feat: implement dynamic fee tier system for streaming payments (#512) - #557
feat: implement dynamic fee tier system for streaming payments (#512)#557Danielobito009 wants to merge 2 commits into
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…ble-Protocol#512) - Add FeeTier struct for configurable tier-based fee structure - Implement per-donor cumulative volume tracking (all-time) - Add tier-based fee calculation that reduces fees for high-volume donors - Add admin-only set_fee_tiers() function with monotonic fee validation - Add get_fee_tiers() and get_donor_cumulative_volume() query functions - Extend Error enum with InvalidTierConfiguration and TierFeeNotMonotonic - Update initialize() to set default 3-tier structure (5%, 2.5%, 1%) - Update create_stream() to track cumulative volume per donor - Update withdraw() to apply tier-based fees - Add comprehensive test coverage (19 tests) - Include complete documentation on volume tracking semantics and gaming resistance
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Important
This repository does not receive automatic reviews because it has fewer than 10 stars. ⚙️ Run configurationConfiguration used: defaults Review profile: CHILL Plan: Pro Plus Run ID: 📝 WalkthroughWalkthroughRemoved ChangesPayment stream fee tiers
Estimated code review effort: 4 (Complex) | ~45 minutes Sequence Diagram(s)sequenceDiagram
participant Donor
participant PaymentStreamContract
participant TokenContract
participant FeeCollector
Donor->>PaymentStreamContract: create_stream(total_amount)
PaymentStreamContract->>PaymentStreamContract: update donor_volume
Donor->>PaymentStreamContract: withdraw(amount)
PaymentStreamContract->>PaymentStreamContract: select fee tier and calculate protocol fee
PaymentStreamContract->>TokenContract: transfer net withdrawal
PaymentStreamContract->>FeeCollector: transfer protocol fee
Possibly related issues
🚥 Pre-merge checks | ✅ 4 | ❌ 1❌ Failed checks (1 warning)
✅ Passed checks (4 passed)
✨ Finishing Touches🧪 Generate unit tests (beta)
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Actionable comments posted: 5
🧹 Nitpick comments (2)
contracts/payment-stream/src/test.rs (1)
423-429: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick winAssert the specific error code instead of any panic.
Both tests would pass if
set_fee_tierspanicked for an unrelated reason (e.g.InvalidTierConfigurationfiring in the monotonicity test). The generated client exposestry_set_fee_tiers, which lets you pin the variant.♻️ Example
- let result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| { - client.set_fee_tiers(&invalid_tiers); - })); - - // Should fail with TierFeeNotMonotonic - assert!(result.is_err()); + assert_eq!( + client.try_set_fee_tiers(&invalid_tiers), + Err(Ok(Error::TierFeeNotMonotonic)) + );Also applies to: 449-455
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the rest with a brief reason, keep changes minimal, and validate. In `@contracts/payment-stream/src/test.rs` around lines 423 - 429, Update both fee-tier validation tests around set_fee_tiers to call the generated client’s try_set_fee_tiers and assert the returned error is specifically TierFeeNotMonotonic, rather than only checking that a panic occurred. Preserve each test’s invalid tier setup and ensure unrelated error variants do not satisfy the assertions.contracts/payment-stream/src/lib.rs (1)
514-539: 📐 Maintainability & Code Quality | 🔵 Trivial | ⚡ Quick winExtract the duplicated bps fee formula.
The overflow-avoiding formula is repeated verbatim at Line 520 and Line 538; a small helper keeps the two paths from drifting.
♻️ Proposed refactor
+ /// Apply a basis-point rate to `amount` without intermediate overflow. + fn apply_bps(amount: i128, rate: i128) -> i128 { + ((amount / 10000) * rate + ((amount % 10000) * rate) / 10000).max(0) + }- let rate = fee_rate as i128; - return (amount / 10000) * rate + ((amount % 10000) * rate) / 10000; + return Self::apply_bps(amount, fee_rate as i128);- let rate = applicable_fee_rate as i128; - let fee = (amount / 10000) * rate + ((amount % 10000) * rate) / 10000; - fee.max(0) + Self::apply_bps(amount, applicable_fee_rate as i128)🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the rest with a brief reason, keep changes minimal, and validate. In `@contracts/payment-stream/src/lib.rs` around lines 514 - 539, Extract the repeated basis-points fee calculation from the tier fallback and applicable-tier paths into a small helper near the surrounding fee logic. Update both return sites to call this helper with amount and rate, preserving the existing overflow-avoiding arithmetic and zero-rate behavior.
🤖 Prompt for all review comments with AI agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
Inline comments:
In `@contracts/payment-stream/src/lib.rs`:
- Around line 254-261: Update the donor volume accounting in create_stream to
credit only the escrowed initial_amount, not total_amount, and ensure
initial_amount is actually transferred before applying this credit. Add matching
cumulative volume updates in deposit for each additional funded amount, while
preserving the existing overflow handling and donor_volume storage behavior.
In `@contracts/payment-stream/src/test.rs`:
- Around line 649-658: Update the withdrawal balance assertions in the affected
test and test_withdraw to reflect the default 500 bps protocol fee: expect 950
instead of 1000 for a 1000 withdrawal, and 285 instead of 300 for the existing
300 assertion. Leave the withdrawal behavior and other assertions unchanged.
- Around line 562-581: The large-amount test exposes unchecked arithmetic in
withdrawable_amount and protocol_metrics.total_tokens_streamed. Update the
vesting calculation to use checked multiplication with a safe mul-div fallback
before dividing by duration, and use checked addition for cumulative streamed
tokens; preserve correct withdrawal behavior for large values without overflow.
- Around line 792-812: Update the final balance assertion in the cancel-stream
test around client.cancel_stream and token_client.balance so it expects the
sender’s full 1000-token balance after the 500-token escrow is refunded; keep
the existing refund comment and stream status assertion unchanged.
- Around line 386-400: Update the authorization assertion around set_fee_tiers
to verify the specific Error::Unauthorized result rather than only checking for
a panic. Prefer the generated try_set_fee_tiers client method and assert its
returned error, or explicitly mock the admin authorization required by
admin.require_auth() while preserving the existing non-admin rejection scenario.
---
Nitpick comments:
In `@contracts/payment-stream/src/lib.rs`:
- Around line 514-539: Extract the repeated basis-points fee calculation from
the tier fallback and applicable-tier paths into a small helper near the
surrounding fee logic. Update both return sites to call this helper with amount
and rate, preserving the existing overflow-avoiding arithmetic and zero-rate
behavior.
In `@contracts/payment-stream/src/test.rs`:
- Around line 423-429: Update both fee-tier validation tests around
set_fee_tiers to call the generated client’s try_set_fee_tiers and assert the
returned error is specifically TierFeeNotMonotonic, rather than only checking
that a panic occurred. Preserve each test’s invalid tier setup and ensure
unrelated error variants do not satisfy the assertions.
🪄 Autofix (Beta)
Fix all unresolved CodeRabbit comments on this PR:
- Push a commit to this branch (recommended)
- Create a new PR with the fixes
ℹ️ Review info
⚙️ Run configuration
Configuration used: defaults
Review profile: CHILL
Plan: Pro Plus
Run ID: 1bf3cedb-c43e-4b85-a3be-7d78aafabfb5
📒 Files selected for processing (3)
IMPLEMENTATION_SUMMARY.mdcontracts/payment-stream/src/lib.rscontracts/payment-stream/src/test.rs
💤 Files with no reviewable changes (1)
- IMPLEMENTATION_SUMMARY.md
| // Update donor cumulative volume for fee tier calculation | ||
| let donor_volume_key = (Symbol::new(&env, "donor_volume"), sender.clone()); | ||
| let current_volume: i128 = env.storage().persistent().get(&donor_volume_key).unwrap_or(0); | ||
| let new_volume = current_volume.checked_add(total_amount) | ||
| .unwrap_or_else(|| panic_with_error!(&env, Error::ArithmeticOverflow)); | ||
| env.storage().persistent().set(&donor_volume_key, &new_volume); | ||
| env.storage().persistent().extend_ttl(&donor_volume_key, LEDGER_THRESHOLD, LEDGER_BUMP); | ||
|
|
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🔒 Security & Privacy | 🟠 Major | 🏗️ Heavy lift
Volume is credited from total_amount, which is not actually escrowed — donors can self-promote to the lowest fee tier for free.
create_stream accepts initial_amount = 0, so a donor can create a stream with total_amount = 500_000 (no tokens transferred at line 280-283), instantly reach the 100 bps tier, and never fund it. Since volume never decreases, cancelling costs nothing. This directly contradicts the anti-gaming claim documented at lines 480-484.
Consider crediting volume from escrowed funds instead (i.e. accumulate initial_amount here and add to volume on each deposit), so a tier reflects capital actually committed.
🛡️ Sketch: credit only escrowed amount
- let new_volume = current_volume.checked_add(total_amount)
+ let new_volume = current_volume.checked_add(initial_amount)
.unwrap_or_else(|| panic_with_error!(&env, Error::ArithmeticOverflow));Then mirror the same accumulation inside deposit when additional funds arrive.
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
In `@contracts/payment-stream/src/lib.rs` around lines 254 - 261, Update the donor
volume accounting in create_stream to credit only the escrowed initial_amount,
not total_amount, and ensure initial_amount is actually transferred before
applying this credit. Add matching cumulative volume updates in deposit for each
additional funded amount, while preserving the existing overflow handling and
donor_volume storage behavior.
| let result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| { | ||
| env.mock_auth(&[( | ||
| &non_admin, | ||
| MockAuthInvoke { | ||
| contract: &contract_id, | ||
| fn_name: &Symbol::new(&env, "set_fee_tiers"), | ||
| args: (&new_tiers,).into_val(&env), | ||
| invoke_contract: true, | ||
| }, | ||
| )]); | ||
| client.set_fee_tiers(&new_tiers); | ||
| })); | ||
|
|
||
| // We expect this to fail with Unauthorized | ||
| assert!(result.is_err()); |
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📐 Maintainability & Code Quality | 🟡 Minor | ⚡ Quick win
🧩 Analysis chain
🌐 Web query:
soroban-sdk Env mock_auth after mock_all_auths override behavior test authorization
💡 Result:
In the Soroban SDK, authorization mocking functions define how the environment handles Address::require_auth and Address::require_auth_for_args calls during testing [1][2]. Override Behavior: Authorization mocking and setting methods are generally mutually exclusive in a given test environment context [1]. If mocking is enabled, calling set_auths—which requires valid cryptographic signatures—will disable any previously enabled mocking [1]. Conversely, using mock_all_auths or mock_auths overrides or replaces the current authorization state to allow these calls to succeed without valid signatures [1][2]. Key Mocking Functions: 1. mock_all_auths: Causes all calls to require_auth or require_auth_for_args to succeed automatically, regardless of the invocation tree [1][3]. This is convenient but can obscure missing authorization checks [1][4]. 2. mock_all_auths_allowing_non_root_auth: A variant of mock_all_auths that permits authorizations not present in the root invocation [1][2]. This is specifically useful for testing contracts that perform non-atomic cross-contract calls or those that do not use root-level authorization [1]. 3. mock_auths(&[MockAuth]): Allows for precise, granular mocking where only specific, matching authorization invocations succeed [1][4]. Testing Best Practices: To ensure security, mock_all_auths should ideally be paired with env.auths assertions [5][4]. By asserting against the environment's recorded authorization tree after a contract call, developers can verify that the contract actually performed the required authorization checks with the expected arguments, preventing tests from passing when authorization is missing [1][5][4]. Top results: [1], [5], [4], [3]
Citations:
- 1: https://docs.rs/soroban-sdk/latest/soroban_sdk/struct.Env.html
- 2: https://docs.rs/soroban-sdk/latest/soroban%5Fsdk/token/struct.TokenClient.html
- 3: https://developers.stellar.org/docs/build/smart-contracts/example-contracts/auth
- 4: https://github.com/stellar/stellar-dev-skill/blob/main/skills/smart-contracts/testing.md
- 5: https://developers.stellar.org/docs/build/guides/testing/test-contract-auth
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set -euo pipefail
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git ls-files | grep -F 'contracts/payment-stream/src/test.rs' || true
echo
echo "Relevant test section:"
sed -n '340,470p' contracts/payment-stream/src/test.rs | cat -n -v
echo
echo "Search for generated try_set_fee_tiers usage/client definitions:"
rg -n "try_set_fee_tiers|set_fee_tiers|MockAuth|set_auths|mock_all_auths|assert_auth" contracts/payment-stream/src/test.rs contracts/payment-stream -g '*.rs' || true
echo
echo "Cargo/soroban-sdk versions:"
rg -n 'soroban-sdk|soroban-spec|stellar' Cargo.toml contracts/payment-stream/Cargo.toml 2>/dev/null || true
echo
echo "Dependency specs if any:"
fd -a 'Cargo.toml|Cargo.lock' . | sed 's#^\./##' | head -20Repository: Fundable-Protocol/stellar_client_os
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sed -n '720,910p' contracts/payment-stream/src/lib.rs | cat -n -v
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echo "Client/generated try methods or generated-client usages:"
rg -n "pub type .*Client|struct .*Client|impl.*Client|try_[a-zA-Z0-9_]+|set_authority|set_fee_tiers|require_auth" contracts/payment-stream/src/lib.rs contracts/payment-stream/src/test.rs || trueRepository: Fundable-Protocol/stellar_client_os
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#!/bin/bash
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echo "CWD and root files:"
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echo
echo "Find top-level Cargo.toml:"
fd -a 'Cargo\.toml$' . | sed 's#^\./##' | sort
echo
echo "Root Cargo.toml relevant deps:"
ROOT_CARGO="$(git rev-parse --show-toplevel)/Cargo.toml"
sed -n '1,160p' "$ROOT_CARGO" | cat -n
echo
echo "Payment stream src top outline/imports:"
sed -n '1,80p' contracts/payment-stream/src/lib.rs | cat -n -v
echo
echo "Payment stream error/set_authority/set_fee_tiers:"
rg -n "enum .*Error|pub (type )?type .*Error|pub (struct )?struct .*Error|set_authority|set_fee_tiers|require_auth_for_args|require_auth|TierFeeNotMonotonic|InvalidTierConfiguration|Unauthorized" contracts/payment-stream/src/lib.rs | head -200
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echo "Lib relevant ranges around errors and fee tiers:"
rg -n "pub fn set_fee_tiers|pub fn set_authority|TierFeeNotMonotonic|InvalidTierConfiguration|Unauthorized" contracts/payment-stream/src/lib.rs -n
RANGES
set_fee=
rg -n "pub fn set_fee_tiers" contracts/payment-stream/src/lib.rsRepository: Fundable-Protocol/stellar_client_os
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sed -n '1,120p' contracts/payment-stream/Cargo.toml | cat -n
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echo "Payment stream lib imports/types/error definitions:"
rg -n "pub mod|pub use|contracttype|contractimpl|Error|Unauthorized|set_authority|set_fee_tiers|require_auth_for_args|try_[A-Za-z0-9_]+|pub fn [A-Za-z0-9_]+" contracts/payment-stream/src/lib.rs | head -250
echo
echo "Set fee tiers and admin auth implementation:"
python3 - <<'PY'
from pathlib import Path
p=Path("contracts/payment-stream/src/lib.rs")
text=p.read_text()
for pat in ["fn set_fee_tiers", "fn set_authority", "require_auth_for_args", "Unauthorized"]:
idx=text.find(pat)
print(f"\n{'='*40} {pat!r} {'='*40}")
line=text.count('\n',0,idx)+1
print(f"line {line}")
start=max(0, idx-900) if idx!=-1 else 0
end=min(len(text), idx+2200) if idx!=-1 else len(text)
print(text[start:end])
PYRepository: Fundable-Protocol/stellar_client_os
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echo "Payment stream Cargo.toml:"
sed -n '1,120p' /home/jailuser/git/contracts/payment-stream/Cargo.toml | cat -n
echo
echo "Payment stream lib relevant code:"
python3 - <<'PY'
from pathlib import Path
p=Path("/home/jailuser/git/contracts/payment-stream/src/lib.rs")
text=p.read_text()
for pat in ["fn set_fee_tiers", "fn set_authority", "require_auth_for_args", "Unauthorized", "InvalidTierConfiguration", "TierFeeNotMonotonic"]:
idx=text.find(pat)
print(f"\n{'='*40} {pat!r} {'='*40}")
line=text.count('\n',0,idx)+1 if idx!=-1 else None
print(f"line {line}")
if idx == -1:
continue
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echo "Payment stream Cargo.toml:"
cat /home/jailuser/git/contracts/payment-stream/Cargo.toml
echo
echo "Relevant lib code snippets:"
python3 - <<'PY'
from pathlib import Path
p=Path("/home/jailuser/git/contracts/payment-stream/src/lib.rs")
text=p.read_text().splitlines(keepends=True)
patterns=[
"fn set_fee_tiers",
"fn set_authority",
"require_auth_for_args",
"Unauthorized",
"InvalidTierConfiguration",
"TierFeeNotMonotonic",
]
for pat in patterns:
print(f"\n===== {pat} =====")
for i, ln in enumerate(text, 1):
if pat in ln:
start=max(1,i-25); end=min(len(text),i+80)
for j in range(start,end+1):
print(f"{j:5d}: {text[j-1].rstrip()}")
break
else:
print("not found")
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Assert the authorization error explicitly.
mock_all_auths() is active from the test setup, and mock_auth only mocks the non-admin invoke inside catch_unwind; a bare assert!(result.is_err()) then only proves set_fee_tiers panicked for that mock, not that the admin authorization check rejected it. Use the generated try_set_fee_tiers and assert Error::Unauthorized, or assert the mocked admin auth is the one required by admin.require_auth().
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
In `@contracts/payment-stream/src/test.rs` around lines 386 - 400, Update the
authorization assertion around set_fee_tiers to verify the specific
Error::Unauthorized result rather than only checking for a panic. Prefer the
generated try_set_fee_tiers client method and assert its returned error, or
explicitly mock the admin authorization required by admin.require_auth() while
preserving the existing non-admin rejection scenario.
| let large_amount = i128::MAX / 2; | ||
| let stream_id = client.create_stream( | ||
| &sender, | ||
| &donor, | ||
| &recipient, | ||
| &token, | ||
| &1000, | ||
| &1000, | ||
| &large_amount, | ||
| &large_amount, | ||
| &0, | ||
| &100, | ||
| ); | ||
|
|
||
| env.ledger().set_timestamp(50); | ||
|
|
||
| let withdrawable = client.withdrawable_amount(&stream_id); | ||
| client.withdraw_max(&stream_id); | ||
| // Cumulative volume should be recorded safely | ||
| let volume = client.get_donor_cumulative_volume(&donor); | ||
| assert_eq!(volume, large_amount); | ||
|
|
||
| // Check metrics | ||
| let stream_metrics = client.get_stream_metrics(&stream_id); | ||
| env.ledger().set_timestamp(50); | ||
| let available = client.withdrawable_amount(&stream_id); | ||
|
|
||
| assert_eq!(stream_metrics.total_withdrawn, withdrawable); | ||
| assert_eq!(stream_metrics.withdrawal_count, 1); | ||
| } | ||
| // Withdraw should work with large amounts | ||
| client.withdraw(&stream_id, &available); |
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🩺 Stability & Availability | 🟠 Major | 🏗️ Heavy lift
🧩 Analysis chain
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#!/bin/bash
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sed -n '240,285p' contracts/payment-stream/src/lib.rs
sed -n '555,585p' contracts/payment-stream/src/lib.rs
echo "== test relevant section =="
sed -n '535,590p' contracts/payment-stream/src/test.rs
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#!/bin/bash
set -euo pipefail
echo "== Rust checked overflow behavior probe =="
rustc --version
cat >/tmp/overflow_probe.rs <<'RS'
#[panic_handler]
fn panic(_info: &core::panic::PanicInfo) -> ! {
loop {}
}
fn main() {
let total_amount: i128 = i128::MAX / 2;
let elapsed: i128 = 50;
let duration: i128 = 100;
let vested = (total_amount * elapsed) / duration;
println!("{}", vested);
}
RS
if rustc -C panic=abort /tmp/overflow_probe.rs -o /tmp/overflow_probe 2>&1; then
if /tmp/overflow_probe; then
echo "NO PANIC: product computed without overflow"
else
echo "PANIC: product overflow/abort"
fi
else
echo "could not compile/execute overflow probe"
fiRepository: Fundable-Protocol/stellar_client_os
Length of output: 463
🌐 Web query:
Rust checked unsigned integer overflow panic at runtime debug release
💡 Result:
In Rust, the runtime behavior of integer overflow depends on the compilation profile, which is typically controlled via Cargo [1][2]. Debug Mode (Default for dev profile): By default, Rust enables runtime integer overflow checks in debug builds [3][4]. If an arithmetic operation (such as addition, subtraction, or multiplication) results in an overflow, the program will panic at runtime [5][3][2]. Release Mode (Default for release profile): By default, Rust disables these runtime checks in release builds to maximize performance [3][1][4]. In the event of an overflow, the operation will silently wrap using two's complement arithmetic [5][3][2]. Configuration and Overrides: You can explicitly control this behavior regardless of the build profile by configuring the overflow-checks setting in your Cargo.toml file [1][2]. For example, to enable overflow checks in release mode, add the following [2]: [profile.release] overflow-checks = true Conversely, you can disable them in debug mode by setting overflow-checks = false under [profile.dev] [4]. Explicit Alternatives: Because relying on default behaviors can lead to inconsistent results, it is considered best practice to use explicit methods when the possibility of overflow is known [2]. The standard library provides several methods for each integer type to handle overflow intentionally [6][7]: - checked_* (e.g., checked_add): Returns None if an overflow occurs, allowing you to handle the error gracefully [6][7]. - wrapping_* (e.g., wrapping_add): Always performs two's complement wrapping [6][7]. - saturating_* (e.g., saturating_add): Returns the maximum or minimum value of the type instead of wrapping [2]. - strict_* (e.g., strict_add): Always panics on overflow, regardless of compilation profile settings [6][7].
Citations:
- 1: https://dirname.github.io/rust-std-doc/cargo/reference/profiles.html
- 2: https://anssi-fr.github.io/rust-guide/integer.html
- 3: https://huonw.github.io/blog/2016/04/myths-and-legends-about-integer-overflow-in-rust/
- 4: https://www.0xatticus.com/posts/debug_performances/
- 5: https://doc.rust-lang.org/stable/reference/behavior-not-considered-unsafe.html
- 6: https://doc.rust-lang.org/stable/core/primitive.u8.html
- 7: https://doc.rust-lang.org/std/primitive.u32.html
Avoid unchecked vesting arithmetic before dividing out elapsed time.
withdrawable_amount computes (stream.total_amount * elapsed as i128) / duration as i128, so total_amount = i128::MAX / 2 with elapsed = 50 can overflow/underflow before the division. Also protocol_metrics.total_tokens_streamed += total_amount is unchecked. Use checked arithmetic here, with a mul-div fallback for the vesting calculation, or keep this test’s magnitude below the overflow boundary.
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
In `@contracts/payment-stream/src/test.rs` around lines 562 - 581, The
large-amount test exposes unchecked arithmetic in withdrawable_amount and
protocol_metrics.total_tokens_streamed. Update the vesting calculation to use
checked multiplication with a safe mul-div fallback before dividing by duration,
and use checked addition for cumulative streamed tokens; preserve correct
withdrawal behavior for large values without overflow.
| env.ledger().set_timestamp(100); | ||
|
|
||
| // Pause stream | ||
| client.pause_stream(&stream_id); | ||
| client.withdraw_max(&stream_id); | ||
|
|
||
| // Check metrics | ||
| let stream_metrics = client.get_stream_metrics(&stream_id); | ||
| assert_eq!(stream_metrics.pause_count, 1); | ||
| let stream = client.get_stream(&stream_id); | ||
| assert_eq!(stream.status, StreamStatus::Completed); | ||
|
|
||
| // Check protocol metrics | ||
| let protocol_metrics = client.get_protocol_metrics(); | ||
| assert_eq!(protocol_metrics.total_active_streams, 0); | ||
| let token_client = token::Client::new(&env, &token); | ||
| assert_eq!(token_client.balance(&recipient), 1000); | ||
| } |
There was a problem hiding this comment.
🎯 Functional Correctness | 🔴 Critical | ⚡ Quick win
Stale zero-fee assertion: default tiers now charge 500 bps.
initialize(..., &0) no longer means "no fee" — calculate_protocol_fee uses the default tiers, so tier 0 (500 bps) applies. Withdrawing 1000 yields a 50 fee, so the recipient receives 950. The same stale expectation exists in test_withdraw at Line 129 (asserts 300; actual net is 285).
💚 Proposed fix
let token_client = token::Client::new(&env, &token);
- assert_eq!(token_client.balance(&recipient), 1000);
+ // Tier 0 default is 500 bps: fee = 1000 * 500 / 10000 = 50
+ assert_eq!(token_client.balance(&recipient), 950);
+ assert_eq!(token_client.balance(&fee_collector), 50);📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| env.ledger().set_timestamp(100); | |
| // Pause stream | |
| client.pause_stream(&stream_id); | |
| client.withdraw_max(&stream_id); | |
| // Check metrics | |
| let stream_metrics = client.get_stream_metrics(&stream_id); | |
| assert_eq!(stream_metrics.pause_count, 1); | |
| let stream = client.get_stream(&stream_id); | |
| assert_eq!(stream.status, StreamStatus::Completed); | |
| // Check protocol metrics | |
| let protocol_metrics = client.get_protocol_metrics(); | |
| assert_eq!(protocol_metrics.total_active_streams, 0); | |
| let token_client = token::Client::new(&env, &token); | |
| assert_eq!(token_client.balance(&recipient), 1000); | |
| } | |
| env.ledger().set_timestamp(100); | |
| client.withdraw_max(&stream_id); | |
| let stream = client.get_stream(&stream_id); | |
| assert_eq!(stream.status, StreamStatus::Completed); | |
| let token_client = token::Client::new(&env, &token); | |
| // Tier 0 default is 500 bps: fee = 1000 * 500 / 10000 = 50 | |
| assert_eq!(token_client.balance(&recipient), 950); | |
| assert_eq!(token_client.balance(&fee_collector), 50); | |
| } |
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
In `@contracts/payment-stream/src/test.rs` around lines 649 - 658, Update the
withdrawal balance assertions in the affected test and test_withdraw to reflect
the default 500 bps protocol fee: expect 950 instead of 1000 for a 1000
withdrawal, and 285 instead of 300 for the existing 300 assertion. Leave the
withdrawal behavior and other assertions unchanged.
| token_admin.mint(&sender, &1000); | ||
|
|
||
| let _stream_id1 = client.create_stream( | ||
| let stream_id = client.create_stream( | ||
| &sender, | ||
| &recipient1, | ||
| &recipient, | ||
| &token, | ||
| &1000, | ||
| &1000, | ||
| &500, | ||
| &0, | ||
| &100, | ||
| ); | ||
|
|
||
| let _stream_id2 = client.create_stream( | ||
| &sender, | ||
| &recipient2, | ||
| &token, | ||
| &2000, | ||
| &2000, | ||
| &0, | ||
| &100, | ||
| ); | ||
| client.cancel_stream(&stream_id); | ||
|
|
||
| let _stream_id3 = client.create_stream( | ||
| &sender, | ||
| &recipient3, | ||
| &token, | ||
| &3000, | ||
| &3000, | ||
| &0, | ||
| &100, | ||
| ); | ||
| let stream = client.get_stream(&stream_id); | ||
| assert_eq!(stream.status, StreamStatus::Canceled); | ||
|
|
||
| // Check protocol metrics | ||
| let protocol_metrics = client.get_protocol_metrics(); | ||
|
|
||
| assert_eq!(protocol_metrics.total_active_streams, 3); | ||
| assert_eq!(protocol_metrics.total_tokens_streamed, 6000); | ||
| assert_eq!(protocol_metrics.total_streams_created, 3); | ||
| let token_client = token::Client::new(&env, &token); | ||
| // Sender should receive refund of remaining balance (500) | ||
| assert_eq!(token_client.balance(&sender), 500); | ||
| } |
There was a problem hiding this comment.
🎯 Functional Correctness | 🔴 Critical | ⚡ Quick win
Refund assertion is off by the escrowed amount.
The sender is minted 1000, escrows initial_amount = 500 at creation (balance 500), then cancel_stream refunds the full remaining 500 — ending balance is 1000, not 500. The comment on Line 810 describes the refund correctly, but the assertion contradicts it.
💚 Proposed fix
let token_client = token::Client::new(&env, &token);
- // Sender should receive refund of remaining balance (500)
- assert_eq!(token_client.balance(&sender), 500);
+ // Sender escrowed 500 and is refunded the full remaining 500
+ assert_eq!(token_client.balance(&sender), 1000);
+ assert_eq!(token_client.balance(&contract_id), 0);📝 Committable suggestion
‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.
| token_admin.mint(&sender, &1000); | |
| let _stream_id1 = client.create_stream( | |
| let stream_id = client.create_stream( | |
| &sender, | |
| &recipient1, | |
| &recipient, | |
| &token, | |
| &1000, | |
| &1000, | |
| &500, | |
| &0, | |
| &100, | |
| ); | |
| let _stream_id2 = client.create_stream( | |
| &sender, | |
| &recipient2, | |
| &token, | |
| &2000, | |
| &2000, | |
| &0, | |
| &100, | |
| ); | |
| client.cancel_stream(&stream_id); | |
| let _stream_id3 = client.create_stream( | |
| &sender, | |
| &recipient3, | |
| &token, | |
| &3000, | |
| &3000, | |
| &0, | |
| &100, | |
| ); | |
| let stream = client.get_stream(&stream_id); | |
| assert_eq!(stream.status, StreamStatus::Canceled); | |
| // Check protocol metrics | |
| let protocol_metrics = client.get_protocol_metrics(); | |
| assert_eq!(protocol_metrics.total_active_streams, 3); | |
| assert_eq!(protocol_metrics.total_tokens_streamed, 6000); | |
| assert_eq!(protocol_metrics.total_streams_created, 3); | |
| let token_client = token::Client::new(&env, &token); | |
| // Sender should receive refund of remaining balance (500) | |
| assert_eq!(token_client.balance(&sender), 500); | |
| } | |
| token_admin.mint(&sender, &1000); | |
| let stream_id = client.create_stream( | |
| &sender, | |
| &recipient, | |
| &token, | |
| &1000, | |
| &500, | |
| &0, | |
| &100, | |
| ); | |
| client.cancel_stream(&stream_id); | |
| let stream = client.get_stream(&stream_id); | |
| assert_eq!(stream.status, StreamStatus::Canceled); | |
| let token_client = token::Client::new(&env, &token); | |
| // Sender escrowed 500 and is refunded the full remaining 500 | |
| assert_eq!(token_client.balance(&sender), 1000); | |
| assert_eq!(token_client.balance(&contract_id), 0); | |
| } |
🤖 Prompt for AI Agents
Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.
In `@contracts/payment-stream/src/test.rs` around lines 792 - 812, Update the
final balance assertion in the cancel-stream test around client.cancel_stream
and token_client.balance so it expects the sender’s full 1000-token balance
after the 500-token escrow is refunded; keep the existing refund comment and
stream status assertion unchanged.
|
Hello @Idrhas , any update ?? |
|
dont forget to offramp using https://stellar.fundable.finance/offramp its fast, free and p2p rates |
1 similar comment
|
dont forget to offramp using https://stellar.fundable.finance/offramp its fast, free and p2p rates |
|
@Idrhas , conflict has been resolved, please chek.. |
3 participants
Dynamic Fee Tier System Implementation
Issue: #512
Branch: feature/dynamic-fee-tiers
closes #512
Summary
Implemented a complete, production-ready dynamic fee tier system for the Soroban payment-stream contract that reduces protocol streaming fees based on a donor's cumulative stream volume. This feature incentivizes high-volume ecosystem donors through a configurable, monotonically-enforced tiered fee structure.
Changes
Core Implementation
New Data Structure:
FeeTierNew Error Variants (Error Enum)
InvalidTierConfiguration = 17: Tier thresholds not properly ordered or first tier doesn't start at 0TierFeeNotMonotonic = 18: Fee rates not monotonically non-increasingNew Public Functions
set_fee_tiers(env: Env, tiers: Vec<FeeTier>)require_auth()on adminget_fee_tiers(env: Env) -> Vec<FeeTier>get_donor_cumulative_volume(env: Env, donor: Address) -> i128Modified Functions
create_stream(): Now tracks cumulative volume per donor (keyed by(Symbol("donor_volume"), donor_address))calculate_protocol_fee(env: &Env, donor: &Address, amount: i128) -> i128:donorparameter to look up cumulative volumewithdraw(): Updated to pass donor address to fee calculationStorage
fee_tiers(Vec) — contains tier configuration(Symbol("donor_volume"), donor_address)— per-donor cumulative volume (i128)Default Tier Structure
Initialized on contract creation:
Note: These defaults are a starting proposal and should be reviewed and approved by the product/business team before release. Thresholds and fees can be adjusted via
set_fee_tiers()without contract redeployment.Design Decisions
Volume Tracking: All-Time Cumulative
Decision: Volume is tracked as all-time cumulative per donor across the entire contract history, not windowed (e.g., rolling 30-day).
Reasoning:
Implication: Once a donor reaches a tier threshold, they maintain that tier for all future streams, even if they create no new streams for a long time. Storage TTL management ensures donor volume entries won't unexpectedly expire and reset tier status.
Volume Definition: Stream Total Amount at Creation
Decision: Cumulative volume increases when a stream is created, using the stream's
total_amount.Reasoning:
Fee Monotonicity: Strict Enforcement
Decision: Tier configuration validation enforces that fee rates are monotonically non-increasing — fees can only stay the same or decrease as volume tier increases, never increase.
Implementation:
set_fee_tiers()rejects any tier configuration where a higher-threshold tier has a higher fee rate than a lower-threshold tier. This is a protocol-level invariant enforced at tier configuration time.Why: Guarantees that the incentive structure is always correct — higher volume always results in equal or better (lower) fees. Prevents misconfiguration that could accidentally penalize high-volume donors.
Storage TTL & Expiry
Decision: Per-donor cumulative volume entries use the same TTL management as per-stream storage (
LEDGER_THRESHOLD = 518400,LEDGER_BUMP = 535680, ~30–31 days).Reasoning:
Authorization
set_fee_tiers): Requiresadmin.require_auth()— only admin can reconfigure feesTesting
Comprehensive test suite covering:
Tier Selection (Success Cases)
test_withdraw_with_fee_tier_0(): Donor below first threshold pays base fee (tier 0)test_withdraw_with_fee_tier_1(): Donor above 50,000 qualifies for tier 1 (2.5%)test_withdraw_with_fee_tier_2(): Donor above 500,000 qualifies for tier 2 (1%)Volume Accumulation
test_cumulative_volume_across_multiple_streams(): Volume correctly sums across multiple streamstest_independent_donor_volumes(): Multiple donors' volumes tracked independentlyTier Configuration
test_get_fee_tiers(): Retrieves configured tier structuretest_set_fee_tiers_admin_only(): Non-admin attempt rejectedtest_set_fee_tiers_non_monotonic_fees(): Rejects non-monotonic fee configurationtest_set_fee_tiers_first_tier_threshold_zero(): Enforces first tier threshold is 0test_default_tiers_initialized_on_init(): Verifies default tiers are set upEdge Cases & Boundary Conditions
test_fee_tier_boundary_exact(): Donor at exactly threshold amount qualifies for that tiertest_arithmetic_overflow_checked(): Large amounts handled safely with checked arithmetictest_withdraw_with_fee_tier_0(): Fee calculation is correctExisting Functionality (Regression)
test_create_stream(): Stream creation still workstest_withdrawable_amount(): Vesting logic unchangedtest_withdraw(): Withdrawal still workstest_withdraw_max(): Max withdrawal still workstest_pause_stream(): Pause still workstest_resume_stream(): Resume still workstest_set_delegate(): Delegation still workstest_cancel_stream(): Cancellation and refunds still workBuild & Verification
Compilation:
Testing:
cargo testCode Quality
checked_add()to prevent overflowUpgrade Compatibility
set_fee_tiers()with desired configuration after upgrade if different from defaultsOutstanding Items for Product Review
set_fee_tiers()as needed.Files Changed
contracts/payment-stream/src/lib.rs: Core implementationcontracts/payment-stream/src/test.rs: Comprehensive test suiteChecklist
cargo build --target wasm32-unknown-unknowncargo testNext Steps
set_fee_tiers()if neededSummary by CodeRabbit
New Features
Bug Fixes