A field guide for developersVOL. 06

Give every agent step an explicit boundary.

Define authorization, state, and result contracts before connecting real tools.

Explicit costs · Repeatable setup · Checkable evidence

PRACTICAL TOOL / 01

First-request checklist

Turn a working request into a repeatable check.

POST /v1/chat/completions

{
  "model": "YOUR_MODEL_ID",
  "messages": [
    { "role": "user", "content": "Hello" }
  ]
}

Confirm the current model ID and API protocolMake a minimal request with a separate test keyCheck stream completion, usage and the billCheck timeout, rate-limit and data-handling boundaries

BEFORE YOU CHOOSE

Ask better questions before you connect.

01 / COST

Separate input, output and cache.

Compare the same workload using the same units.

02 / CAPABILITY

A model label is not a test result.

Validate images, tools and context separately.

03 / SERVICE

Read the sample, not just the percentage.

Keep the observation window and sample count visible.

INDEX / 03

Field notes

Provider-neutral agent engineering focused on verifiable workflows and side-effect controls. Validate actual model and tool behavior against current requirements.

Authorization design

Create reviewable approval gates before agent tool execution

Separate a plan, concrete arguments, and execution permission so vague consent cannot expand silently.

6 min read

Recovery engineering

Resume interrupted agent tasks from reliable state

Persist step state and side-effect evidence so recovery does not replay the whole workflow.

6 min read

Tool contracts

Define explicit data contracts for agent tool results

Validate structure, bound content, and keep returned data separate from control instructions.

6 min read

NEXT / NEXOTOKEN

Take the checklist into your workflow.

Check current models and pricing on NexoToken, then validate a small task before expanding.

Model directory Pricing notes Public status