Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add Canner/wren-engine --skill wren-usagegit clone --depth 1 https://github.com/Canner/wren-engineWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/canner/wren-engine/wren-usage)<a href="https://agentmods.dev/skills/canner/wren-engine/wren-usage"><img src="https://agentmods.dev/badge/skills/canner/wren-engine/wren-usage/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/canner/wren-engine/wren-usage"><img src="https://agentmods.dev/badge/skills/canner/wren-engine/wren-usage.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00126 | $0.01581 |
| Opus 5.5 | $0.00050 | $0.00632 |
| Sonnet 5.5 | $0.00025 | $0.00316 |
| Haiku 4.5 | $0.00013 | $0.00158 |
Grade A, and why
wren-usage scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 169 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Wren Engine — Usage Guide
Version check
Silently fetch https://raw.githubusercontent.com/Canner/wren-engine/main/skills/versions.json.
Compare the wren-usage key with this skill's version (from the frontmatter above).
If the remote version is newer, notify the user before proceeding:
A newer version of the wren-usage skill is available. Update with:
npx skills add Canner/wren-engine --skill wren-usage --agent claude-code
Then continue with the workflow below regardless of update status.
This skill is your day-to-day reference for working with Wren Engine. It delegates to focused sub-skills for each task.
Step 0 — Install dependent skills (first time only)
Check whether the required skills are already installed in ~/.claude/skills/. If any are missing, tell the user to run:
# Option A — npx skills (works with Claude Code, Cursor, and 30+ agents)
npx skills add Canner/wren-engine --skill '*' --agent claude-code
# Option B — Clawhub (if installed via clawhub)
clawhub install wren-usage
This installs wren-usage and its dependent skills (wren-connection-info, wren-generate-mdl, wren-project, wren-sql, wren-mcp-setup, wren-http-api) into ~/.claude/skills/.
After installation, the user must start a new session for the new skills to be loaded.
If the user only wants the MCP server set up (no Docker yet), use
/wren-quickstartfor a guided end-to-end walkthrough instead.
What do you want to do?
Identify the user's intent and delegate to the appropriate skill:
| Task | Skill |
|---|---|
| Write or debug a SQL query | @wren-sql |
| Connect to a new database / change credentials | @wren-connection-info |
| Generate MDL from an existing database | @wren-generate-mdl |
| Save MDL to YAML files (version control) | @wren-project |
Load a saved YAML project / rebuild target/mdl.json |
@wren-project |
| Add a new model or column to the MDL | @wren-project |
| Start, reset, or reconfigure the MCP server | @wren-mcp-setup |
| Call Wren tools via HTTP JSON-RPC (no MCP SDK) | @wren-http-api |
| First-time setup from scratch | @wren-quickstart |
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 169 lines · 126 tokens per session scan A 6117d6c9e798
wren-usage is a skill published in the GitHub repository Canner/wren-engine (660 stars, last pushed 5mo ago), licensed Apache-2.0. It adds 126 tokens to every session and 1,581 once invoked, about $0.0005 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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