    { "wh": 400000, "usd": 100.0 },
    "bridge": { "wh":  12500, "usd":   3.125 },
    "router": { "wh":  24000, "usd":   6.0 }
  },
  "rec_units": 0.418,
  "energy_model": { "api_call": 0.4, "bridge": 2.5, "router_quote": 1.2 }
}

curl -X POST https://metercall.ai/v1/offset/purchase \
  -H "content-type: application/json" \
  -d '{"amount_usd": 50, "wallet_or_stripe_ref": "acme-corp"}'
# →
{
  "ok": true,
  "offset_id": "a3c1f9e0b7a4",
  "rec_id": "REC-PATCH-4F91A0C2EE",
  "provider": "Patch.io",
  "registry": "patch.io",
  "wh_offset": 200000,
  "co2_kg_avoided": 78,
  "usd": 50,
  "retired_at": "2026-04-17T18:22:10.000Z",
  "receipt_url": "/v1/offset/receipt/a3c1f9e0b7a4"
}

curl -X POST https://metercall.ai/v1/offset/per-call \
  -H "content-type: application/json" \
  -d '{"call_id":"req_abc","endpoint":"/v1/bridge/swap","auto":true}'

curl -X POST https://metercall.ai/v1/offset/subscribe \
  -H "content-type: application/json" \
  -d '{"wallet_or_user":"0xabc...","auto_offset":true,"daily_cap_usd":5}'

Provider integrations

Round-robin across the public registries and carbon-removal APIs. Each provider flips from stub to live the moment its env var is present. Zero code changes.

BYO REC portfolio

Enterprise customers with an existing REC pool (from Watershed, CIP, etc.) can point MeterCall at it. We'll retire against your portfolio instead of buying spot. Set OFFSET_PORTFOLIO_ID and OFFSET_PORTFOLIO_PROVIDER and the gateway will route retirements to your registry account directly.

Auto-offset subscription

Instead of retiring on every single call (which would add a network hop), subscribe once:

POST /v1/offset/subscribe
{
  "wallet_or_user": "acme-corp",
  "auto_offset": true,
  "daily_cap_usd": 10
}

A server-side bot (internally Bot #26) runs every 60 minutes, sums each subscriber's pending energy, and retires one batch REC up to the daily cap. Receipts are still per-subscriber.

Retirement receipts

Each receipt has:

• offset_id — MeterCall-side ID (12-char sha256 prefix, deterministic).
• rec_id — the provider-side retirement ID. Cross-checkable on their registry.
• provider, registry — which issuer retired the REC.
• wh_offset, kwh_offset, co2_kg_avoided.
• mode — stub (dev) or live (provider env var set).
• retired_at (ISO-8601) and a receipt_url.

On-chain attestation (optional)

For crypto-native teams: every retirement receipt can be anchored on-chain through /v1/bridge/attest, which writes to Arweave or creates an EAS attestation on Base. One call; the attestation transaction hash is appended to the receipt.

POST /v1/bridge/attest
{
  "kind": "rec_retirement",
  "offset_id": "a3c1f9e0b7a4",
  "chain": "base"
}

Enterprise invoicing

Monthly invoice rolls every retirement into one line item: "MeterCall REC retirement — N kWh — $X.XX". Attach ?invoice=2026-04 to /v1/offset/receipts for a filterable feed. Audit-ready CSV export planned for May.

SDK

Drop /sdks/offset.js anywhere — UMD, no deps, browser + Node:

<script src="/sdks/offset.js"></script>
<script>
MeterCallOffset.estimate({ api_calls: 1e6, bridge_calls: 5000, router_quotes: 20000 })
  .then(q => console.log(q.total_usd));
</script>