ARC-0047: Limit Aleo’s Total Credits Supply to 5 Billion

[raychu86]

---

arc: 0047
title: Limit Aleo’s Total Credits Supply to 5 Billion
authors: @raychu86
discussion: #101
topic: Protocol
status: Accepted
created: 11-26-25

Abstract

This ARC proposes establishing a hard cap of 5,000,000,000 Aleo Credits (ALEO). The cap will be enforced by halting block rewards and proving rewards at a predetermined block height (based on theoretical maximum issuance).

Motivation

Under the current Aleo emission schedule, rewards continue indefinitely and total proving emissions are tied directly to network proving activity. This creates several long-term economic challenges:

• Unbounded inflation in perpetuity.
• Limited predictability around future token supply.
• Uncertainty for participants who rely on fixed-supply or capped-supply economic models.

Establishing a 5 billion ALEO maximum supply addresses these issues by providing:

• Long-term monetary predictability for the ecosystem.
• A clearly bounded total supply, consistent with other fixed-cap digital assets.
• Stable expectations for block producers, provers, developers, and users.

Specification

The Aleo network launched with an initial supply of ~1.5 billion ALEO. All subsequent issuance occurs through block rewards and proving (puzzle) rewards. This ARC does not modify the emission rates of these rewards; instead, it introduces a deterministic point at which both reward streams terminate.

Deterministic Block Height Cap

We define a block height H such that, even if every block from genesis to H paid out the maximum possible proving reward, total issuance could reach, but never exceed 5 billion ALEO.

• H = 263,527,685

At block height H, the following MUST occur:

• Block rewards = 0
• Proving rewards = 0

Because actual proving activity is consistently below the theoretical maximum, realized supply will almost certainly fall below 5B ALEO at the cut-off.

Properties of this approach:

• Simple and deterministic: No runtime supply checks or tracking are required.
• Safe under worst-case assumptions: Even maximum proving throughput cannot push supply above the cap.
• Implementation-light: Only a single network upgrade is required.

Emission Profile

• Block reward emissions are expected to produce ~5% annual inflation on the initial 1.5B supply, i.e., roughly 75M ALEO per year.
• Puzzle reward emissions vary with proving activity. The emission rate decreases over time and becomes flat at year 9 from genesis.

	Block Height	Block Reward (Avg per Block)	Coinbase Reward (Avg per Block)	Actual Total Supply	Theoretical Max Supply (Upper Bound)
Genesis	0	7.1	20.5	1.5B	1.5B
Year 1	10.5M	7.1	19.4	1.816B	1.848B
Year 2	21M	7.1	17.1	-	2.127B
Year 3	31.5M	7.1	14.8	-	2.3820B
Year 4	42M	7.1	12.6	-	2.613B
Year 5	52.6M	7.1	10.3	-	2.820B
Year 6	63.1M	7.1	8.0	-	3.003B
Year 7	73.6M	7.1	5.7	-	3.162B
Year 8	84.1M	7.1	3.42	-	3.297B
Year 9	94.6M	7.1	2.3	-	3.408B
Year 10	105.1M	7.1	2.3	-	3.507B
Year 11	115.6M	7.1	2.3	-	3.606B
Year 12	126.1M	7.1	2.3	-	3.705B
Year 13	136.7M	7.1	2.3	-	3.804B
Year 14	147.2M	7.1	2.3	-	3.903B
Year 15	157.7M	7.1	2.3	-	4.002B
Year 16	168.2M	7.1	2.3	-	4.100B
Year 17	178.7M	7.1	2.3	-	4.200B
Year 18	189.2M	7.1	2.3	-	4.299B
Year 19	199.7M	7.1	2.3	-	4.398B
Year 20	210.2M	7.1	2.3	-	4.497B
Year 21	220.8M	7.1	2.3	-	4.596B
Year 22	231.3M	7.1	2.3	-	4.695B
Year 23	241.8M	7.1	2.3	-	4.794B
Year 24	252.3M	7.1	2.3	-	4.893B
Year 25	262.8M	7.1	2.3	-	4.991B
Year 25 Q4+	263.5M	0	0	-	5B

NOTICE: The upper-bounded total supply shown here is not an emission forecast. It is a theoretical maximum calculated by assuming every block receives the maximum possible mining and block rewards, solely to establish a conservative block-height bound for 5B credits. In practice, actual emissions will be significantly lower than this theoretical cap.

Reference Implementations

An implementation can be viewed here for your review - ProvableHQ/snarkVM#3042

Backward Compatibility

This ARC introduces a new cryptoeconomic mechanism and will require a simple network upgrade. Because this change is planned far in the future, it does not require specifying an explicit consensus-version activation. It is sufficient that node operators upgrade at some point within the ~25-year timeframe. In practice, many other consensus upgrades will occur long before then.

Future Work

Because the changes are not expected to occur until ~Q4 2049, there is flexibility for adjusting the limit height in the future to be more accurate if there are major changes to network assumptions in the future.

[ChinaShenShen]

将 Aleo 的总信用供应量限制在 1 亿