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agentctlv1

Reusable packs

A pack is reviewed reusable workflow content. It is not an in-process native plugin. The manifest API is agentctl.dev/pack/v1alpha1 and uses a fully qualified dotted name, semantic version, agentctl compatibility constraint, optional dependencies, and exported actions, agents, tools, and sub-workflows.

Sources and resolution

Section titled “Sources and resolution”

Workflow roots and transitive dependencies use an exact source:

packs:
  - name: example.utility
    version: "^1.0"
    source:
      path: packs/example.pack.yaml

Supported sources are:

  • a contained local path;
  • a Git https URL with a full 40-character rev and contained manifest;
  • an immutable https tar-gzip archive URL with SHA-256 integrity and a contained manifest.

Loopback HTTP and contained file: Git URLs exist only for deterministic local fixtures. URLs with credentials, query parameters, or fragments are rejected. Git branches and tags are not accepted as revisions. Archive redirects, symlinks, hardlinks, special files, path escapes, more than 1,024 entries, compressed content over 16 MiB, and expanded content over 64 MiB are rejected.

Each dependency names its source and semantic constraint:

dependencies:
  example.base:
    version: "^2.1"
    source:
      git: https://github.com/example/base-pack.git
      rev: 0123456789abcdef0123456789abcdef01234567
      manifest: agentctl.pack.yaml

Resolution is deterministic because every requirement identifies one immutable candidate. Conflicting versions or sources, duplicate identities, missing dependencies, and cycles fail with validation exit 2. There is no hosted registry and no implicit search order.

Lockfile workflow

Section titled “Lockfile workflow”

Generate and commit agentctl.pack.lock beside the workflow:

Terminal window
agentctl packs lock workflow.yaml
agentctl packs verify-lock workflow.yaml --locked
agentctl packs update workflow.yaml
agentctl packs update workflow.yaml --pack example.utility

The lock API is agentctl.dev/pack-lock/v1. It records agentctl compatibility, pack identity and concrete version, exact source, manifest digest, dependency edges, signature metadata, and trust result. Entries are sorted by pack name. An update resolves the complete graph; --pack validates and identifies the requested root while preserving graph-wide consistency.

Execution uses the lock whenever it exists. --locked requires it and rejects workflow, source, graph, digest, compatibility, signature, trust, or unreachable entry drift. --offline permits local paths and requires Git/archive cache hits. Legacy exact path plus integrity references remain readable without a lock and emit a migration warning.

Integrity and trust

Section titled “Integrity and trust”

SHA-256 binds the lock to exact bytes. It proves sameness, not publisher identity. Optional keyless publisher verification uses the standard Sigstore bundle format and the embedded Sigstore public-good trust root:

packTrust:
  unsigned: deny
  identities:
    - identity: https://github.com/example/repository/.github/workflows/release.yml@refs/tags/v1.2.0
      issuer: https://token.actions.githubusercontent.com
packs:
  - name: example.utility
    version: "=1.2.0"
    source:
      path: packs/example.pack.yaml
    signature:
      bundle: packs/example.pack.sigstore.json
      identity: https://github.com/example/repository/.github/workflows/release.yml@refs/tags/v1.2.0
      issuer: https://token.actions.githubusercontent.com

Verification checks the artifact signature, certificate chain, identity, issuer, transparency-log proof, signed timestamp, and locked bundle digest. The bundle is sufficient for offline cryptographic verification, subject to the freshness of the trust root embedded in the installed agentctl version. See the Sigstore bundle model and Cosign blob verification.

packTrust.unsigned is deny, warn, or allow, with warn as the default. Unsigned process-capable packs are always blocked unless allowUnsignedProcess: true is also explicit. That exception is a review acknowledgement, not proof of publisher identity or process isolation.

Manifest policy defaults remain inspectable metadata and never weaken the invoking workflow policy. Exported definitions are qualified as <pack-name>.<item-name> before compilation.

Verification evidence

Section titled “Verification evidence”

Unit fixtures cover semantic constraints, deterministic ordering, conflicts, cycles, path containment, tamper, locked drift, pinned Git cache reuse, offline misses, bounded archives, archive links, valid and invalid Sigstore bundles, identity policy, unsigned process denial, and dependency reachability. Packaged acceptance scenario 42 verifies the checked-in transitive example, locks an extension pack, proves that its process cannot start before explicit trust authorization, executes it once, and replays without another invocation.

Canonical source: docs/PACKS.md. Verified against agentctl commit 2aeaa88fba71162206b5f08f5bda4f0150247e4f.