Agent skill

Refresh JSON Data

by rajbos in rajbos/ai-engineering-fluency

Refresh token estimator and model pricing JSON files with latest data from AI model providers

MITAuto-check passedDevelopment

Install Refresh JSON Data

skills CLI
$ npx skills add rajbos/ai-engineering-fluency --skill refresh-json-data -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI
$ gh skill install rajbos/ai-engineering-fluency refresh-json-data --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy
$ git clone --depth 1 https://github.com/rajbos/ai-engineering-fluency.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/refresh-json-data .claude/skills/refresh-json-data && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Facts

Skill name
refresh-json-data
GitHub stars
115
Token cost
~1.4k tokens
SKILL.md length
545 words
Files
1
Skills in repo
22
Repo updated
First seen
Licence
MIT

At a glance

Refresh token estimator and model pricing JSON files with latest data from AI model providers

  • Works in 3 steps: Update tokenEstimators.json → Update modelPricing.json → Build and Test
  • Development work in your project
  • SKILL.md covers Overview, When to Use This Skill, Prerequisites and Step 1: Update…, plus 6 more sections
  • Calls npm and git; reaches json-schema.org

What it does

Refresh JSON Data is an agent skill from rajbos/ai-engineering-fluency. Refresh token estimator and model pricing JSON files with latest data from AI model providers

Its SKILL.md is about 1.4k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Development. The repository describes itself as: Extension that shows information about the estimated token usage and more of AI in editors/CLI's. The licence is MIT.

When your agent uses it

  • Development work in your project

Example prompts

  • “/refresh-json-data”

Requirements

  • Node.js

Workflow steps

3 steps, taken from the step headings in SKILL.md.

  1. Update tokenEstimators.json
  2. Update modelPricing.json
  3. Build and Test

What it can do on your machine

Read from SKILL.md and the folder at commit 6933e2a. It shows what the files ask for, not the result of running them.

  • Tool permissions

    Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.

    From allowed-tools in the SKILL.md frontmatter.

  • Runs code

    Shell commands in SKILL.md call:

    • npm
    • git

    From the folder's file list and the shell code blocks in SKILL.md.

  • Network

    Hosts in commands or code, which the agent is likely to contact:

    • json-schema.org

    Also links to:

    • openrouter.ai
    • docs.github.com
    • openai.com
    • anthropic.com
    • platform.claude.com
    • ai.google.dev
    • x.ai
    • pricepertoken.com
    • ai-pricing.info
    • code.visualstudio.com

    From URLs in SKILL.md, links to its own repository left out.

  • Credentials

    Names no API keys, tokens, secrets or passwords.

    From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

Refresh JSON Data loads about 1.4k tokens when it runs. Until then it costs about 28 tokens; SKILL.md has 545 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it
~28
When it runs · the whole SKILL.md, loaded when a task matches
~1.4k

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from rajbos/ai-engineering-fluency at commit 6933e2a, republished under its MIT licence (© rajbos). 545 words, ~1,447 tokens.

Download SKILL.mdSave it as .claude/skills/refresh-json-data/SKILL.md (or your agent's skills folder).
name
refresh-json-data
description
Refresh token estimator and model pricing JSON files with latest data from AI model providers

Refresh JSON Data Skill

This skill helps you update the token estimation ratios and model pricing data in the AI Engineering Fluency extension.

Overview

The extension uses two JSON data files that need periodic updates:

  1. tokenEstimators.json - Character-to-token ratio estimators for AI models
  2. modelPricing.json - Pricing information per million tokens for various AI models

These files are located in src/ directory and are bundled into the extension at build time.

When to Use This Skill

Use this skill when you need to:

  • Add support for new AI models
  • Update token estimation ratios based on new benchmarks
  • Refresh pricing information from provider APIs
  • Keep model data current with latest releases

Prerequisites

Before updating these files, ensure you have:

  • Access to official pricing documentation from AI providers
  • Token estimation benchmarks or documentation
  • The repository cloned locally
  • Node.js and npm installed

Step 1: Update tokenEstimators.json

Location

src/tokenEstimators.json

Structure
json
{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "description": "Character-to-token ratio estimators for different AI models.",
  "estimators": {
    "model-name": 0.25
  }
}
Update Process
  1. Research token ratios for new or updated models:

    • Look at the existing ratios for that provider's other models in tokenEstimators.json and match the pattern; verify with an actual tokenizer if unsure
  2. Add or update entries in the estimators object:

    json
    "new-model-name": 0.25
  3. Validation:

    • Ensure JSON syntax is valid
    • Keep ratio values between 0.20 and 0.30
    • Use consistent formatting

Step 2: Update modelPricing.json

Location

src/modelPricing.json

Structure
json
{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "description": "Model pricing data - costs per million tokens",
  "metadata": {
    "lastUpdated": "YYYY-MM-DD",
    "sources": [
      {
        "name": "Provider Name",
        "url": "https://pricing-url",
        "retrievedDate": "YYYY-MM-DD"
      }
    ],
    "disclaimer": "..."
  },
  "pricing": {
    "model-name": {
      "inputCostPerMillion": 1.25,
      "outputCostPerMillion": 10.0,
      "category": "Model category"
    }
  }
}
Update Process
  1. Check official pricing pages:

  2. Update pricing entries in the pricing object:

    json
    "model-name": {
      "inputCostPerMillion": 1.25,
      "outputCostPerMillion": 10.0,
      "category": "Provider models"
    }
  3. Update metadata:

    • Set metadata.lastUpdated to current date (YYYY-MM-DD format)
    • Add or update source URLs and retrieval dates
    • Keep the disclaimer intact
  4. Pricing guidelines:

    • Costs are per million tokens
    • Input costs are typically lower than output costs
    • Group models by category (e.g., "GPT-4 models", "Claude models")
    • Verify pricing is in USD
  5. Validation:

    • Ensure JSON syntax is valid
    • Verify pricing values are positive numbers
    • Check that all required fields are present
Show full SKILL.md (198 more words)Show less

Step 3: Build and Test

Validate JSON syntax, run npm run compile && npm run test:node (do not launch VS Code or the Extension Development Host — that is a manual, human-only debugging step; see .github/copilot-instructions.md), review with git diff, then commit/push as usual.

Important Notes

  • Bundled at build time: These JSON files are bundled into the extension during compilation via esbuild.js
  • Rebuild required: Always run npm run compile after changes
  • Pricing disclaimer: GitHub Copilot pricing may differ from direct API usage
  • Estimation nature: Token counts are estimates based on character ratios
  • Documentation: See src/README.md for additional details

Reference Resources

  • VS Code extension development: https://code.visualstudio.com/api
  • Token estimation methodology: Character-to-token ratios based on model tokenizers
  • Cost calculation: Uses 50/50 split between input and output tokens for estimates

Troubleshooting

Extension not loading updated data:

  • Confirm you ran npm run compile
  • Confirm npm run test:node passes
  • Check the build output for errors

Additional Context

The extension reads these files at compile time via:

typescript
import tokenEstimatorsData from './tokenEstimators.json';
import modelPricingData from './modelPricing.json';

The data is then used in the CopilotTokenTracker class:

  • tokenEstimators - Used for token estimation from character counts
  • modelPricing - Used for cost calculations in the details panel

Both files must maintain their structure to ensure the extension compiles and runs correctly.

© rajbos, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file

Files

Just SKILL.md in .claude/skills/refresh-json-data of rajbos/ai-engineering-fluency.

Open the folder on GitHubat commit 6933e2a

Compare with similar skills

Refresh JSON Data next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

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Code Review ChecklistshareAI-lab/learn-claude-code78k5 repos~1.1kAutomated safety check: PassMIT
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Categories

Questions about Refresh JSON Data

What does Refresh JSON Data do?

Refresh token estimator and model pricing JSON files with latest data from AI model providers. Refresh JSON Data is an agent skill from rajbos/ai-engineering-fluency.

When should I use Refresh JSON Data?

Refresh JSON Data fits situations like: development work in your project.

How do I install Refresh JSON Data in Claude Code?

Run `npx skills add rajbos/ai-engineering-fluency --skill refresh-json-data -a claude-code`. Or copy the skill folder (.claude/skills/refresh-json-data in rajbos/ai-engineering-fluency) into .claude/skills/refresh-json-data in your project. Claude Code loads it when a task matches its description.

How do I install Refresh JSON Data in Codex?

Run `npx skills add rajbos/ai-engineering-fluency --skill refresh-json-data -a codex`. Or copy the skill folder (.claude/skills/refresh-json-data in rajbos/ai-engineering-fluency) into .agents/skills/refresh-json-data in your project. Codex loads it when a task matches its description.

Can I use Refresh JSON Data in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add rajbos/ai-engineering-fluency --skill refresh-json-data -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/refresh-json-data, .gemini/skills/refresh-json-data, .github/skills/refresh-json-data and .opencode/skills/refresh-json-data in your project.

What does Refresh JSON Data need to run?

Going by SKILL.md and its folder, Refresh JSON Data needs the command-line tools its instructions call (npm and git). Our summary lists: Node.js.

Does Refresh JSON Data access the network?

SKILL.md names 11 domains. In commands or code: json-schema.org; the agent is likely to contact it when it follows the instructions. As links in the text: openrouter.ai, docs.github.com, openai.com, anthropic.com, platform.claude.com, ai.google.dev, x.ai, pricepertoken.com, ai-pricing.info and code.visualstudio.com. This is read from the text; nothing was executed.

Is Refresh JSON Data safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does Refresh JSON Data use?

Refresh JSON Data is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does Refresh JSON Data use?

About 1.4k tokens (SKILL.md is roughly 5.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to Refresh JSON Data?

Skills that share tags, products or a category with Refresh JSON Data: Finishing a Development Branch (obra/superpowers, 296k stars), Typescript Advanced Types (rolling-scopes/rsschool-app, 10k stars), PR Babysitter (openinterpreter/openinterpreter, 69k stars) and Code Review Checklist (shareAI-lab/learn-claude-code, 78k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains Refresh JSON Data?

rajbos (a GitHub user) maintains it in rajbos/ai-engineering-fluency, which has 115 GitHub stars. The repository holds 22 skills in this directory. The repository was last updated on October 6, 2026.

Source: rajbos/ai-engineering-fluency on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.