check-cross-venue-edge

check-cross-venue-edge is a skill for Claude Code from hmesutozsoy/oddsrail. It costs 44 tokens per session (337 once invoked), scanned A, original, MIT.

A procedure for checking whether a price difference between Polymarket and Kalshi reflects a real trading opportunity or different settlement rules.

In plain words
What is it for?
It is for comparing market wording, settlement criteria, order-book costs, and slippage before sizing a cross-market trade.
Why use it?
It helps avoid treating mismatched markets or trading costs as a genuine edge.

Skill for Claude Code

Written for Claude Code: $ARGUMENTS substitution.

Part of the oddsrail plugin — 4 skills, 1 MCP server shipped together

Good fit It is for comparing market wording, settlement criteria, order-book costs, and slippage before sizing a cross-market trade.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/hmesutozsoy/oddsrail/check-cross-venue-edge
Install

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.

Any agent
npx skills add hmesutozsoy/oddsrail --skill check-cross-venue-edge
Clone the repo
git clone --depth 1 https://github.com/hmesutozsoy/oddsrail

Made for: Claude Code.

Or install oddsrail, the plugin that ships this one along with the rest of its 4 skills, 1 MCP server.

Wrote 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.

agentmods badge for check-cross-venue-edge

README.md
[![agentmods](https://agentmods.dev/badge/skills/hmesutozsoy/oddsrail/check-cross-venue-edge/github.svg)](https://agentmods.dev/skills/hmesutozsoy/oddsrail/check-cross-venue-edge)
Your own site
<a href="https://agentmods.dev/skills/hmesutozsoy/oddsrail/check-cross-venue-edge"><img src="https://agentmods.dev/badge/skills/hmesutozsoy/oddsrail/check-cross-venue-edge/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.

agentmods 80×15 button for check-cross-venue-edge

Your own site · 80×15
<a href="https://agentmods.dev/skills/hmesutozsoy/oddsrail/check-cross-venue-edge"><img src="https://agentmods.dev/badge/skills/hmesutozsoy/oddsrail/check-cross-venue-edge.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 337 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00044 $0.00337
Opus 5 $0.00022 $0.00169
Sonnet 5 $0.00009 $0.00067
Haiku 4.5 $0.00004 $0.00034

Measured 8d ago against content hash 879c1a045b45, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

check-cross-venue-edge 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 8d 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.

skills/check-cross-venue-edge/SKILL.md · 26 lines

What it actually says

check cross venue edge

Use the tools of the oddsrail MCP server (install: pip install oddsrail, then claude mcp add --transport stdio oddsrail -- oddsrail, or enable the oddsrail plugin). Prices are implied probabilities in (0,1). Trading tools are dry-run unless the operator has set ODDSRAIL_DRY_RUN=0; never assume an order was placed without checking the dry_run field of the result.

Investigate whether '$ARGUMENTS' offers a genuine cross-venue edge.

  1. compare_venues('$ARGUMENTS') — candidates only. It returns nothing for most queries, which is the honest answer, not a failure.
  2. For any candidate: settlement_audit(polymarket_id, kalshi_ticker). A 'block' verdict ends it — the legs do not hedge each other and the price difference is not an edge.
  3. On 'ok' or 'caution': quote_cost on BOTH legs at the size you would actually trade. Cross-venue differences are usually smaller than the combined slippage.
  4. Read resolution_criteria on both sides yourself. Identical wording does not mean identical settlement.
  5. Only then size the trade.

State plainly if the conclusion is 'no edge here' — that is the usual and correct outcome.

Changes

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.

  1. 8d ago First seen · 26 lines · 44 tokens per session scan A 879c1a045b45

Subscribe to this mod's changes

check-cross-venue-edge is a skill published in the GitHub repository hmesutozsoy/oddsrail (0 stars, last pushed today), licensed MIT. It adds 44 tokens to every session and 337 once invoked, about $0.0002 per session on Opus 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 2026-09-04.

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