RIFFT // OPERATOR CONSOLE // V0.42.1
SYS NOMINALSDK 0.42.1REGION US-WEST-2
UTC GRID 37.7749N 122.4194W
00/Mission brief
agent debugging platform · v0.42.1
● LiveAI Agent DebuggerMAST v1.0

Find where your
agent actually
broke.

Not the error — the handoff that caused it. Rifft traces bad state back to its origin, classifies the failure mode, and lets you replay from the exact broken handoff.

OR
Email
15MAST failure
modes classified
2.8send-to-end
replay time
7+frameworks
supported
Live demo — same trace every broken run shows you
rifft.dev · run_8a3f2c
LIVE
TRACE
·
TRACE
·
FAILURE
·
DIAGNOSED
·
FORKED
·
REPLAYED
·
run_8a3f2c5 spans2 agents
Open full trace →
Works with CrewAI · AutoGen · LangGraph · LlamaIndex · OTEL · custom stacks
01/Failure catalog
MAST taxonomy · 4 failure classes

The failures that
actually matter.

MAST-01·Rifft detects

Unverified Output

An agent passes ungrounded or hallucinated content to the next step without any validation gate.

> citation_url: None
> publisher accepted it anyway
MAST-02·Rifft detects

Tool Loop

An agent calls the same tool repeatedly on the same input, running until the context window fills.

> search("climate change") ×14
> terminated by token limit
MAST-03·Rifft detects

Handoff Mismatch

An agent sends a different schema than the next agent expects, causing a silent parse failure downstream.

> expected: {sources: string[]}
> received: {refs: object[]}
MAST-04·Rifft detects

Context Overflow

Accumulated context exceeds limits, causing truncation of instructions or prior reasoning mid-run.

> ctx: 128 041 / 128 000 tokens
> truncated system prompt at step 8
01/Quickstart
drop-in for the harness you already use

Five lines. No exporters, no collectors, no YAML.

Wrap your existing crew, graph, or chat manager. Rifft picks up handoffs, tool calls, and state mutations automatically.

Also: OpenAI Swarm, LlamaIndex, OTEL, custom stacks.
agent.py● connected · CrewAI
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# wrap your existing crew — no other changes
from rifft import trace
from crewai import Crew, Agent
@trace(agent_id="research")
def research(query):
crew = Crew(agents=[planner, researcher, publisher])
return crew.kickoff(query)
03/How it works
~5 minutes to first trace

From "why is this broken" to a passing replay, in three moves.

01

Drop in the SDK

One import wraps your agent harness. We pick up handoffs, tool calls, and state mutations automatically — no decorators on every function.

02

Trace the bad handoff

When a run fails, Rifft walks backwards through spans to find the first place the state went wrong. You see the cause, not the symptom.

03

Fork. Replay. Ship.

Replay from any span with patched inputs, validators, or an entirely new agent. Diff the runs side-by-side. Promote the fix.

STEP 01 · agent.py
from rifft import trace

@trace(agent_id="research")
def run(query):
    crew = Crew(agents=[
        planner, researcher, publisher])
    return crew.kickoff(query)
4 lines added● auto-instrumented
04/The 2am test
/

Your prod agent failed at 2:14am. What you'd actually do.

— without rifft

Stare at 12k tokens of trace.

$ tail -f agent.log | grep ERROR
...
[ERR 02:14:33] Publisher: KeyError 'citation_url'
[INF 02:14:29] Researcher: returned 4 sources
[INF 02:14:18] Retriever: returned 12 docs
[INF 02:13:57] Run started

you: why is publisher failing
you: whose citation_url is missing
↳ 47 minutes later: rerun the whole crew with prints
— with rifft

Open the run. See the cause.

$ rifft inspect run_8a3f2c

root cause → Researcher span
  └─ unverified citation passed to Publisher

classified as MAST-01 unverified output
  └─ similar to 3 prior runs

rifft replay run_8a3f2c --from researcher
↳ 2.8s later: green. ship it.
05/Integrations
drop-in for your existing stack
CA
CrewAI
LG
LangGraph
AG
AutoGen
LI
LlamaIndex
OT
OTEL
AI
Vercel AI
OS
OpenAI Swarm
SK
Semantic Kernel
DS
DSPy
HF
HuggingFace
BF
BeeAgent
++
Custom OTEL
06/Pricing
start free · upgrade when you need to
Free
$0/ month

For individual developers exploring Rifft.

  • 50K spans/month
  • 14-day retention
  • Causal graph & MAST classification
  • 1 workspace
Start free →
MOST POPULAR
Pro
$49/ month

For teams running agents in production.

  • 500K spans/month
  • 90-day retention
  • Fork mode & replay
  • Unlimited team members
  • Slack & email alerts
  • NL failure explanations
Start with Pro →
Scale
$149/ month

For high-volume pipelines and larger orgs.

  • 2M spans/month
  • 1-year retention
  • Everything in Pro
  • Automatic regression detection
  • Priority support
  • $5 per 100K spans above 2M
Get started →
07/Why Rifft
built for the failures that are expensive to miss
PRINCIPLE 01

Find the Real Starting Point

When the visible failure is downstream from the actual cause, Rifft walks backwards through spans to the handoff that introduced bad state — not the error message you actually saw.

PRINCIPLE 02

Understand the Failure Type

MAST classification turns raw trace noise into recognizable patterns: unverified output, tool loop, handoff mismatch, context overflow. Pattern-match, not log-grep.

PRINCIPLE 03

Retry From the Break

Fork from any handoff, keep the successful steps, and test a fix without rerunning the whole workflow. Promote the replay to main.

08/vs LangSmith / Langfuse
as of June 2026
Feature
Rifft
LangSmith
Langfuse
Causal chain attribution
MAST failure classification
Fork & replay from any handoff
Multi-agent trace view
Partial
Partial
General LLM tracing
Self-hosted option
Free tier
50K spans/mo
5K traces/mo
50K events/mo
Comparison reflects public product information as of June 2026. If we missed something, tell us →

Start debugging.
First trace in five minutes.

Drop in four lines of Python or TypeScript. Rifft instruments your agent harness, streams spans to the collector, and shows you the first causal chain before you close the terminal.

No credit card required
50K spans free every month
Works with your existing stack
Cancel anytime