Borrowing it
Nothing to install: this file belongs to gridaco/nothing. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/gridaco/nothing/main/.agents/skills/sdk-seam/SKILL.mdgit clone --depth 1 https://github.com/gridaco/nothingWrote 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/gridaco/nothing/sdk-seam)<a href="https://agentmods.dev/skills/gridaco/nothing/sdk-seam"><img src="https://agentmods.dev/badge/skills/gridaco/nothing/sdk-seam/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/gridaco/nothing/sdk-seam"><img src="https://agentmods.dev/badge/skills/gridaco/nothing/sdk-seam.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 | $0.00142 | $0.04362 |
| Opus 5.5 | $0.00057 | $0.01745 |
| Sonnet 5.5 | $0.00028 | $0.00872 |
| Haiku 4.5 | $0.00014 | $0.00436 |
Grade A, and why
sdk-seam 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 2mo 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.
This is a copy
100% identical to sdk-seam — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 350 lines — stays where its author put it; the contents beside it link to each section on GitHub.
sdk-seam
Companion to
sdk-design. Read that first; its deciding table and disciplines are the foundation this skill builds on. Wheresdk-designis about a single SDK's surface, this skill is about the seam — the joint between two SDKs (or two sides of one contract) — and what it takes to keep that joint clean when the same author writes both sides.
The failure mode
When you control both sides of a boundary, you produce dirty contracts — simply because you can. A field gets added on the producer side because the consumer needs it; the consumer reaches into the producer's internal shape because no public view exposes the slice; a one-off helper crosses the boundary because "we're going to refactor it later." Six months later the contract is unrecoverable, and the two sides can only be deployed together.
The honest test: if we couldn't shotgun-edit both sides at once, this design wouldn't be possible. That's not a virtue. It's a warning.
If the contract had been an IPC channel, an FFI ABI, a network protocol, or a published-versus-consumed package boundary from the start, the design would have been clean from the beginning, and it would have evolved cleanly. Cross-boundary work inside one repo, one workspace, or one mono-language project doesn't get that discipline for free — you have to manufacture it.
This applies to:
- Two
packages/grida-*packages where one consumes the other. - A package and its host application (a
crates/*crate + a binary that links it; an npm package + a Next.js app). - A Rust crate and its WASM/FFI bindings (where one party can change generated code on the other side at will).
- Two services sharing a wire format you control on both ends.
- Two modules within one package that genuinely should be on opposite sides of a contract (because one is "core logic" and the other is "shell" — see $sdk-design D2).
The exercise
Before editing, restate the work as if you only owned one side.
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.
- 2mo ago First seen · 350 lines · 142 tokens per session scan A 4c9ef6b6605a
sdk-seam is a skill published in the GitHub repository gridaco/nothing (54 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 142 tokens to every session and 4,362 once invoked, about $0.0006 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to sdk-seam, differing in 0 lines, and is treated as a copy.
Other skills, from other repositories
write-pr
Reference standards for writing pull request titles and descriptions in the tldraw repository, plus the pre-flight comment sweep over the diff. Use as supporting guidance when another skill or workflow needs PR content standards, not as the user-facing create/update PR workflow.
pr-walkthrough
Create a narrated video walkthrough of a pull request with code slides and audio narration. Use when asked to create a PR walkthrough, PR video, or walkthrough video.
shepherd-pr
Keep an eye on this PR. Review and resolve pull request comments and fix build failures autonomously. Use when asked to review PR feedback, address reviewer comments, fix CI failures, resolve PR threads, or handle PR maintenance tasks like "review PR comments", "fix the build", "address PR feedback", "clean up PR", or…
pr
Create or update a pull request for the current branch in the tldraw repository. Use when the user invokes pr, asks to create a PR, update an existing PR, push current branch changes for review, or prepare a pull request.
gh-find-prs
Survey open Codewhale PRs and triage each for mergeability and disposition against the real landing branch.
review
Diff-scoped correctness review that reads the codebase around the change — callers, contracts, and invariants — and returns line-anchored findings ranked by severity with confidence, then a merge-risk verdict. Use for reviewing a PR, diff, or named change set. Not for style review, approvals-as-rubber-stamp, or…