go-authcrunch: Skill for Codex

.codex/skills/refresh-token-identity/SKILL.md

refresh-token-identity is a skill for Codex from greenpau/go-authcrunch. It costs 36 tokens per session (740 once invoked), scanned A, original, Apache-2.0.

A guide for the evidence carried from login into refresh-token issuance. It covers completed multi-factor authentication, immutable user identity, credential versions, and checks that must pass before a refresh token is created.

In plain words
What is it for?
Use it when changing login proof, multi-factor authentication, sandbox login redemption, credential-version invalidation, identity reloading, or checks before issuing refresh tokens.
Why use it?
It prevents stale or incomplete login proof from being reused and stops changes such as password resets or policy updates from being overlooked during token issuance.

Skill for Codex

Written for Codex: agents/openai.yaml present.

This is greenpau/go-authcrunch's own configuration. It tells Codex how to work on go-authcrunch itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything go-authcrunch configures →

Reuse

Borrowing it

Nothing to install: this file belongs to greenpau/go-authcrunch. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/greenpau/go-authcrunch/main/.codex/skills/refresh-token-identity/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/greenpau/go-authcrunch

Made for: Codex.

Wrote 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.

agentmods badge for refresh-token-identity

README.md
[![agentmods](https://agentmods.dev/badge/skills/greenpau/go-authcrunch/refresh-token-identity/github.svg)](https://agentmods.dev/skills/greenpau/go-authcrunch/refresh-token-identity)
Your own site
<a href="https://agentmods.dev/skills/greenpau/go-authcrunch/refresh-token-identity"><img src="https://agentmods.dev/badge/skills/greenpau/go-authcrunch/refresh-token-identity/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.

agentmods 80×15 button for refresh-token-identity

Your own site · 80×15
<a href="https://agentmods.dev/skills/greenpau/go-authcrunch/refresh-token-identity"><img src="https://agentmods.dev/badge/skills/greenpau/go-authcrunch/refresh-token-identity.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 740 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00036 $0.00740
Opus 5 $0.00018 $0.00370
Sonnet 5 $0.00007 $0.00148
Haiku 4.5 $0.00004 $0.00074

Measured yesterday against content hash 371c5c364d10, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-14, from the pricing page.

Security

Grade A, and why

refresh-token-identity 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.

.codex/skills/refresh-token-identity/SKILL.md · 68 lines

How it starts

The opening of the file, as written. The whole thing — 68 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Refresh Token Identity

Ownership and Evidence

pkg/authn/login_proof.go, sandbox_user.go, handle_http_sandbox.go, and handle_json_login.go carry login evidence into the shared issuer. pkg/authn/cache/sandbox.go owns Acquire, SandboxLease, and single-use Redeem. Serialize a sandbox request through its lease; successful checkpoint checks alone do not prevent two requests from minting two refresh families.

Capture immutable user ID, credential version, and backend reload epoch when identification/authentication begins. Record actual successful authentication time and method on the server and retain them through MFA. JSON input and transformed claims cannot supply or upgrade this evidence. Keep requests.AuthenticationEvidence and the private fields on user.User out of JSON/XML/YAML; preserve the relevant fields when cloning a user.

Every required checkpoint must pass before redemption and issuance. MFA enrollment mutates credentials and is not proof of authentication with the new factor: require a new completed login. A reset or policy change between password verification and MFA must invalidate the pending evidence. Password, API key, TOTP, WebAuthn, SSH, and GPG paths must record only methods actually verified. Do not infer authentication strength from display/profile attributes.

Local Identity Contract

pkg/identity/refresh.go owns RefreshIdentity, WithRefreshIdentity, and credential-version invalidation. pkg/ids/local/refresh.go is the adapter and exposes RevokeUserSessions(ctx, immutableUserID). The persisted identity.User.CredentialVersion defaults to zero for legacy files; new security mutations advance it without rewriting every existing account in bulk.

In pkg/identity/database.go, password change/reset/update, MFA add/delete, account disable/enable, and challenge-rule changes must invalidate captured versions. Explicit session revocation uses the same boundary. Deletion denies lookup; recreating a username must not reuse its immutable ID. Database reload changes LoadedAt evidence so restoring an older file cannot restore refresh eligibility.

Read the full file on GitHub · 68 lines

Files

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.

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.

  1. yesterday First seen · 68 lines · 36 tokens per session scan A 371c5c364d10

Subscribe to this mod's changes

refresh-token-identity is a skill published in the GitHub repository greenpau/go-authcrunch (59 stars, last pushed yesterday), licensed Apache-2.0. It adds 36 tokens to every session and 740 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 2026-09-13.

Related

Other skills, from other repositories

mem0-oss-to-platform

Plan and then execute a migration of a project from the mem0 open-source / self-hosted SDK (the local Memory class) to the mem0 Platform / hosted / managed SDK (the MemoryClient class). Use this whenever a developer wants to move, switch, or migrate their mem0 usage off OSS/self-hosted to the hosted API — e.g.…

mem0ai/mem0 · 273 tokens

agui-dotnet-protobuf

Use the protobuf wire transport (instead of the default Server-Sent Events) for an AG-UI connection with the AG-UI .NET SDK — a compact binary event stream negotiated via the Accept header. USE FOR: making an AGUIChatClient prefer protobuf by wiring an AGUIEventStreamHandler with ProtobufEventStreamFormatter (then…

ag-ui-protocol/ag-ui · 162 tokens

azure-mgmt-botservice-dotnet

Azure Resource Manager SDK for Bot Service in .NET. Management plane operations for creating and managing Azure Bot resources, channels (Teams, DirectLine, Slack), and connection settings. Triggers: "Bot Service", "BotResource", "Azure Bot", "DirectLine channel", "Teams channel", "bot management .NET", "create bot".

microsoft/skills · 78 tokens

fastapi-router-py

Create FastAPI routers with CRUD operations, authentication dependencies, and proper response models. Use when building REST API endpoints, creating new routes, implementing CRUD operations, or adding authenticated endpoints in FastAPI applications.

microsoft/skills · 46 tokens

aws-sdk-java-v2-core

Provides AWS SDK for Java 2.x client configuration, credential resolution, HTTP client tuning, timeout, retry, and testing patterns. Use when creating or hardening AWS service clients, wiring Spring Boot beans, debugging auth or region issues, or choosing sync vs async SDK usage.

giuseppe-trisciuoglio/developer-kit · 62 tokens

telnyx-messaging-hosted-curl

Set up hosted SMS numbers, toll-free verification, and RCS messaging. Use when migrating numbers or enabling rich messaging features. This skill provides REST API (curl) examples.

team-telnyx/ai · 45 tokens