cd /news/ai-agents/we-built-a-flight-recorder-for-ai-co… · home topics ai-agents article
[ARTICLE · art-74052] src=dev.to ↗ pub= topic=ai-agents verified=true sentiment=· neutral

We Built a Flight Recorder for AI Coding Agents: Here's What SigNoz Taught Us About Watching Them Think

SigNoz built AXRAY, an observability layer for AI coding agents, using OpenTelemetry and SigNoz as its backbone. The system revealed that 78% of agent latency came from LLM thinking time, not Docker or shell commands, enabling targeted optimizations.

read4 min views1 publishedJul 26, 2026

Our AI agent was writing code, running tests, and opening pull requests, but I had absolutely no idea why some runs took 8 seconds while others took 45.

Was the LLM thinking too long?

Was it stuck retrying a failing shell command?

Was Docker slow?

I couldn't tell.

All I had was a spinner and a final result.

That gap between knowing an agent is doing something and actually knowing what it's doing is exactly why we built AXRAY, using SigNoz as our observability backbone.

This is the story of building it, the architecture behind it, and the deployment pitfalls that nearly broke everything.

Autonomous coding agents don't behave like traditional microservices.

A single agent turn might involve:

Every one of those actions has its own latency.

Every one can fail independently.

Traditional application logs flatten all of this into an unreadable wall of text.

You can't tell whether the agent was:

That distinction matters.

If latency comes from the LLM generating thousands of reasoning tokens, the solution is prompt optimization.

If latency comes from a hanging shell command, the solution is a timeout or sandbox fix.

Without separating those two, you're simply guessing.

AXRAY instruments every agent turn using OpenTelemetry, following the official GenAI Semantic Conventions instead of inventing our own telemetry schema.

Examples include:

gen_ai.request.model

gen_ai.usage.input_tokens

gen_ai.usage.output_tokens

Every span is tagged with a simple phase:

llm

tool

From that we calculate two metrics for every agent turn.

How long the LLM spent thinking, reasoning, and generating tokens.

How long Docker actually spent executing commands.

Those two numbers unlock almost everything.

We also compute an overall execution efficiency score:

const efficiencyScore = Math.max(
  45,
  Math.min(98, 100 - (0.35 * brainPercent + 0.10 * envPercent))
);

The first time I watched a real execution session, I noticed something surprising.

Almost 78% of the latency was inside the LLM.

Our Docker sandbox wasn't slow.

Our shell commands weren't slow.

The context window was simply too large.

That wasn't speculation.

It came directly from a SigNoz trace query against:

signoz_traces.signoz_index_v3

SigNoz ended up powering three completely different layers of AXRAY.

Every LLM request and every tool invocation exports spans through OTLP (:4318

).

Once we mapped our attributes onto the official GenAI semantic conventions, everything started fitting naturally into the existing observability ecosystem.

No custom telemetry format required.

We wanted sub-turn latency breakdowns that standard dashboards don't expose directly.

Because SigNoz stores traces inside ClickHouse, we could run custom SQL like this:

SELECT
    attributes_string['tool.name'] AS toolName,
    avg(durationNano) AS avgDurationNano,
    count() AS executionCount
FROM signoz_traces.signoz_index_v3
WHERE name = 'tool.call'
AND attributes_string['axray.session.id'] = 'sess_42'
GROUP BY toolName
ORDER BY avgDurationNano DESC;

That query instantly showed which tools consumed the most execution time across an entire session.

One feature we really wanted was live alert visibility inside AXRAY itself.

Instead of rebuilding an alerting system, we connected directly to SigNoz's MCP server.

Calling:

signoz_list_alerts

through StreamableHTTPClientTransport

gave us structured JSON containing active alert rules.

This meant:

could appear directly inside AXRAY's UI without duplicating any of SigNoz's alerting logic.

Here's the part I wish someone had warned me about.

Most tutorials still describe the classic:

installation flow.

That isn't the recommended deployment anymore.

SigNoz has moved to Foundry, driven by an extremely small YAML manifest.

apiVersion: v1alpha1
kind: Installation

metadata:
  name: signoz

spec:
  deployment:
    flavor: compose
    mode: docker

  mcp:
    spec:
      enabled: true

Deployment becomes a single command:

foundryctl cast -f casting.yaml

Foundry:

It's actually simpler than the old approach.

I just lost an afternoon following outdated tutorials before discovering it.

The second bug was much sneakier.

I wrote a script that automatically imported dashboards and alert rules into SigNoz's Postgres metadata database.

Everything worked perfectly.

On my machine.

Why?

Because I had accidentally hardcoded my own:

org_id

user_id

Every fresh SigNoz installation generates completely different UUIDs.

That meant my setup script silently failed on a clean installation.

The fix was querying them dynamically.

function getOrgAndUser(container) {
  const orgId = runSql(
    container,
    "SELECT id FROM organizations LIMIT 1;"
  ).stdout.trim();

  const userId = runSql(
    container,
    "SELECT id FROM users LIMIT 1;"
  ).stdout.trim();

  return { orgId, userId };
}

Tiny change.

Huge difference.

It's exactly the kind of bug that only appears when someone else runs your project.

AXRAY started with one simple idea:

"Let's add some logging to our AI agent."

It ended up becoming something much bigger.

A strong argument that AI agents should be treated exactly like any production backend:

Using SigNoz's OpenTelemetry-native architecture meant we didn't have to invent our own telemetry format, and that decision paid off far more than we expected.

If you're building AI agents that combine LLM reasoning with real system execution, the very first metric I'd instrument is:

Time-in-Brain vs Time-in-Environment

It's inexpensive to add.

And it immediately answers the only question that matters when an agent feels slow:

Was it thinking… or was it stuck?

WeMakeDevs × SigNozAgents of SigNoz Hackathon

If you found this interesting, I'd love your feedback!

*Thanks for reading! *

── more in #ai-agents 4 stories · sorted by recency
── more on @signoz 3 stories trending now
sponsored brought to you by zahid.host 4,200+ EU-deployed projects
reading about agents? ship yours in a single git push.

Run your AI side-project on zahid.host

EU-based hosting, git-push deploys, automatic HTTPS, no cold starts. Free tier with a custom domain — perfect for shipping the agent you just read about.

$git push zahid main
Live at https://your-agent.zahid.host
Get free account → Pricing
from €0/mo · no card required
LIVE [news/we-built-a-flight-re…] indexed:0 read:4min 2026-07-26 ·