Host Environment Variables

Slipway keeps repository policy, runtime host facts, and secrets on separate surfaces. Use .slipway.yaml for version-controlled repo policy. Use environment variables for facts supplied by the current host session and for secrets that must never be written to project config.

The current machine-readable authority is:

slipway config list --env
slipway config list --env --json

The JSON form includes each variable’s scope, secret status, value syntax, accepted values when constrained, examples, and unset behavior.

Runtime Host Scope

Runtime-host variables describe the current AI host session. They have no .slipway.yaml key because they describe host capability or identity, not repo policy.

Declaring Subagent Capability

Some governed skills require fresh subagent or delegated execution to preserve independent review evidence. When a skill says the host must declare subagent capability, the host-facing knob is:

SLIPWAY_HOST_CAPABILITIES=subagent

Accepted SLIPWAY_HOST_CAPABILITIES tokens:

Token	Meaning
subagent	Declares subagent dispatch capability available.
delegation	Alias that also satisfies the subagent capability.
none	Explicitly declares the capability unavailable.
unavailable	Explicitly declares the capability unavailable.

The value is a comma, semicolon, space, tab, newline, or carriage-return separated token list. Capability token matching is case-insensitive. Empty or unset does not mean unavailable; it means unknown. In that state next, run, or validate can surface a delegation authorization prerequisite plus named fallback options. Any other non-empty token still declares the host capability space; if it does not satisfy the required capability, Slipway treats that capability as unavailable rather than unknown.

When a host intentionally runs degraded same-context evidence, declare the fallback separately and record fallback evidence with the governed skill:

SLIPWAY_HOST_CAPABILITY_FALLBACKS=same_context_degraded

Skill-specific manual fallbacks include manual_plan_audit, manual_spec_compliance_review, manual_code_quality_review, manual_security_review, manual_independent_review, and manual_ship_verification. Fallback token matching is case-insensitive, and unrecognized fallback tokens are ignored. Fallback selection does not replace evidence requirements; it only makes the degradation explicit.

Context Ownership

Slipway does not watch or measure your context window. There is no context-pressure hook, no token-budget estimate, and no next context guard: the host owns the decision of when to compact in place or start a fresh session, using whatever native signal it has. The SessionStart hook advertises this contract and points at the optional slipway handoff surface for capturing an advisory continuation narrative. Governed continuity itself does not depend on that narrative — it comes solely from authoritative lifecycle state resumed via slipway status / slipway next, with no agent cooperation required.

The SessionStart hook payload carries two static, host-facing keys: slipway_entry_skill (the entry-skill routing pointer) and slipway_context_note (the note that Slipway does not watch context and that slipway handoff is optional advisory continuity). Both are routing/advisory context consumed by the host, not user-configured settings.

Handoff Owner

SLIPWAY_SESSION_OWNER sets the owner label recorded in handoff notes. When it is unset, empty, or whitespace-only, Slipway falls back to USER, then USERNAME, then machine hostname, then unknown.

Repo Policy And Secret Scope

Some repo policy has both a file key and an environment override. For GitHub Enterprise API routing, environment values win over file config, and file config wins over defaults:

Environment	File key	Notes
SLIPWAY_GITHUB_API_URL	github.api_url	HTTPS GitHub REST/GraphQL API base URL. Defaults to https://api.github.com.
SLIPWAY_GITHUB_API_ALLOWED_BASE_URLS	github.api_allowed_base_urls	Comma, semicolon, space, tab, newline, or carriage-return separated HTTPS allowlist for override hosts.

Secrets stay environment-only:

Environment	Notes
GH_TOKEN	Ambient token for https://api.github.com; preferred over GITHUB_TOKEN.
GITHUB_TOKEN	Ambient fallback token for https://api.github.com.
SLIPWAY_GITHUB_API_TOKEN	Token for an allowlisted override host only.

Ambient GH_TOKEN and GITHUB_TOKEN are not sent to override hosts. SLIPWAY_GITHUB_API_TOKEN is sent only after the override host is allowlisted and operator-confirmed.