Field notes

What we learn while operating the stack.

Engineering notes, product decisions, and practical guidance from the systems behind Everstack.

01Engineering
02Product decisions
03Operations

August 30, 202614 min readOpenTelemetryObservabilityEngineering

OpenTelemetry for LLM Applications: A Practical Guide

How to instrument LLM applications with OpenTelemetry using the GenAI semantic conventions, why gen_ai.system is now gen_ai.provider.name, what belongs on a span, and how to avoid the two mistakes that make traces useless.

August 29, 202610 min readAI GatewayOpen SourceSelf-HostedComparison

Best Open-Source AI Gateways in 2026

Seven open-source AI gateways compared on the fact that decides most adoptions: which capabilities stop working when you self-host without paying. Licences, tier boundaries and prices checked against each project's own repository and pricing page in August 2026.

August 28, 202611 min readObservabilityOpenTelemetrySelf-HostedComparison

Best Self-Hosted LLM Observability Tools in 2026

Six self-hosted LLM observability tools compared on the things that actually decide adoption: the real licence, which features a licence key gates, how many datastores you have to run, and what it costs. Facts checked against each project's own repository and pricing page in August 2026.

August 27, 202610 min readSandboxesSecurityAI AgentsComparison

Best Code Execution Sandboxes for AI Agents in 2026

Six sandbox platforms for running AI-generated code, compared on isolation primitive, whether you can self-host, how concurrency is priced, and one project whose open source repository quietly stopped shipping updates.

August 26, 202611 min readSecuritySandboxesAI AgentsEngineering

How to Safely Run AI-Generated Code

A practical threat model for executing code an LLM wrote: why containers alone are the wrong boundary, what microVMs and gVisor actually buy you, and the network, filesystem and resource controls that matter more than the isolation primitive.

August 24, 20269 min readCostObservabilityMulti-TenancyEngineering

Per-Tenant LLM Cost Tracking That Survives an Audit

Why token counts from provider dashboards cannot be attributed to customers, what to record at request time so cost is reconstructable later, and the three mistakes that make an LLM cost model quietly wrong.

August 23, 20269 min readEvaluationsComparisonSelf-Hosted

Best LLM Evaluation Platforms in 2026

Five evaluation platforms compared on the questions that decide adoption: whether self-hosting is gated by tier, how pricing scales with evaluation volume, and whether evals connect to the system that produced the outputs.

August 22, 20268 min readLiteLLMMigrationAI GatewayEngineering

Migrating from LiteLLM: What Actually Breaks

A practical migration guide from LiteLLM to another self-hosted gateway. What moves with a base URL change, what has to be rewritten, what does not carry over at all, and when you should not migrate.

August 21, 202611 min readSelf-HostedArchitectureOpen Source

How to Build a Fully Self-Hosted AI Stack

The six layers of a production AI stack, which open-source project to use for each, where the licence lines fall, and the integration work between layers that nobody budgets for.

August 17, 20269 min readLLM GatewaySelf-HostedInfrastructureGuide

How to Self-Host an LLM Gateway

A practical walkthrough for running an LLM gateway on your own infrastructure: what self-hosting actually buys you, how to read the licence, and a working Docker Compose deployment with routing, keys, and tracing.

March 12, 20265 min readLaunchSelf-HostedAI Infrastructure

Introducing Everstack: The AI Infrastructure Platform

Today we are launching Everstack in alpha - a self-hosted platform that unifies AI gateway routing, agent orchestration, workflow studios, sandboxed execution, and full-stack observability into a single deployable stack.

Open-source AI infrastructure

Ship the AI stack
you can actually operate.

Start with one model call. Add agents, sandboxes, evaluations, memory, and traces without replacing the foundation underneath them.

Start with $5 credit Self-host Everstack

One-time starter credit per account on Everstack Cloud. Expires 30 days after signup.