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 SpartanLabsXyz/simmer-sdk --skill polymarket-market-makergit clone --depth 1 https://github.com/SpartanLabsXyz/simmer-sdkWrote 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/spartanlabsxyz/simmer-sdk/polymarket-market-maker)<a href="https://agentmods.dev/skills/spartanlabsxyz/simmer-sdk/polymarket-market-maker"><img src="https://agentmods.dev/badge/skills/spartanlabsxyz/simmer-sdk/polymarket-market-maker/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/spartanlabsxyz/simmer-sdk/polymarket-market-maker"><img src="https://agentmods.dev/badge/skills/spartanlabsxyz/simmer-sdk/polymarket-market-maker.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00000 | $0.01970 |
| Opus 5 | $0.00000 | $0.00985 |
| Sonnet 5 | $0.00000 | $0.00394 |
| Haiku 4.5 | $0.00000 | $0.00197 |
Grade A, and why
polymarket-market-maker 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 12d 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 — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Polymarket Market Maker
Post two-sided GTC limit orders (bid + ask) on Polymarket CLOB to earn the bid-ask spread as a liquidity provider. This is a developer-only SDK primitive — not a retail "set and forget" skill. You will need to monitor inventory and tune spread/skew parameters to your specific markets.
Why this matters. Akey, Grégoire, Harvie & Martineau (2026) studied 1.4M Polymarket users and $20B in volume. Their headline finding: moving from pure taker to pure market-maker reduces the probability of losing money by 35.9 percentage points — more than 10× larger than any other behavioral predictor (overtrading: 5pp, category concentration: 13.6pp, extreme-price trading: 3pp). This is the single highest-edge behavior on Polymarket.
How it works
Each run (cron or manual):
For each configured market:
1. Fetch current mid price (external_price_yes)
2. Compute bid/ask:
bid = mid - spread/2 (round to 0.01 tick)
ask = mid + spread/2 (round to 0.01 tick)
3. Check inventory: if net_YES_skew > max_skew → pause bidding
if net_NO_skew > max_skew → pause asking
4. Check drift: if existing order price differs from new quote by > drift_threshold
→ cancel and repost
5. Post GTC orders:
BID: client.trade("yes", amount=Q, price=bid, order_type="GTC")
ASK: client.trade("no", amount=Q, price=1-ask, order_type="GTC")
^ Synthetic sell: post NO buy at 1-ask_price instead of YES sell
→ earns maker rebates instead of paying taker fees on exits
6. Log fee-equivalent volume for rebate estimation
Quote structure (synthetic sell on asks)
Polymarket YES and NO tokens are complementary (YES + NO = $1). Instead of posting a sell order on YES (which pays taker fees), this skill posts a buy order on NO at the complementary price:
| Intent | Order posted | Price |
|---|---|---|
| Buy YES | BUY YES GTC | mid - spread/2 |
| Sell YES (ask) | BUY NO GTC | 1 - (mid + spread/2) |
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 12d ago First seen · 167 lines · 0 tokens per session scan A f4a168e345d8
polymarket-market-maker is a skill published in the GitHub repository SpartanLabsXyz/simmer-sdk (48 stars, last pushed today), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 1,970 tokens. 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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