> For the complete documentation index, see [llms.txt](https://docs.sealsecurity.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.sealsecurity.io/introduction/seal-approach.md).

# The Seal approach

If [the remediation problem](/introduction/remediation-problem.md) is "upgrades are expensive and frequently impossible", the Seal answer is to remove the upgrade requirement.

Seal builds **sealed packages**: drop-in replacements for the public versions you already use, with security fixes backported in. The version stays the same. The API stays the same. The dependencies stay the same. Only the vulnerable code changes.

The four pages below explain the model, the package, the delivery mechanics, and the trust posture.

* [Drop-in replacements, not upgrades](/introduction/seal-approach/drop-in-replacements.md): the mental model.
* [What a sealed package is](/introduction/seal-approach/sealed-packages.md): origin versions, backported fixes, the `-sp[N]` iteration, what is covered by default, and what an open vulnerability means.
* [How sealed packages are delivered](/introduction/seal-approach/sealing-approaches.md): build-time dependency sealing versus post-build artifact sealing, and when each applies.
* [Trust by default](/introduction/seal-approach/trust-by-default.md): code diff, attestations, and signing. Deeper material in [Trust, transparency & compliance](/trust/why-this-matters.md).