Rastir

LLM & Agent Observability for Python
One decorator per framework. Full visibility. No monkey-patching.

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What is Rastir?

Rastir gives you production observability for LLM agents — token usage, latency percentiles, cost tracking, tool call rates, error categories — as Prometheus metrics with Grafana dashboards.

Add one decorator to your LangGraph, CrewAI, LlamaIndex, ADK, or Strands workflow. Rastir auto-discovers LLMs, tools, and graph nodes inside the framework and wraps them for per-call tracing. No code rewrites. No vendor lock-in.

from rastir import configure, framework_agent

configure(service="my-app", push_url="http://localhost:8080")

@framework_agent
def run(graph_or_agent, prompt):
    return graph_or_agent.invoke(prompt)  # Works with any supported framework

That's it. @framework_agent auto-detects the framework from function arguments and instruments everything inside. Every LLM call, tool invocation, and node execution is now traced with metrics flowing to Prometheus.

You can also use framework-specific decorators for explicit control: @langgraph_agent, @crew_kickoff, @llamaindex_agent, @adk_agent, @strands_agent.

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Key Features

Feature	Description
One decorator per framework	@framework_agent (auto-detect), @langgraph_agent, @crew_kickoff, @llamaindex_agent, @adk_agent, @strands_agent
8 provider adapters	OpenAI, Azure OpenAI, Anthropic, Bedrock, Gemini, Cohere, Mistral, Groq — auto-detected from client module paths
Two-phase enrichment	Model/provider metadata captured from function args before the call, refined from response after. Survives API failures
MCP distributed tracing	wrap(session) propagates trace context across MCP tool boundaries — same trace_id links client and server
Cost observability	Per-model USD cost tracking with PricingRegistry, pricing profiles, cost histograms
Streaming TTFT	Time-To-First-Token measurement on streaming LLM calls
Guardrail tracking	Automatic AWS Bedrock guardrail violation metrics
Error normalisation	Exceptions mapped to 6 fixed categories: timeout, rate_limit, validation_error, provider_error, internal_error, unknown
Self-hosted collector	FastAPI server you own. Prometheus /metrics, in-memory trace store, OTLP export to Tempo/Jaeger
SRE budgets & burn rates	Error and cost budget tracking via Prometheus recording rules — SLO status, burn rates, days-to-exhaustion, all config-driven
7 Grafana dashboards	LLM Performance, Agent-Tool, Cost-TTFT, Evaluation, Guardrail, SRE Budgets, System Health
Generic wrap()	Instrument any object — Redis, databases, MCP sessions — without decorator access

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Framework Support at a Glance

All five frameworks work with @framework_agent (auto-detects the framework) or the dedicated decorator:

	LangGraph	CrewAI	LlamaIndex	ADK	Strands
Decorator	@langgraph_agent	@crew_kickoff	@llamaindex_agent	@adk_agent	@strands_agent
Agent span	Automatic	Automatic	Automatic	Automatic	Automatic
LLM tracing	Auto-discovered	Auto-discovered	Auto-discovered	Auto-discovered	Auto-discovered
Tool tracing	Auto-discovered	Auto-discovered	Auto-discovered	Auto-discovered	Auto-discovered
Node tracing	Automatic (all nodes)	N/A	N/A	N/A	N/A
MCP tools	Pass as normal tools	Native via mcps=[]	MCP tools auto-wrapped	Auto-discovered	Auto-discovered
User code	1 decorator	1 decorator	1 decorator	1 decorator	1 decorator

LangGraph

@langgraph_agent(agent_name="react_agent")
def run(graph, query):
    return graph.invoke({"messages": [("user", query)]})

react_agent (AGENT)
  ├── node:agent (TRACE)       ← every graph node traced
  │   └── langgraph.llm.gpt-4o.invoke (LLM)
  ├── node:tools (TRACE)
  │   └── langgraph.tool.search.invoke (TOOL)
  └── node:agent (TRACE)
      └── langgraph.llm.gpt-4o.invoke (LLM)

CrewAI

@crew_kickoff(agent_name="research_crew")
def run(crew):
    return crew.kickoff()

research_crew (AGENT)
  ├── crewai.Researcher.llm.call (LLM) — model, provider, tokens, cost
  ├── crewai.Researcher.tool.search (TOOL) — tool.input, tool.output
  │   └── mcpserver:search (TOOL)       ← server span via traceparent
  ├── crewai.Researcher.llm.call (LLM)
  └── crewai.Writer.llm.call (LLM)

LlamaIndex

from rastir import llamaindex_agent
from llama_index.core.agent import ReActAgent

agent = ReActAgent(llm=llm, tools=tools, streaming=False)

@llamaindex_agent(agent_name="qa_agent")
async def run(agent, query):
    return await agent.run(query)

qa_agent (AGENT)
├── llamaindex.ReActAgent.llm.achat (LLM) — model, provider, tokens, cost
├── search.acall (TOOL)                   — tool.input, tool.output
│   └── mcpserver:search (TOOL)           ← server span via traceparent
├── llamaindex.ReActAgent.llm.achat (LLM)
└── llamaindex.ReActAgent.llm.achat (LLM)

ADK

@adk_agent(agent_name="weather_agent")
async def run(runner, prompt):
    events = []
    async for event in runner.run_async(user_id="u1", session_id="s1",
        new_message=types.Content(role="user", parts=[types.Part(text=prompt)])):
        events.append(event)
    return events

weather_agent (AGENT)
├── LLM  gemini-2.0-flash
├── TOOL get_weather
└── LLM  gemini-2.0-flash

Strands

@strands_agent(agent_name="research_agent")
def run(agent, prompt):
    return agent(prompt)

research_agent (AGENT)
├── LLM  us.anthropic.claude-sonnet-4-20250514
├── TOOL search_tool
└── LLM  us.anthropic.claude-sonnet-4-20250514

→ Detailed framework documentation: LangGraph · CrewAI · LlamaIndex · ADK · Strands

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Supported Providers

Provider	Auto-detection	Tokens	Model	Streaming	Request-phase
OpenAI	✅	✅	✅	✅	✅
Azure OpenAI	✅	✅	✅	✅	✅
Anthropic	✅	✅	✅	✅	✅
AWS Bedrock	✅	✅	✅	✅	✅
Google Gemini	✅	✅	✅	✅	✅
Cohere	✅	✅	✅	—	✅
Mistral	✅	✅	✅	✅	✅
Groq	✅	✅	✅	✅	✅

Providers are auto-detected from LLM client module paths — no configuration needed. Each provider adapter extracts model name, token counts, and cost from the provider's native response format.

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Installation

pip install rastir              # Client library
pip install rastir[server]      # + Collector server
pip install rastir[all]         # Everything

Quick Start

from rastir import configure, agent, llm, trace

configure(service="my-app", push_url="http://localhost:8080")

@agent(agent_name="qa_bot")
def answer(query):
    return ask_llm(search(query))

@trace
def search(query):
    return vector_db.search(query)

@llm
def ask_llm(context):
    return openai.chat.completions.create(model="gpt-4o", messages=[...])

Start the collector:

rastir-server   # Prometheus metrics at :8080/metrics

What You Get in Prometheus

rastir_llm_calls_total{model="gpt-4o", provider="openai", agent="qa_bot"} 150
rastir_tokens_input_total{model="gpt-4o"} 25000
rastir_tokens_output_total{model="gpt-4o"} 8500
rastir_duration_seconds_bucket{span_type="llm", le="1.0"} 120
rastir_errors_total{span_type="llm", error_type="rate_limit"} 3
rastir_cost_total{model="gpt-4o", pricing_profile="prod"} 12.50
rastir_ttft_seconds_bucket{model="gpt-4o", le="0.5"} 95

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Architecture

Your Application                             Rastir Collector
┌────────────────────────────────┐           ┌────────────────────────────┐
│  @framework_agent (auto-detect)│   HTTP    │  FastAPI                   │
│  @langgraph_agent / @adk_agent │  ──────▸  │  ├── Prometheus /metrics   │
│  @crew_kickoff / @strands_agent│   spans   │  ├── Trace store /v1/traces│
│  @llamaindex_agent             │           │  ├── Sampling & backpressure│
│  @agent / @llm / wrap(obj)     │           │  └── OTLP → Tempo/Jaeger  │
└────────────────────────────────┘           └────────────────────────────┘

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Deployment

Rastir ships with ready-to-use deployment for local dev, 3 clouds (AWS, Azure, GCP), and Kubernetes:

Target	Tool	Command
Local	Docker Compose	cd deploy/docker && ./deploy.sh
AWS	Terraform (ECS Fargate)	cd deploy/terraform/aws && ./deploy.sh
Azure	Terraform (ACI)	cd deploy/terraform/azure && ./deploy.sh
GCP	Terraform (Cloud Run)	cd deploy/terraform/gcp && ./deploy.sh
Kubernetes	Helm	cd deploy/k8s && ./deploy.sh

Each deployment includes the full stack: Rastir Server + OTel Collector + Prometheus + Grafana. Traces go to Tempo (local/k8s), X-Ray (AWS), Application Insights (Azure), or Cloud Trace (GCP).

See Deployment Guide for details.

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Documentation

Full documentation at skamalj.github.io/rastir:

Section	Pages
Getting Started	Installation & Quick Start
Core	Decorators · Adapters · wrap() & MCP · MCP Tracing
Frameworks	LangGraph · CrewAI · LlamaIndex · ADK · Strands
Operations	Metrics · Dashboards · Server · Configuration
Deployment	Docker Compose · AWS · Azure · GCP · Kubernetes
Reference	Architecture · Environment Variables · Contributing Adapters

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License

MIT — see LICENSE for details.