Borrowing it
Nothing to install: this file belongs to getpostern/postern. 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/getpostern/postern/main/.claude/skills/new-connector/SKILL.mdgit clone --depth 1 https://github.com/getpostern/posternWrote 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/getpostern/postern/new-connector)<a href="https://agentmods.dev/skills/getpostern/postern/new-connector"><img src="https://agentmods.dev/badge/skills/getpostern/postern/new-connector/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/getpostern/postern/new-connector"><img src="https://agentmods.dev/badge/skills/getpostern/postern/new-connector.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 | $0.00039 | $0.01356 |
| Opus 5.5 | $0.00016 | $0.00542 |
| Sonnet 5.5 | $0.00008 | $0.00271 |
| Haiku 4.5 | $0.00004 | $0.00136 |
Grade A, and why
new-connector 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.
How it starts
The opening of the file, as written. The whole thing — 52 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Adding or changing a connector
The contract is already code — read it, don't re-derive it
src/sdk/contract.ts → CONTRACT_OBLIGATIONS is the machine-readable contract (H1–H8 + H-types enforced by the runner; S1–S12 convention, made mechanical by the harness). src/sdk/README.md is its prose mirror and carries the 4-step "how to add a connector (and prove it conforms)" recipe — follow that, and read the per-member JSDoc in src/connectors/types.ts rather than any summary of it.
The harness is describeConformance from src/sdk/index.js: a contract layer (pure, no DB, no transport, drives your ConformanceFixtures) plus an optional integration layer that drives the real syncConnection through your own mock to prove H6/H7/H8/S1/S2. src/connectors/icloud-calendar.conformance.ts + .conformance.test.ts is the smallest complete pair to model on; the Home Assistant exemption (a push connector that owns its own writes) is documented in the README.
⚠️ docs/agent-authored-connectors.html:151 renders a Connector interface with three members (sync/normalize/strongKeys). That is positioning material for readers, NOT the contract. The real interface is src/connectors/types.ts:131 and has twelve members. Build from the HTML and you build the wrong thing.
The golden-fixture rule — the one that has actually bitten
Faked-transport tests cannot catch a real provider's response shape. They assert that your code handles the shape your fake emits, which is the shape your code already expects. That is a tautology, and it shipped a connector that stored zero rows.
The iCloud DAV connector passed its whole suite green and then stored 0 rows against real iCloud: dav-core read bodies off the on-the-wire kebab key calendar-data, but tsdav camelCases response elements to calendarData and CDATA-wraps the body as {_cdata: "..."}. Only the live smoke caught it. The fix and the warning now live at src/connectors/dav-core.ts:255.
So, for any new source:
What ships with it
1 file 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.
- 2mo ago First seen · 52 lines · 39 tokens per session scan A 6075afe5ecb7
new-connector is a skill published in the GitHub repository getpostern/postern (2 stars, last pushed 2d ago), licensed Apache-2.0. It adds 39 tokens to every session and 1,356 once invoked, about $0.0002 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 2026-08-31.
new-connector compared with skills from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| new-connectorgetpostern/postern | Skill | 2 | 2d ago | Apache-2.0 | A | 39 | Claude Code |
| api-mirrorcyanheads/obsidian-mcp-server | Skill | 702 | 6d ago | Apache-2.0 | A | 68 | Claude Code |
| supabase-sdk-patternsCoWork-OS/CoWork-OS | Skill | 534 | yesterday | MIT | A | 20 | Claude Code, Codex |
| cmdb-patternsserac-labs/serac | Skill | 77 | 17d ago | Apache-2.0 | A | 43 | Claude Code |
| gliderecord-patternsserac-labs/serac | Skill | 77 | 17d ago | Apache-2.0 | A | 46 | Claude Code |
| odoo-mcprachmataditiya/odoo-rust-mcp | Skill | 16 | 12d ago | MIT | A | 100 | Claude Code, Codex |
| run402kychee-com/run402 | Skill | 24 | 2d ago | MIT | B | 51 | Claude Code, Codex |