feat: add AGX microVM SSH-lease provider

[zozo123]

Summary

Adds provider: agx for direct AGX Linux microVM leases, closing #341.

AGX exposes fast-booting microVMs over a workspace SSH gateway — ssh <user>+<instance>@workspace.agx.so ("if it can ssh, it can work on AGX"). That maps to an SSH-lease backend (ProviderKindSSHLease), so core keeps ownership of slugs, per-repo claims, per-lease SSH keys, rsync sync, command streaming, and list/status rendering, while the adapter owns only the AGX control-plane instance lifecycle and per-lease key registration.

Built to mirror the existing self-contained SSH-lease sandbox providers (Sprites/Morph): in-package API client, core helper reuse, and label-based ownership.

What's included

• internal/providers/agx/: provider.go (registration + Spec), backend.go (Acquire/Resolve/List/Doctor/ReleaseLease/Touch/Cleanup + flags), client.go (control-plane client), core.go (core helper wrappers), and backend_test.go.
• Registration in internal/providers/all/all.go.
• AGXConfig config surface (env → file → flags). The API key is read only from the environment (CRABBOX_AGX_API_KEY / AGX_API_KEY / AGX_TOKEN), never persisted to config or placed on argv, per AGENTS.md.
• Docs: docs/providers/agx.md, docs/providers/provider-metadata.json, regenerated docs/providers/README.md matrix, root README provider table, docs/source-map.md, and a CHANGELOG entry.

Capabilities

FeatureSSH, FeatureCrabboxSync, FeatureCleanup; Linux only; CoordinatorNever. --class, --type, and --tailscale are rejected. Conservative feature set on purpose — no over-claimed native checkpoint/fork surfaces.

Config / secret implications

Var	Purpose
CRABBOX_AGX_API_KEY / AGX_API_KEY / AGX_TOKEN	control-plane API key (env only)
--agx-api-url / --agx-workspace / --agx-user / --agx-work-root / --agx-region / --agx-image	provider flags

Early-access caveat

AGX ships Summer 2026 and does not publish a stable control-plane contract yet. The /v1/instances lifecycle API modeled here is provisional and overridable via --agx-api-url / --agx-workspace; the SSH transport follows AGX's documented <user>+<instance>@<workspace> shape. Flagging for maintainer review since the original issue is tagged needs-product-decision — happy to adjust the auth/lifecycle contract to whatever AGX publishes.

Verification

gofmt -l internal/providers/agx
go vet ./...
go test -count=1 ./internal/cli ./internal/providers/...
go test -race ./internal/providers/agx ./internal/providers/all
bash scripts/check-docs.sh   # command docs, provider matrix, links, docs site

All pass; tests use a stubbed HTTP transport and run without live credentials.

🤖 Generated with Claude Code

[clawsweeper]

Codex review: needs real behavior proof before merge. Reviewed June 14, 2026, 11:19 AM ET / 15:19 UTC.

Summary
The PR adds a built-in SSH-only AGX provider with local-claim lease tracking, AGX config/flags, provider registration, tests, and provider documentation.

Reproducibility: yes. for the review finding: source inspection of the PR head shows agxSSHTarget always sets DisableHostKeyChecking: true for the AGX workspace host. The broader provider feature still lacks live AGX reproduction evidence.

Review metrics: 3 noteworthy metrics.

• Diff surface: 12 files changed, +815/-3. This is a full provider addition spanning code, config, docs, metadata, and tests, so proof and trust checks matter before merge.
• New provider surface: 1 provider, 3 AGX config fields, 3 AGX flags. The PR creates a new user-selectable provider and persistent configuration surface.
• SSH trust change: 1 new SSH target disables host-key checking. The provider’s main runtime path changes SSH trust behavior for the AGX workspace gateway.

Merge readiness
Overall: 🧂 unranked krab
Proof: 🧂 unranked krab
Patch quality: 🧂 unranked krab
Result: blocked until real behavior proof is added.

Overall follows the weaker of proof and patch quality, so missing proof can cap an otherwise strong patch.

Rank-up moves:

• Remove or explicitly justify the AGX host-key bypass with maintainer-approved trust handling.
• Attach redacted terminal output, logs, screenshot, or recording from a real AGX warmup/status/run/stop flow.
• Update the PR body so it matches the SSH-only current head instead of the removed REST/API-key design.

Proof guidance:

• [P1] Needs real behavior proof before merge: No after-fix live AGX proof is present; add redacted terminal output, logs, screenshot, or recording for warmup/status/run/stop, then update the PR body so ClawSweeper re-reviews or ask a maintainer to comment @clawsweeper re-review.

Risk before merge

• [P1] No redacted live AGX proof is present for the real workspace SSH gateway, BYO-key authentication, provisioning-on-connect, command execution, or local-only release flow.
• [P1] The linked provider request is still labeled as needing product decision, and the current PR comment says provisioning lifecycle/key registration remains inferred until AGX early access opens.
• [P1] The PR body still describes the removed REST/API-key/Cleanup implementation, so maintainers could review or release against stale provider-contract claims unless it is updated before merge.

Maintainer options:

1. Fix SSH trust and prove live AGX (recommended)
   Remove the unconditional host-key bypass or replace it with a maintainer-approved trust model, update the stale PR body, and attach redacted live AGX warmup/status/run/stop proof before merge.
2. Pause for provider-contract approval
   Maintainers can pause this PR until AGX early access confirms the SSH provisioning, key-registration, and local-only release contract.
3. Accept the provisional provider knowingly
   Maintainers may intentionally accept the early-access AGX limitations, but the SSH trust issue and missing live proof should be explicitly owned first.

Next step before merge

• [P1] Human follow-up is needed because the PR requires contributor-provided live AGX proof and maintainer approval for the provider contract, even though the host-key finding itself is mechanically fixable.

Security
Needs attention: The current diff disables SSH host-key checking for the AGX gateway while relying on user-managed SSH credentials.

Review findings

• [P1] Preserve host-key verification for AGX SSH — internal/providers/agx/backend.go:272

Review details

Best possible solution:

Land AGX only after maintainers approve the built-in SSH-only provider contract, host-key handling is safe, the PR body matches the current head, and redacted live AGX proof shows the real lease flow.

Do we have a high-confidence way to reproduce the issue?

Yes for the review finding: source inspection of the PR head shows agxSSHTarget always sets DisableHostKeyChecking: true for the AGX workspace host. The broader provider feature still lacks live AGX reproduction evidence.

Is this the best way to solve the issue?

No, not yet. The SSH-only provider shape is plausible, but merge-ready implementation should preserve normal SSH host-key protections or use an explicit maintainer-approved trust model, plus product approval and live provider proof.

Full review comments:

• [P1] Preserve host-key verification for AGX SSH — internal/providers/agx/backend.go:272
agxSSHTarget always disables host-key checking for workspace.agx.so, but this provider authenticates with the operator's own AGX-registered SSH key and has no per-lease gateway trust bootstrap. That makes the first real AGX connection accept any host claiming to be the workspace gateway, so the provider should use normal known-host verification or an explicit, reviewed trust model before merge.
  Confidence: 0.86

Overall correctness: patch is incorrect
Overall confidence: 0.86

AGENTS.md: found and applied where relevant.

Codex review notes: model internal, reasoning high; reviewed against d3d1891aafa7.

Label changes

Label changes:

• add merge-risk: 🚨 security-boundary: The new provider disables SSH host-key checking for the AGX gateway while using the operator's own SSH key.

Label justifications:

• P2: This is a substantive new provider integration with limited blast radius and no existing-user regression shown.
• merge-risk: 🚨 auth-provider: The PR adds provider authentication and routing behavior for AGX that remains unproven against the real service.
• merge-risk: 🚨 security-boundary: The new provider disables SSH host-key checking for the AGX gateway while using the operator's own SSH key.
• rating: 🧂 unranked krab: Overall readiness is 🧂 unranked krab; proof is 🧂 unranked krab and patch quality is 🧂 unranked krab.
• status: 📣 needs proof: The PR needs real behavior proof before ClawSweeper can clear the contributor ask. Needs real behavior proof before merge: No after-fix live AGX proof is present; add redacted terminal output, logs, screenshot, or recording for warmup/status/run/stop, then update the PR body so ClawSweeper re-reviews or ask a maintainer to comment @clawsweeper re-review.

Evidence reviewed

Security concerns:

• [medium] AGX SSH gateway skips host-key verification — internal/providers/agx/backend.go:272
  The provider sets DisableHostKeyChecking: true for the workspace gateway, so users cannot rely on standard SSH known-host verification when using their AGX-registered key.
  Confidence: 0.86

What I checked:

• AGENTS policy read and applied: AGENTS.md was read fully; its provider-neutral architecture, secret-handling, generated-output, and full-reference guidance affected this provider review. (AGENTS.md:11, d3d1891aafa7)
• AGX target disables SSH host-key checks: The PR-head AGX SSH target sets DisableHostKeyChecking to true for the workspace gateway. (internal/providers/agx/backend.go:272, 9101cd51d253)
• Core SSH behavior for that flag: When DisableHostKeyChecking is true, Crabbox passes StrictHostKeyChecking=no and UserKnownHostsFile=/dev/null instead of accept-new with a known_hosts file. (internal/cli/ssh.go:535, d3d1891aafa7)
• AGX docs describe BYO SSH key auth: The PR-head docs say AGX uses the operator's own AGX-registered SSH key and no API token, making the gateway trust decision security-sensitive. (docs/providers/agx.md:56, 9101cd51d253)
• No live proof in PR discussion: The PR body and latest contributor comment report local/unit/docs checks only; the latest comment says live lifecycle/key-registration details remain inferred and pending product decision. (9101cd51d253)
• Linked provider request is still product-gated: The linked AGX issue remains open and labeled needs-product-decision / needs-maintainer-review.

Likely related people:

• steipete: Recent history touches provider registration, claim handling, coordinator/provider-adjacent work, and current release state that this PR depends on. (role: recent area contributor and merger; confidence: high; commits: d3d1891aafa7, f6b4a9765285, 71896637009c; files: internal/providers/all/all.go, internal/cli/claim.go, internal/cli/config.go)
• coygeek: GitHub history shows many recent built-in provider additions and hardening passes across registration, config, docs, lifecycle, ownership, and live-smoke surfaces similar to AGX. (role: recent provider lifecycle contributor; confidence: high; commits: 4003a3000972, 460e241d1b71, a71c8a3a29aa; files: internal/providers/all/all.go, internal/cli/config.go, internal/providers/morph/backend.go)
• vincentkoc: History shows claim serialization and Sprites ownership/key fixes, relevant because AGX mirrors a claim-backed SSH-lease provider shape. (role: adjacent claim and Sprites contributor; confidence: medium; commits: 3c1ca6a5311a, addb3b2dcc84, 0cfb42f3ba39; files: internal/cli/claim.go, internal/providers/sprites/backend.go)
• zozo123: Although they authored this PR, they also appear in current-main history for prior provider work including OpenComputer, Islo, Windows Sandbox, and smolvm. (role: prior provider contributor; confidence: medium; commits: 3b92643ab361, f6ad6f84ca33, 973efedd2c87; files: internal/providers/opencomputer, internal/cli/config.go, internal/providers/smolvm)

What the crustacean ranks mean

• 🦀 challenger crab: rare, exceptional readiness with strong proof, clean implementation, and convincing validation.
• 🦞 diamond lobster: very strong readiness with only minor maintainer review expected.
• 🐚 platinum hermit: good normal PR, likely mergeable with ordinary maintainer review.
• 🦐 gold shrimp: useful signal, but proof or patch confidence is still limited.
• 🦪 silver shellfish: thin signal; proof, validation, or implementation needs work.
• 🧂 unranked krab: not merge-ready because proof is missing/unusable or there are serious correctness or safety concerns.
• 🌊 off-meta tidepool: rating does not apply to this item.

Shiny media proof means a screenshot, video, or linked artifact directly shows the changed behavior. Runtime, network, CSP, and security claims still need visible diagnostics.

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[zozo123]

Updated the provider to match AGX's published interface after checking their docs.

Research finding: AGX (agx.so) currently publishes no control-plane API, auth contract, or CLI — only the SSH connection shape ssh <user>+<instance>@workspace.agx.so and an explicit stance: "No SDK required, no custom client — if it can ssh, it can work on AGX." It ships Summer 2026 and is built on Loophole Labs' Firecracker/CRIU/Drafter stack.

Change: the first draft invented a /v1/instances REST control plane + API key, which contradicts that "no SDK / no custom client" model. This revision commits only to the documented SSH interface:

• Removed the REST client and API-key requirement; auth uses the operator's own SSH key (cfg.SSHKey, registered with AGX during onboarding), like the Static SSH provider.
• Provision-on-connect: build the <user>+<instance> target and wait for SSH readiness; the slug is the stable instance name.
• List/Resolve are backed by local lease claims; release is local-only (AGX reclaims idle sandboxes). Dropped FeatureCleanup since there's no inventory API.
• AGXConfig trimmed to workspace / user / workRoot.

Still pending a maintainer/product decision (the original issue is tagged needs-product-decision): provisioning lifecycle, key-registration, and any future management API remain inferred from the homepage because AGX hasn't published them. Happy to align to whatever AGX ships once early access opens.

Verified: gofmt, go vet ./..., go test ./internal/cli ./internal/providers/..., go test -race ./internal/providers/agx, and scripts/check-docs.sh all pass. Tests need no live credentials.