Trace ID

trace_c2bbcf1f-55d8-419a-8bf6-30ca1bc24187

replayed

Amount: 1,000 CKB
Mode: fiber-rpc
Latency: 18ms
Failure stage: fiber_rpc_error
Sender: fiber-rpc-node
Receiver: 0360779e54f1b2f380fe6889223ccf240c857bfebacd3c197a8d0124e9ab5d0484

ROUTE_CAPACITY_INSUFFICIENT

Route capacity insufficient

A route was discovered, but the available forwarding capacity was lower than the requested payment amount.

Likely Causes

Outbound liquidity is below the payment size
One hop has a lower max HTLC than the payment amount
The route can carry smaller payments but not this full amount

Suggested Fixes

Reduce amount to the largest successful replay amount
Split the payment across multiple paths
Add outbound route capacity on the constrained hop

Failure Timeline

Lifecycle events captured in milliseconds.

5 events

0ms
request_receivedinfo
Live Fiber payment dry-run requested
12ms
node_infosuccess
Connected to Fiber Network Node RPC
12ms
channel_snapshotsuccess
Captured 1 live Fiber channels
12ms
graph_snapshotsuccess
Captured live Fiber graph snapshot
18ms
fiber_rpc_errorerror
Send payment error: Failed to build route, Insufficient balance: max outbound liquidity 0 is insufficient, required amount: 1000

Replay-to-Fix Results

same_conditions

Original amount, route, peer state, fee limit, timeout, and asset unchanged

failed

The original failure reproduces under the same conditions, confirming the fingerprint is stable.

25ms

reduced_amount_80

Reduced amount to 80%: 800 CKB

failed

800 CKB still exceeds the constrained route capacity, so the payment fails again.

44ms

reduced_amount_64

Reduced amount to 64%: 640 CKB

success

640 CKB matches the observed maximum forwardable capacity and settles.

38ms

increased_outbound_capacity

Added exact outbound route capacity deficit: 360 CKB

success

Adding 360 CKB raises route capacity to the original payment amount and removes the constrained hop.

42ms

alternate_route

Selected alternate route excluding the failing condition

success

A route with different hops avoids the original failure point with slightly higher latency.

73ms

split_payment

Split payment into 500 CKB + 500 CKB

success

Splitting widens eligible paths and lowers per-route capacity pressure while preserving the original total amount.

54msSmallest-fix recommendation

Live Fiber Evidence

FNN-backed payment and channel proof

Captured from Fiber Network Node RPC during this trace.

FNN pubkey: 025cb868b35b602d1330597066a123e161ddd91bc556fe3c14b8e8a63caf1cb849
FNN version: 0.9.0-rc5
Payment hash: not captured
FNN payment status: replayed
Invoice status: not observed
Fee: unknown
Channel count: 1
Dry run: unknown

Channel	State	Enabled	Local balance	Remote balance	Peer
0x37bbbcd2bb99f9acef9af51604c94ea25ca9d4d85e415b3a404015a9ba44204a	ChannelReady	true	0xe6868f0d00 (990,100,000,000 raw units)	0x5f5e100 (100,000,000 raw units)	02813acb2d49ec3f229051294b3eb901b4ba9b03d90b08a4cc19e49ba4f5bb76df

Graph snapshot

Available, 0 nodes, 0 channels.

Exportable Debug Report

Markdown and JSON report output for trace reviews and operator handoff.

# FiberTracebox Report

## Trace Summary

- Trace ID: trace_c2bbcf1f-55d8-419a-8bf6-30ca1bc24187
- Payment status: replayed
- Amount: 1,000 CKB
- Sender: fiber-rpc-node
- Receiver: 0360779e54f1b2f380fe6889223ccf240c857bfebacd3c197a8d0124e9ab5d0484
- Mode: fiber-rpc
- Latency: 18ms
- Failure time: 18ms
- Failure stage: fiber_rpc_error
- Failure fingerprint: ROUTE_CAPACITY_INSUFFICIENT


## Root Cause

A route was discovered, but the available forwarding capacity was lower than the requested payment amount.

## Live Fiber Evidence

- FNN node pubkey: 025cb868b35b602d1330597066a123e161ddd91bc556fe3c14b8e8a63caf1cb849
- FNN version: 0.9.0-rc5
- FNN channel count: 1
- FNN peers count: 0x2
- Failed RPC method: send_payment
- FNN error code: -32000
- Classified failure: ROUTE_CAPACITY_INSUFFICIENT
- Classification reason: FNN reported a route capacity, liquidity, balance, or max-HTLC constraint.
- FNN error message: Send payment error: Failed to build route, Insufficient balance: max outbound liquidity 0 is insufficient, required amount: 1000

| channel id | state | enabled | local balance | remote balance | peer pubkey |
| --- | --- | --- | --- | --- | --- |
| 0x37bbbcd2bb99f9acef9af51604c94ea25ca9d4d85e415b3a404015a9ba44204a | ChannelReady | true | 0xe6868f0d00 (990,100,000,000 raw units) | 0x5f5e100 (100,000,000 raw units) | 02813acb2d49ec3f229051294b3eb901b4ba9b03d90b08a4cc19e49ba4f5bb76df |

### Graph Snapshot

- Graph snapshot attempted: yes
- Graph snapshot available: yes
- Graph node count: 0
- Graph channel count: 0
- Receiver present in graph: no
- Usable captured ChannelReady channels: 1
- Public captured channels: 0


## Evidence Source

- Trace source: fiber-rpc
- Replay mode: live evidence capture only; replay changes are not executed against FNN
- Live mutation: no
- RPC methods observed: node_info, list_channels, graph_nodes, graph_channels, send_payment
- Observed failure: not applicable
- Fiber RPC events come from configured FNN JSON-RPC calls.
- Dry-run mode requests route/payment checks without intentionally sending a new live payment.
- Replay-to-Fix remains analytical for live traces because alternate live attempts can move funds or mutate channels.

## Timeline

| ms | stage | severity | message |
| --- | --- | --- | --- |
| 0 | request_received | info | Live Fiber payment dry-run requested |
| 12 | node_info | success | Connected to Fiber Network Node RPC |
| 12 | channel_snapshot | success | Captured 1 live Fiber channels |
| 12 | graph_snapshot | success | Captured live Fiber graph snapshot |
| 18 | fiber_rpc_error | error | Send payment error: Failed to build route, Insufficient balance: max outbound liquidity 0 is insufficient, required amount: 1000 |

## Replay Results

| strategy | changed condition | result | latency ms | recommended |
| --- | --- | --- | --- | --- |
| same_conditions | Original amount, route, peer state, fee limit, timeout, and asset unchanged | failed | 25 | no |
| reduced_amount_80 | Reduced amount to 80%: 800 CKB | failed | 44 | no |
| reduced_amount_64 | Reduced amount to 64%: 640 CKB | success | 38 | no |
| increased_outbound_capacity | Added exact outbound route capacity deficit: 360 CKB | success | 42 | no |
| alternate_route | Selected alternate route excluding the failing condition | success | 73 | no |
| split_payment | Split payment into 500 CKB + 500 CKB | success | 54 | yes |

## Smallest-Fix Recommendation

Smallest route-capacity fix: Split the payment into two 500 CKB parts, or reduce amount to 640 CKB.

If the operator controls liquidity, add at least 360 CKB outbound route capacity.

Confidence: high

## Suggested Next Actions

- Reduce amount to the largest successful replay amount
- Split the payment across multiple paths
- Add outbound route capacity on the constrained hop
- Split the payment into two 500 CKB parts, or reduce amount to 640 CKB.
- If the operator controls liquidity, add at least 360 CKB outbound route capacity.

## Mode Disclosure

Fiber RPC mode: live FNN evidence is captured from node, channel, graph, invoice, and payment RPC calls. Replay-to-Fix remains analytical for live traces because changing live route conditions can move funds or mutate channels.

Open JSON report