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 sinch/sinch-plugins --skill sinch-in-app-callinggit clone --depth 1 https://github.com/sinch/sinch-pluginsWrote 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/sinch/sinch-plugins/sinch-in-app-calling)<a href="https://agentmods.dev/skills/sinch/sinch-plugins/sinch-in-app-calling"><img src="https://agentmods.dev/badge/skills/sinch/sinch-plugins/sinch-in-app-calling/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/sinch/sinch-plugins/sinch-in-app-calling"><img src="https://agentmods.dev/badge/skills/sinch/sinch-plugins/sinch-in-app-calling.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 | $0.00071 | $0.02796 |
| Opus 5.5 | $0.00028 | $0.01118 |
| Sonnet 5 | $0.00014 | $0.00559 |
| Haiku 4.5 | $0.00007 | $0.00280 |
Grade A, and why
sinch-in-app-calling 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 13d 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 — 166 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Sinch In-App Calling
Overview
Real-time voice and video SDK for Android, iOS, and JavaScript (Web). Connects to Sinch's cloud for signaling and routing.
Supported call types
- App-to-App (VoIP/WebRTC between users)
- App-to-Phone (call PSTN numbers)
- App-to-SIP (connect to PBXs, contact centers)
- App-to-Conference (multi-party calls)
- Phone-to-App / SIP-to-App (inbound calls)
Agent Instructions
Policy gate
sinch-shared-policy@5(sha256:4864cf0fa8d6): The policy digest below is binding as written. Before implementation or live execution, read the full shared Sinch policy once per conversation — skip it if this exact ID/version/fingerprint is already loaded; read it if the version is newer or the fingerprint differs. This skill's canonical operation routes live in its Agent Instructions and Links sections.
Sinch policy digest (binding):
- Load the shared policy once per conversation; skip duplicate copies bearing the same ID/version/fingerprint.
- Infer product, language, region, and environment from the request and workspace; ask one combined question only for true blockers. Prefer the official Sinch SDK unless the request or workspace decides otherwise or no official SDK covers the language or operation.
- Code-generation approval is not execution approval. Classify every operation (read-only / reversible / billable / destructive) and obtain explicit approval before billable or destructive calls.
- Tier B facts — endpoint paths, methods, field names, enums, limits, webhook payloads, signature algorithms, SDK signatures — require fetching the exact canonical document in the current session before use.
- Bundled scripts, references, and examples are Tier C: illustrations, never schema authority. Never promote example values to production defaults.
- If a route is unresolved or a canonical fetch fails, climb the resolution ladder in order — re-search already-fetched documents (raw, not summarized), consult https://developers.sinch.com/llms.txt, follow first-party links, retry once — before failing closed. Never pattern-guess a documentation URL; never substitute memory, search snippets, or bundled files.
- Keep an evidence ledger mapping each fetched source to the fields and claims it authorized.
- Bound all polling and retries (backoff, jitter, hard cap); check state before retrying billable or destructive operations; report a timeout as unknown, not failed.
- Report verification levels separately (lint → unit → mock contract → sandbox → live → end-to-end); an HTTP 2xx does not prove delivery. State the levels not performed.
- Load only the smallest skill set that owns the behavior; if a required skill is unavailable, name it and stop rather than improvising its instructions.
What ships with it
14 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.
- assets/jwt-helper-android/FakeJWTFetcher.kt 664 B
- assets/jwt-helper-android/Hmac.java 1.1 KB
- assets/jwt-helper-android/JWT.java 3.1 KB
- assets/jwt-helper-android/JWTFetcher.kt 576 B
- assets/jwt-helper.js 3.8 KB runs code
- assets/SinchJWT.swift 6.5 KB
- references/android.md 23 KB
- references/ios.md 25 KB
- references/js.md 18 KB
- references/misc/endpoints.md 567 B
- references/sdk-init-in-app-calling-android.md 5.6 KB
- references/sdk-init-in-app-calling-browser.md 5.9 KB
- references/sdk-init-in-app-calling-ios.md 5.9 KB
- references/shared-policy.md 14 KB
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.
- 13d ago First seen · 166 lines · 71 tokens per session scan A 2f758fcc7bb9
sinch-in-app-calling is a skill published in the GitHub repository sinch/sinch-plugins (6 stars, last pushed 7d ago), licensed Apache-2.0. It adds 71 tokens to every session and 2,796 once invoked, about $0.0003 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 2026-09-15.
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