What is sidecar-auth-context?

A set of instructions for connecting resolver and access-control plugins to an agent platform. Resolver plugins supply request-specific information, while access checks decide whether protected workflow nodes may be used.

Use it when implementing plugin contracts, building request execution context, filling prompt variables, or hiding protected nodes from unauthorized routers.

It keeps customer-specific authentication and business rules outside the core runtime. It also ensures denied access fails safely and secrets do not appear in traces.

sidecar-auth-context — Skill by extra-org

Install

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.

agentmods

npx agentmods add skills/extra-org/extra/sidecar-auth-context

Any agent

npx skills add extra-org/extra --skill sidecar-auth-context

Clone the repo

git clone --depth 1 https://github.com/extra-org/extra

Made for: Claude Code, Codex.

Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 486 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. Scan, not verified.

Origin original No closer match found in the catalogue.

Token cost

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	$0.00041	$0.00486
Opus 5	$0.00020	$0.00243
Sonnet 5	$0.00008	$0.00097
Haiku 4.5	$0.00004	$0.00049

Measured 3d ago against content hash 1fefbee9299b, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

sidecar-auth-context 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 3d 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.

.claude/skills/sidecar-auth-context/SKILL.md · 64 lines

What it actually says

Skill: Plugin Context & Access

When to use this skill

Use this when working on resolver plugins, the fixed access plugin contract, mapping resolver outputs into ExecutionContext, or protected-node filtering. Primary task: tasks/0006-sidecar-auth-context.md.

Files to read first

AGENTS.md
docs/SIDECAR_CONTEXT_AUTH.md
docs/ARCHITECTURE.md
docs/PROMPT_RENDERING.md

Architecture rules

The runtime contains no customer-specific auth/business logic.
Resolver plugins fill prompt variables before a node runs.
Tool plugins are separate and run during LLM execution.
Protected nodes are hidden from routers unless the access plugin allows them.
Access failures fail closed.
Secrets are redacted in traces.

Implementation rules

Implement plugin integration in src/agentplatform/context.
Build ctx from request headers and request data.
Call resolver plugin methods declared in top-level resolvers.
If any node has protected: true, require plugins/access.py with AccessResolver.can_access(ctx, node_id) -> bool.
Keep plugin instances shared where appropriate; keep request data on ExecutionContext.

Validation checklist

No customer-specific logic in the runtime.
Resolver outputs are request-scoped.
Protected nodes are filtered before routing.
Deny/error cases fail closed and are traced.
Secrets redacted in traces.
Tests use fake plugins covering allow/deny/error.
make check passes.

Common mistakes to avoid

Implementing auth/tenant/business rules inside the engine.
Failing open when access plugin raises.
Exposing resolver plugins to the LLM as tools.
Logging raw tokens/secrets in the trace.

Changes

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.

3d ago First seen · 64 lines · 41 tokens per session scan A 1fefbee9299b

Subscribe to this mod's changes

sidecar-auth-context is a skill published in the GitHub repository extra-org/extra (108 stars, last pushed 5d ago), licensed MIT. It adds 41 tokens to every session and 486 once invoked, about $0.0002 per session on Opus 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 2026-08-30.

Building agents Security agentic agentic-ui ai ai-agents ai-orchestration ai-orchestration-engine

batch

Execute batch operations on multiple files in parallel. Automatically discovers files, splits into chunks, and processes with parallel worker agents. Use /batch followed by operation and file pattern.

QwenLM/qwen-code · 37 tokens

notion

Notion API for creating and managing pages, databases, and blocks. Use when the user wants to create a Notion page, query a Notion database, update Notion properties, search Notion, add content to Notion, manage Notion blocks, or interact with Notion data sources and workspaces via the API.

elizaOS/eliza · 69 tokens

sidecar-auth-context