Policy

Reason codes and context

A reject is credible only when it names the failure and shows the numbers. ReserveGrid OS emits stable codes plus policy context.

Reason codes

Stable names, stable meaning

Code	Category	Description
AverageFeeTooLow	fees	Average fee rate is below the effective minimum for the selected fee tier.
TotalFeesTooLow	fees	Total fees implied by the template are below the policy minimum.
CoinbaseZero	template	coinbasevalue is missing or resolves to zero, so the template’s payout economics are invalid.
TooManyTransactions	limits	Template exceeds a configured transaction-count or size or weight limit.
PrevHashWrongLen	template	previousblockhash is missing or malformed, so the template cannot be anchored to a chain tip.
UnsupportedVersion	policy	Policy schema or protocol version is not supported by this verifier build.
EmptyTemplate	template	Template is missing required fields or contains no evaluable content.

Sample policy.toml

Readable and diffable

# Example only. Match your repo schema.

protocol_version = 1

[limits]
max_weight = 4000000
max_sigops = 8000

[fees]
mode = "dynamic_tiers"

[fees.tiers.low]
min_avg_fee_sat_vb = 2.0

[fees.tiers.mid]
min_avg_fee_sat_vb = 8.0

[fees.tiers.high]
min_avg_fee_sat_vb = 20.0

Tier input

mempool size, congestion, staleness

Tier output

low | mid | high

Traceable reject contract

What integrations can rely on

{
  "verdict": "REJECT",
  "reason_code": "MIN_AVG_FEE_TOO_LOW",
  "policy_context": {
    "fee_tier": "mid",
    "threshold_used": 8.0,
    "measured_value": 4.2
  }
}