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 agentmods add instructions/paritytech/playground-cli/claude-mdgit clone --depth 1 https://github.com/paritytech/playground-cliWhat 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 | $0.17912 | $0.17912 |
| Opus 5 | $0.08956 | $0.08956 |
| Sonnet 5 | $0.03582 | $0.03582 |
| Haiku 4.5 | $0.01791 | $0.01791 |
Grade A, and why
playground-cli CLAUDE.md 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 2d 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 — 134 lines — stays where its author put it; the contents beside it link to each section on GitHub.
CLAUDE.md
Refer to the Contributing and Architecture Highlights sections of README.md for development workflows, the release process, and repo conventions.
Verification before committing
Before claiming a task complete, opening a PR, or merging, run all four. The first three are enforced by CI; pnpm test also catches regressions:
pnpm format:check
pnpm lint:license
pnpm typecheck
pnpm test
pnpm build compiles with bun, which STRIPS types without checking them — it is NOT a type signal. The tsc baseline was burned to zero in June 2026 and pnpm typecheck (tsc --noEmit) now runs as a CI job, so any new type error fails the build — keep it at zero. The cdm-builder version skew is bridged through THREE cast seams: asCloudStorageApi in src/utils/allowances/bulletin.ts (the TypedApi<Paseo_bulletin> vs BulletinTypedApi codegen skew — two codegens of the same chain), plus asCdmAssetHubApi/asCdmAssetHubDescriptor and asCdmRegistryContract in src/commands/contract.ts. The asset-hub seams bridge the paseo-asset-hub DotnsGateway/descriptor shape drift between cdm-builder's pinned @parity/product-sdk-descriptors and our root's (the contract pipeline never touches DotnsGateway, so the cast is runtime-safe). asCdmRegistryContract was added when our root @parity/product-sdk-contracts reached 0.9.x: Contract.tx() now resolves a Result<TxResult, …>, nominally unassignable to cdm-builder's older RegistryContract param — but the install-time registry is query-only (no signer wired in), so .tx() is never invoked through it and the cast is runtime-safe. At [email protected] the pinned product-sdk moved up to [email protected] / [email protected] while our root is contracts@^0.9.2 / descriptors@^0.8.0 — so the .tx() Result shape realigns (making asCdmRegistryContract likely redundant) while a descriptors minor gap (0.7 vs 0.8) remains. Before deleting any seam, remove it and run pnpm typecheck. If lint:license flags a file you authored, run ./scripts/check-license-headers.sh --fix to prepend the standard Parity Apache-2.0 header (SPDX-License-Identifier: Apache-2.0 + Copyright (C) Parity Technologies (UK) Ltd., both lines required). The check script keeps shebangs on line 1 and places the header below them.
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.
- 2d ago First seen · 134 lines · 17,912 tokens per session scan A 82e9dd68add4
playground-cli CLAUDE.md is an instructions file published in the GitHub repository paritytech/playground-cli (5 stars, last pushed 12d ago), licensed Apache-2.0. It adds 17,912 tokens to every session, about $0.0896 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 2026-08-31.
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