docs(auth): add Fill from Managed Auth how-to

[bmsaadat]

Part of KERNEL-2298.

Adds auth/fill-from-managed-auth, a how-to under Fill from Vault, walking through: log in through Managed Auth, create a credential item that references the connection, attach the vault to a browser, fill. Also cross-links it from the Fill from Vault overview.

Do not merge yet. The page documents the managed_auth credential provider from kernel/kernel#4285, which is not in production. Merge order: API in production, SDK release, then this page.

Open items before it leaves draft:

• SDK snippets follow the existing vaults.items call shapes; re-check them against the Stainless preview builds once those build cleanly (the current builds on #4285 hit merge conflicts).
• The GitHub login selectors were checked against the live page. The authenticator-code selector in the last step was not, since that page needs a session.
• If the provider is still gated per organization at merge time, add an "enabled for your organization" line like the hCaptcha page.

mint broken-links passes locally.

🤖 Generated with Claude Code

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Note

Low Risk
Documentation and nav-only changes; no runtime code. Merge is intentionally gated on the managed_auth vault provider shipping in production.

Overview
Adds auth/fill-from-managed-auth, a how-to for wiring Managed Auth–saved credentials into the existing vault fill flow without re-collecting secrets. The guide covers when to use it vs Fill from Vault or full Managed Auth, requirements (Kernel-stored credential, same project), a GitHub walkthrough (login → credential item with spec.provider: managed_auth → vault attach → navigate → fill, including optional TOTP), item shape/status reasons, differences from kernel credential items, and security notes.

Navigation and cross-links: registers the page under Fill from Vault in docs.json and points Fill from Vault’s credential-sources section at the new guide.

Snippets: six reusable MDX snippets (login, verify saved credential, upsert item, sample API response, navigate, fill) in TypeScript, Python, and cURL where applicable.

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[mintlify]

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Project	Status	Preview	Updated
Kernel	🟢 Ready	View Preview	Sep 22, 2026, 9:59 PM

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[cursor]

Risk assessment: Very Low

I reviewed the diff (9 files, +308/−2). Every change is documentation for the Mintlify site:

• New how-to page auth/fill-from-managed-auth.mdx and snippet files with TypeScript, Python, cURL, and an example JSON response.
• One cross-link sentence in auth/fill-from-vault.mdx.
• A sidebar entry for the new page in docs.json.

No application code, infrastructure, CI, authentication implementation, or agent-instruction files are modified. docs.json only adds the new page to navigation. Code owner review is not required on main.

Approving.

  

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[cursor]

Risk assessment: Very Low

Re-checked the current head (d200cc1). The diff is still documentation for the Mintlify site only: a new how-to (auth/fill-from-managed-auth.mdx), six example snippets, one cross-link in auth/fill-from-vault.mdx, and a sidebar entry in docs.json (9 files, +308/−2).

No application code, infrastructure, CI, authentication implementation, or agent-instruction files changed. require_code_owner_review is off on main, and there is no CODEOWNERS file.

This automation already approved this same commit. Risk has not increased, so that approval stands and I am not approving again.

  

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[cursor]

Cursor Bugbot has reviewed your changes using default effort and found 1 potential issue.

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[cursor]

Dense submit-step paragraph

Low Severity

The submit step packs several separate actions and caveats into one paragraph: submit and verify the login, optionally navigate and fill totp, note that Kernel generates the code at fill time, watch for auto-submit, and handle any other prompt. Those are distinct steps, so the guidance is hard to scan and easy to miss.

 

^{Triggered by learned rule: Use bullet lists when covering multiple distinct points in guides}

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