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 skills/elbwalker/walkeros/walkeros-understanding-mappingnpx skills add elbwalker/walkerOS --skill walkeros-understanding-mappinggit clone --depth 1 https://github.com/elbwalker/walkerOSWrote 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/elbwalker/walkeros/walkeros-understanding-mapping)<a href="https://agentmods.dev/skills/elbwalker/walkeros/walkeros-understanding-mapping"><img src="https://agentmods.dev/badge/skills/elbwalker/walkeros/walkeros-understanding-mapping.svg" alt="Measured on agentmods" 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 | $0.00000 | $0.04217 |
| Opus 5 | $0.00000 | $0.02108 |
| Sonnet 5 | $0.00000 | $0.00843 |
| Haiku 4.5 | $0.00000 | $0.00422 |
Grade A, and why
walkeros-understanding-mapping 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 4d 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 — 578 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Understanding walkerOS Mapping
Overview
Mapping transforms data at multiple points in the walkerOS flow:
- Source → Collector: Transform raw input (HTTP requests, dataLayer pushes) into walkerOS events
- Collector → Destination: Transform walkerOS events into vendor-specific formats
Core principle: Mapping is the universal transformation layer. Same strategies work everywhere in the flow.
Core Functions
See packages/core/src/mapping.ts for implementation.
| Function | Purpose |
|---|---|
getMappingEvent(event, rules) |
Find mapping rule for an event |
getMappingValue(value, data, options) |
Transform a value using mapping config |
processEventMapping(event, config, collector) |
Unified processing for sources/destinations |
processEventMapping Flow
1. Apply config.policy (modifies event)
2. Find matching rule via getMappingEvent()
3. Apply rule.policy (modifies event)
4. Transform config.data (global)
5. Check rule.ignore (short-circuits if true)
5b. Read rule.silent (informational - destination honors it)
6. Override event.name if rule.name
7. Transform rule.data (event-specific)
Configuration Hierarchy
Mapping.Config (Top Level)
interface Config {
consent?: Consent; // Required consent for ALL events
data?: Value; // Global data transformation
include?: string[]; // Event sections to flatten into context.data
policy?: Policy; // Pre-processing for ALL events
mapping?: Rules; // Event-specific rules
}
Mapping.Config.include
include lists event sections to flatten into the destination's
PushContext.data before the rule runs. Sections are top-level keys of the
event (globals, user, consent, data, context, nested, source,
custom). The runtime helper flattenIncludeSections (in
packages/core/src/include.ts) handles the merge.
What ships with it
3 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.
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.
- 4d ago First seen · 578 lines · 0 tokens per session scan A 8d25f484e3e4
walkeros-understanding-mapping is a skill published in the GitHub repository elbwalker/walkerOS (343 stars, last pushed yesterday), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 4,217 tokens. 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 2026-08-30.
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