Xberg is a document-intelligence engine that reads files, URLs, archives, and source trees and extracts text, metadata, images, tables, and structured data, with additional code-language understanding. Developers use it through language bindings, a command-line tool, REST API, or MCP server, and the catalogue entries support those integrations.
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 xberg-io/xberg --skill feature-flag-conventionsgit clone --depth 1 https://github.com/xberg-io/xbergWrote 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/xberg-io/xberg/feature-flag-conventions)<a href="https://agentmods.dev/skills/xberg-io/xberg/feature-flag-conventions"><img src="https://agentmods.dev/badge/skills/xberg-io/xberg/feature-flag-conventions/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/xberg-io/xberg/feature-flag-conventions"><img src="https://agentmods.dev/badge/skills/xberg-io/xberg/feature-flag-conventions.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 | $0.00035 | $0.03206 |
| Opus 5.5 | $0.00014 | $0.01282 |
| Sonnet 5.5 | $0.00007 | $0.00641 |
| Haiku 4.5 | $0.00003 | $0.00321 |
Grade A, and why
feature-flag-conventions 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 yesterday.
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 — 150 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Feature-flag conventions
Shared concerns use the same flag name with the same semantics in every library. A consumer that learns otel or mcp once should get identical behavior across every library and its bindings. Repo-specific flags stay local — this contract governs only shared concerns.
Standard flags
| Flag | Meaning | Default | Notes |
|---|---|---|---|
(none) tracing |
Structured tracing is always-on, never a feature. | — | tracing is a non-optional dependency. Do not gate span emission. Un-gate any legacy optional tracing feature. |
otel |
Opt-in OpenTelemetry / OTLP export layer, on top of always-on tracing. | off | Pulls tracing-opentelemetry + the opentelemetry* stack. This is the only observability feature. Reconcile any always-on OTLP deps behind it. |
mcp |
Embedded Model Context Protocol server (stdio transport). | off | |
mcp-http |
MCP Streamable HTTP transport; implies mcp. |
off | mcp-http = ["mcp", ...]. |
mimalloc |
Select the mimalloc global allocator. | off | Mutually exclusive with jemalloc; see the allocator rule below. |
jemalloc |
Select the jemalloc global allocator. | off | Mutually exclusive with mimalloc. |
cuda / metal / mkl / accelerate |
Device / BLAS acceleration backends where a crate exposes them. | off | Same names wherever acceleration is offered. |
Rules
- Names are the contract. Never invent a synonym for a shared concern (
opentelemetry,observability,otlpfor what isotel;model-context-protocolformcp). Rename divergent flags to match. - Semantics travel with the name.
otelmust mean the OTLP export layer everywhere, not "enable tracing" (tracing is always-on) and not a metrics-only subset. - Always-on tracing, opt-in export. Do not force the
opentelemetrydependency tree on library consumers — keep it behindotelso a plain dependency stays lean. - Implication edges are fixed:
mcp-http⇒mcp;otel⇒ (always-on) tracing. - Mutually-exclusive allocators carry a both-enabled
compile_error!guard by default. Exception: a crate that must build with--all-features(a coverage gate,cargo doc --all-features) resolves by precedence instead,jemallocwinning viacfg(all(feature = "mimalloc", not(feature = "jemalloc"))), and states why in a~keepcomment at the#[global_allocator]. - Adding a shared flag to a new library? Copy the name, default, and implication edges from this table rather than redefining them. Coordinate a change to this contract across all libraries before landing it — no repo diverges unilaterally.
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.
- yesterday First seen · 150 lines · 35 tokens per session scan A 16fb7e968be8
feature-flag-conventions is a skill published in the GitHub repository xberg-io/xberg (9,458 stars, last pushed today), licensed MIT. It adds 35 tokens to every session and 3,206 once invoked, about $0.0001 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 2026-10-28.
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