description	kind
An immutable snapshot of this run's environment that remembers which layer supplied each value, for packages that must resolve user-facing values without trusting a flattened process.env.	package-library

@deepseek-ai/dsh-launch-environment

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Summary

dsh-launch-environment freezes this run's environment at launch into an immutable snapshot that records which layer supplied each value. Resolving a name searches the layers from most to least trusted — the inherited process environment, the invoking directory's .env, then the Harness home's .env — so the winning value always carries its source. A caller can also resolve from a named subset of layers, which is a refusal rather than a demotion: omitted layers are unreachable no matter how trust ordering changes later. Values still reach process.env for config expressions and third-party libraries, but nothing the harness resolves treats that flattened view as authoritative. It is a zero-dependency library that product packages import directly; a cordis.yml cannot load it.

Use this package
Understand the implementation
Further Exploration
Known Limitations and Deferred Work
Dev Note

Use this package

Resolve user-facing values through the snapshot instead of process.env whenever the layers are not equally trusted — for example a credential override a caller must never take from a project directory.

Resolving a value

import { launchEnvironmentOf } from '@deepseek-ai/dsh-launch-environment'

declare const ctx: import('@deepseek-ai/cordis').Context
const endpoint = launchEnvironmentOf(ctx).get('DEEPSEEK_BASE_URL')?.value

get(name) searches every layer, most trusted first. getFrom(name, sources) searches only the named layers without changing that trust order — a caller that must never accept a layer leaves it out of the list, so no future reordering can let it back in.

How layers rank

Layer	What it is
Inherited process environment	What the launching shell, CI job, or container passed in — this run's explicit intent
`<invocation cwd>/.env`	The project the harness was launched in, which the product trusts to configure its own agent
`$DSH_HOME/.env`	The user's own machine-level defaults

Names match the way the platform matches them: exactly on POSIX, case-insensitively on Windows. A case-sensitive lookup on Windows would rank the wrong layer — a shell's deepseek_api_key and a project .env's DEEPSEEK_API_KEY are one variable to the OS.

When no launcher booted the tree

launchEnvironmentOf(ctx) returns the launcher's snapshot when the product CLI booted the tree, and otherwise the inherited environment as the only layer. The fallback does not weaken the rules: an SDK host or a bare cordis.yml discovered no files, so everything it has is the environment it was launched with.

Understand the implementation

Implementation internals — click to expand

The snapshot is built on one separation: the launcher owns which files exist, and the snapshot owns how values rank.

Source map

File	Role
`src/index.ts`	`createLaunchEnvironmentSnapshot`, `launchEnvironmentOf`, and the `ctx.launchEnvironment` slot
`src/invariant.ts`	Invariant companion (no runtime invariant; the snapshot is frozen before any fiber starts)

How the snapshot stays frozen

createLaunchEnvironmentSnapshot copies every layer's values at construction, so a later mutation of the source object cannot change the snapshot. Lookups walk a canonical trust order regardless of construction order; on Windows, names are folded to uppercase before storage so case variants cannot split precedence.

What omission means

getFrom filters by the canonical order, never by the caller's list order. Omitting a layer is a refusal: the value is unreachable through that call, which is the mechanism a caller uses when a layer must never influence a specific decision.

Further Exploration

Read these pages when you need the launcher that builds the snapshot or the consumers that resolve through it.

Boot package — the launcher that fills ctx.launchEnvironment before any config entry mounts.
Credentials store — resolves stored credentials against the snapshot's layers.
DeepSeek provider — reads provider configuration through the launch environment.

Known Limitations and Deferred Work

These limits define when the snapshot is not a security boundary. They are current package constraints, not a task backlog.

The snapshot is not a subprocess boundary — every layer is also materialized into process.env, so ordinary project variables reach child processes under dsh-subprocess's scrub; the product launcher's .env contract rejects bootstrap variables before materialization.
No per-workspace layer — the project layer is the invoking directory, fixed at launch; a workspace selected later in the Web UI contributes nothing, deliberately, because following it would let a model's own workspace change the harness environment mid-session.

Dev Note

Working context for maintainers — click to expand

None.

README.md