Trace ID

trace_e04b6e8e-8d72-4c63-a519-b9b67d66b44b

failed

Amount: 0.00000045 CKB; 45 Shannon
Mode: fiber-rpc
Latency: 31ms
Failure stage: fiber_rpc_error
Sender: fiber-rpc-node
Receiver: 03c93e...298d

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
Add outbound route capacity on the constrained hop
Use an alternate route with enough capacity for the full payment

Failure Timeline

Lifecycle events captured in milliseconds.

5 events

0ms
request_receivedinfo
Live Fiber payment dry-run requested
24ms
node_infosuccess
Connected to Fiber Network Node RPC
24ms
channel_snapshotsuccess
Captured 1 live Fiber channels
24ms
graph_snapshotsuccess
Captured live Fiber graph snapshot
31ms
fiber_rpc_errorerror
Send payment error: Failed to build route, Insufficient balance: max outbound liquidity 0 is insufficient, required amount: 45

Live Replay-to-Fix

Recommended Fix Plan

Generated from the observed FNN failure. These changes are suggested, not executed; Live Verification records the real dry-run result.

smaller amount

Reduce amount to the largest successful replay amount

Suggested

Enter the corrected amount below with a fresh invoice or target pubkey, then verify against FNN.

Primary recommendation

increased outbound capacity

Add outbound route capacity on the constrained hop

Suggested

Apply the liquidity or channel change outside FiberTracebox, then verify against FNN with a fresh invoice or target pubkey.

alternate route

Use an alternate route with enough capacity for the full payment

Suggested

Apply this request or node configuration change, then verify against FNN with a fresh invoice or target pubkey.

Verify a change with FNN

Live Fiber Evidence

FNN-backed payment and channel proof

Captured from Fiber Network Node RPC during this trace.

FNN pubkey: [redacted]
FNN version: 0.9.0-rc5
Payment hash: not captured
FNN payment status: failed
Invoice status: not observed
Fee: unknown
Channel count: 1
Dry run: unknown

Channel	State	Enabled	Local balance	Remote balance	Peer
[redacted]	ChannelReady	true	[redacted]	[redacted]	[redacted]

Graph snapshot

Available, 0 nodes, 0 channels.

Live Verification

Verify the operator fix with FNN

Apply the recommended change to your test nodes, then run a new dry-run. The result is linked to this failure as real RPC evidence.

Recommended change: Reduce amount to the largest successful replay amount

Fresh Fiber invoice

Amount override (Shannon)Fee limit (Shannon)

API key

Dry-run is enforced by the server

Exportable Debug Report

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

# FiberTracebox Report

## Trace Summary

- Trace ID: trace_e04b6e8e-8d72-4c63-a519-b9b67d66b44b
- Payment status: failed
- Amount: 0.00000045 CKB (45 Shannon)
- Sender: fiber-rpc-node
- Receiver: 03c93e...298d
- Mode: fiber-rpc
- Latency: 31ms
- Failure time: 31ms
- 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: [redacted]
- 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: 45

| channel id | state | enabled | local balance | remote balance | peer pubkey |
| --- | --- | --- | --- | --- | --- |
| [redacted] | ChannelReady | true | [redacted] | [redacted] | [redacted] |

### 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 fix recommendations with changes verified only through a separate FNN dry-run
- Live mutation: no
- RPC methods observed: node_info, list_channels, graph_nodes, graph_channels, send_payment
- Observed failure stage: fiber_rpc_error
- Observed failure fingerprint: ROUTE_CAPACITY_INSUFFICIENT
- Failed RPC method: send_payment
- FNN error code: -32000
- Classification reason: FNN reported a route capacity, liquidity, balance, or max-HTLC constraint.
- Fiber RPC events come from configured FNN JSON-RPC calls.
- Dry-run mode requests route/payment checks without intentionally sending a new live payment.
- Live Replay-to-Fix recommendations are not execution evidence until a linked Live Verification dry-run is recorded.
- Live Verification uses a new server-enforced dry-run and never represents sandbox replay as live evidence.

## Timeline

| ms | stage | severity | message |
| --- | --- | --- | --- |
| 0 | request_received | info | Live Fiber payment dry-run requested |
| 24 | node_info | success | Connected to Fiber Network Node RPC |
| 24 | channel_snapshot | success | Captured 1 live Fiber channels |
| 24 | graph_snapshot | success | Captured live Fiber graph snapshot |
| 31 | fiber_rpc_error | error | Send payment error: Failed to build route, Insufficient balance: max outbound liquidity 0 is insufficient, required amount: 45 |

## Replay Results

| strategy | changed condition | result | latency ms | recommended |
| --- | --- | --- | --- | --- |
| Not executed | Live safety boundary | Suggested changes require FNN Live Verification | - | - |

## Live Replay-to-Fix Recommendations

These recommendations are derived from the observed FNN failure. They were not executed against the node.

| priority | strategy | suggested change | verification step |
| --- | --- | --- | --- |
| primary | smaller_amount | Reduce amount to the largest successful replay amount | Enter the corrected amount below with a fresh invoice or target pubkey, then verify against FNN. |
| alternative | increased_outbound_capacity | Add outbound route capacity on the constrained hop | Apply the liquidity or channel change outside FiberTracebox, then verify against FNN with a fresh invoice or target pubkey. |
| alternative | alternate_route | Use an alternate route with enough capacity for the full payment | Apply this request or node configuration change, then verify against FNN with a fresh invoice or target pubkey. |

## Replay-to-Fix Recommendation

Reduce amount to the largest successful replay amount This is a suggested live fix; verify it with a new server-enforced FNN dry-run.



Confidence: high

## Suggested Next Actions

- Reduce amount to the largest successful replay amount
- Add outbound route capacity on the constrained hop
- Use an alternate route with enough capacity for the full payment
- Apply the operator change on the test nodes, then run Live Verification with a fresh or corrected FNN dry-run.

## Mode Disclosure

Fiber RPC mode: live FNN evidence is captured from node, channel, graph, invoice, and payment RPC calls. Live Verification links a corrected FNN dry-run to the original failure without sending funds.