deepseek-harness/docs/subsystems/settings.md

User Settings

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The user-settings seam of dsh-settings holds one user-owned document of per-namespace sections and resolves each registered namespace as schema defaults, then the registrant's composition base, then the user section. Providers such as dsh-settings-file store the raw document and push external edits; consumer plugins register a schema and read or observe the resolved value. Composition config stays in cordis.yml — a namespace carries only the user-editable subset.

Source: packages/settings/settings/src/index.ts

Identity

A namespace names one plugin-owned section of the user document. The brand prevents callers from mixing settings namespaces with other ids passed between packages or processes; construction validates lowercase kebab-case syntax.

/** Nominal id of one registered settings namespace. */
type SettingsNamespace = Branded<'SettingsNamespace'>

Registration

Registration binds a schemastery schema to a namespace on the calling plugin's fiber — disposing that fiber removes the namespace and its observers. The options carry the composition layer, the owner's effect timing, and an optional check for what the schema cannot express.

/** Registration options beyond the namespace schema. */
interface SettingsRegisterOptions<T> {
  /** Composition-layer values resolved below the user layer (entry-config subset). */
  base?: Partial<T>
  /** Owner's effect timing, surfaced to configuration UIs; defaults to `live`. */
  applies?: SettingsApplies
  /**
   * Reject a resolved section the owner could not act on, for constraints its
   * schema cannot express — a cross-field requirement, or one field's validity
   * depending on another's. Throwing here refuses the *write* that produced the
   * value, so a caller learns at `update`/`replace`/`mutate` instead of storing
   * something that would silently disable the owner.
   *
   * Kept separate from the schema because the schema is also what a
   * configuration surface renders and what an absent section resolves through;
   * folding a cross-field check into it would change both.
   *
   * Once the owner is registered, a stored section that fails this keeps the
   * namespace's last good value and warns, exactly as a schema failure does,
   * so an externally edited document cannot strand a running owner. At
   * registration there is no last good value yet, so a stored section that
   * already fails rejects the registration itself — again exactly as a schema
   * failure does.
   * @param value - the resolved section, schema-valid by construction.
   */
  validate?: (value: T) => void
}

validate runs after the schema admits a value, so it sees defaults and the composition base exactly as the owner will. dsh-llm-pi-ai uses it to refuse a provider profile it could not serve at the write that produced it, rather than storing one that would disable every route in its namespace.

applies is a UI hint, not a mechanism: a restart owner never watches, so its value is read once at construction and configuration surfaces can badge the pending change.

/** When a namespace's changes take effect for its owner. */
type SettingsApplies = 'live' | 'restart'

Owner scope

The scope is the owner-facing handle. update merges a sparse patch over the user section only (never into base); replace sets the section wholesale, which is the removal/reset path — keys absent from the replacement re-inherit base and schema defaults. Writes to one namespace are serialized in call order, and resolved values are deep-frozen snapshots.

/** Owner-facing handle for one registered namespace. */
interface SettingsScope<T> {
  /** Current resolved value: schema defaults, then `base`, then the user layer. */
  get(): T
  /**
   * Observe committed changes to this namespace's resolved value. Invocations
   * of one callback run asynchronously, one at a time, in commit order; a
   * rejection is contained and logged like a sync throw. After the disposer
   * returns, no further invocation starts — one already queued is skipped;
   * one already started still settles, and service disposal waits for it.
   * @param callback - invoked after each commit with the next and previous values.
   * @returns the disposer removing this observer.
   */
  watch(callback: (next: T, prev: T) => void | Promise<void>): () => void
  /**
   * Merge a partial patch into this namespace's user layer and persist it.
   * @param patch - plain-object patch over the user section; JSON-compatible data
   * only (non-JSON values reject with their path before anything persists).
   */
  update(patch: object): Promise<void>
  /**
   * Replace this namespace's user section wholesale; absent keys re-inherit
   * the composition `base` and schema defaults (`replace({})` resets all).
   * @param section - the complete next user section; JSON-compatible data only,
   * as for {@link update}.
   */
  replace(section: object): Promise<void>
}

Descriptors

describe() serializes every registered namespace for configuration surfaces: the schemastery toJSON() envelope drives schema-rendered forms, the resolved value fills them, and the detached base/user layers let a form mark user-overridden fields by presence. describe({ redactSecrets: true }) — mandatory on every wire surface — strips role('secret') fields from all three layers and enumerates their {path, set} slots so a page can render write-only inputs without ever receiving a secret.

/** One registered namespace as surfaced to configuration UIs. */
interface SettingsDescriptor {
  /** The registered namespace. */
  ns: SettingsNamespace
  /** Serialized schemastery schema (`schema.toJSON()`). */
  schema: unknown
  /** Current resolved value. */
  value: unknown
  /**
   * Monotonic revision of the raw user section this descriptor was read at.
   * Send it back as `expectedRevision` on a write to refuse a stale one.
   */
  revision: number
  /** Registrant's composition `base` layer (detached), when one was declared. */
  base?: unknown
  /**
   * Raw user section from the stored document (detached), when one exists and
   * is well-formed; a field's presence here is what marks it user-overridden.
   */
  user?: unknown
  /** Owner's declared effect timing. */
  applies: SettingsApplies
  /** Schema-declared secret positions; present only under `redactSecrets`. */
  secrets?: RedactedSecret[]
}

A caller that holds only the redacted descriptor cannot safely rebuild a section, so removals travel as path ops instead. Each descriptor also carries a revision over the raw section; a write may send it back as expectedRevision, and one that no longer matches is refused rather than applied over the writer that landed first.

/**
 * One path-addressed edit to a namespace's user section. Path mutation exists
 * for a caller holding an INCOMPLETE view of the section — a configuration UI
 * reads the redacted descriptor, which by construction never received the
 * `role('secret')` fields. Such a caller can name the field it means without
 * restating the section: a wholesale `replace` rebuilt from a redacted
 * document silently deletes every secret the wire never returned.
 */
type SettingsPathOp =
  | { op: 'set'; path: readonly string[]; value: unknown }
  | { op: 'unset'; path: readonly string[] }

/** Options for {@link SettingsProvider.describe}. */
interface SettingsDescribeOptions {
  /**
   * Strip `role('secret')` fields from `value`/`base`/`user` and enumerate
   * them in each descriptor's `secrets`. Every wire surface MUST pass this;
   * the verbatim default exists for same-process configuration UIs only.
   */
  redactSecrets?: boolean
}

Change commits

Every committed change — an in-process write or an externally observed provider edit — emits settings/updated (ns, next, prev, source) after the new value is authoritative, and never when the resolved value is deep-equal. The source tag separates the two entry paths.

/** Origin of one committed settings change. */
type SettingsUpdateSource = 'update' | 'provider'

Native document operations

SettingsDocumentOpenValue confirms that settings/openSettingsDocument prepared the provider-owned document and handed it to the native text editor. This operation does not accept a browser-selected Host path.

Cordis API

Generated from source by scripts/gen-cordis-catalog.ts (verified fresh by pnpm run verify-cordis-catalog in doc-sync; regenerate with pnpm run gen-cordis-catalog) — the language sides differ only in locale-specific paired document paths. Signature blocks use a ts cordis-catalog fence and keep the original source JSDoc; dispatch modes are defined in the primer, and the framework-inherited ctx API lives in cordis-api/inherited.md.

ctx.settings — SettingsProvider (abstract seam)

Abstract settings service. Providers implement raw-document storage (load/persist) and push external changes through Settings.publish; the base class owns namespace registration, resolution, validation, change detection, and the settings/updated commit event.

/**
 * Prepare the provider's user-editable document for a native editor. File
 * providers may materialize an absent document before returning its path;
 * non-file providers return undefined.
 * @returns the absolute local document path, or undefined for non-file storage.
 */
prepareDocument(): Promise<string | undefined>

/**
 * Register a namespace schema and receive its owner scope. The registration
 * is an effect on the calling plugin's fiber: disposing that fiber removes
 * the namespace and its observers. An invalid stored section fails the
 * registration itself — the earliest point where the schema can judge it.
 * @param ns - unique namespace; duplicate registration fails loud.
 * @param schema - schemastery schema resolving this namespace's value.
 * @param options - composition `base` layer and effect timing.
 * @returns the owner scope for reads, observation, and updates.
 * @throws {TypeError} when `ns` is not a lowercase hyphenated identifier.
 */
register<const Namespace extends string, T>( ns: Namespace & SettingsNamespaceInput<Namespace>, schema: z<T>, options?: SettingsRegisterOptions<T>, ): SettingsScope<T>

/**
 * Attach one optional-settings consumer to this provider. The consumer
 * registers its composition entry as the base layer while this provider is
 * present, then falls back to that entry if the provider detaches.
 * @param owner - consumer context whose unload suppresses fallback work.
 * @param ns - consumer-owned settings namespace.
 * @param schema - schema resolving the namespace.
 * @param entry - composition entry used as the base and fallback value.
 * @param hooks - source sink, change notification, and optional validation.
 * @throws {TypeError} when `ns` is not a lowercase hyphenated identifier.
 */
installSection<const Namespace extends string, T>( owner: Context, ns: Namespace & SettingsNamespaceInput<Namespace>, schema: z<T>, entry: T, hooks: SettingsSectionHooks<T>, ): void

/**
 * Describe every registered namespace for configuration surfaces, including
 * the composition `base` and raw user layers so a form can mark which fields
 * the user overrode (presence in `user`) and what a reset returns to.
 * @param options - redaction switch; wire surfaces must redact.
 * @returns one descriptor per registered namespace, in registration order.
 */
describe(options?: SettingsDescribeOptions): SettingsDescriptor[]

/**
 * Read one registered namespace's resolved value.
 * @param ns - the namespace to read.
 * @returns the resolved value, or `undefined` while unregistered.
 * @throws {TypeError} when `ns` is not a lowercase hyphenated identifier.
 */
get<const Namespace extends string>(ns: Namespace & SettingsNamespaceInput<Namespace>): unknown

/**
 * Merge a patch into one registered namespace's user layer, validate the
 * resolved candidate, persist through the provider, then commit and emit.
 * A validation failure rejects before anything is persisted. Writes to one
 * namespace are serialized: concurrent updates apply in call order, each
 * merging over the previous write's committed section.
 * @param ns - the registered namespace to update.
 * @param patch - plain-object patch over the user section.
 * @param expectedRevision - the descriptor `revision` the caller read; a
 *   namespace that moved past it rejects with {@link SettingsConflictError}.
 * @throws {TypeError} when `ns` is not a lowercase hyphenated identifier.
 */
async update<const Namespace extends string>( ns: Namespace & SettingsNamespaceInput<Namespace>, patch: object, expectedRevision?: number, ): Promise<void>

/**
 * Replace one registered namespace's user section wholesale, validate,
 * persist, then commit and emit. Keys absent from `section` fall back to the
 * composition `base` and schema defaults — this is the removal/reset path a
 * merge-only patch cannot express (`replace({})` re-inherits everything).
 * @param ns - the registered namespace to replace.
 * @param section - the complete next user section.
 * @param expectedRevision - the descriptor `revision` the caller read; a
 *   namespace that moved past it rejects with {@link SettingsConflictError}.
 * @throws {TypeError} when `ns` is not a lowercase hyphenated identifier.
 */
async replace<const Namespace extends string>( ns: Namespace & SettingsNamespaceInput<Namespace>, section: object, expectedRevision?: number, ): Promise<void>

/**
 * Apply path-addressed edits to one registered namespace's user section,
 * validate, persist, then commit and emit. The ops are applied to the
 * section as it stands when the write reaches the front of the queue, so a
 * caller never has to restate fields it did not touch — and, crucially,
 * cannot delete fields it never saw. This is the write path for any caller
 * holding a redacted view; `replace` remains the wholesale reset.
 * @param ns - the registered namespace to edit.
 * @param ops - ordered path edits; later ops observe earlier ones.
 * @param expectedRevision - the descriptor `revision` the caller read; a
 *   namespace that moved past it rejects with {@link SettingsConflictError}.
 * @throws {TypeError} when `ns` is not a lowercase hyphenated identifier.
 */
async mutate<const Namespace extends string>( ns: Namespace & SettingsNamespaceInput<Namespace>, ops: readonly SettingsPathOp[], expectedRevision?: number, ): Promise<void>

Source: packages/settings/settings/src/index.ts

ctx.settingsController — SettingsController

Host service backing the generated ctx.remote.settings namespace. Every remote read uses redactSecrets: true, so a role('secret') field cannot ride a response. Writes expose the settings service's merge, replacement, and path-addressed operations, and classify every provider refusal as settings/conflict or settings/rejected with the service's message.

/**
 * Describe every registered namespace for a configuration page: redacted
 * layered values plus the serialized schema the page renders its form from.
 * @returns provider writability, local-document presence, and one view per namespace.
 * @throws RemoteError when no settings provider is mounted.
 */
@Remote describe(): SettingsDescribeValue

/**
 * Merge a patch into one namespace's stored user section.
 * @param ns - namespace key to write.
 * @param patch - fields to merge into the user section.
 * @param expectedRevision - revision the caller read; `undefined` writes unconditionally.
 * @returns the namespace's redacted view after the write.
 * @throws RemoteError when the request is invalid, no provider is mounted, or the provider refuses the write.
 */
@Remote update( ns: string, patch: Record<string, JsonValue>, expectedRevision: number | undefined, ): Promise<SettingsNamespaceView>

/**
 * Replace one namespace's stored user section wholesale.
 * @param ns - namespace key to write.
 * @param section - complete replacement user section.
 * @param expectedRevision - revision the caller read; `undefined` writes unconditionally.
 * @returns the namespace's redacted view after the write.
 * @throws RemoteError when the request is invalid, no provider is mounted, or the provider refuses the write.
 */
@Remote replace( ns: string, section: Record<string, JsonValue>, expectedRevision: number | undefined, ): Promise<SettingsNamespaceView>

/**
 * Apply path-addressed edits to one namespace's user section, resolved against
 * the section as stored rather than against whatever the caller last read,
 * then answer with that namespace's new redacted view.
 * @param ns - namespace key to write.
 * @param ops - the edits to apply, in order.
 * @param expectedRevision - revision the caller read; `undefined` writes unconditionally.
 * @returns the namespace's redacted view after the write.
 * @throws RemoteError when the request is invalid, no provider is mounted, or the provider refuses the write.
 */
@Remote async mutate( ns: string, ops: SettingsPathOpView[], expectedRevision: number | undefined, ): Promise<SettingsNamespaceView>

/**
 * Materialize the provider-owned settings document and open it in a native text editor.
 * @param signal - caller lifetime; abort terminates preparation or the native command.
 * @returns confirmation after the native opener accepts the document.
 * @throws RemoteError when no document exists, preparation fails, or opening fails.
 */
@Remote async openSettingsDocument(signal: AbortSignal): Promise<SettingsDocumentOpenValue>

Source: packages/api/settings-controller/src/index.ts

settings/* events

settings/document-updated — emit

One registered namespace's RAW user section changed, whether or not the resolved value did. settings/updated is the consumer-facing event and stays deep-equal-gated; this one exists for configuration surfaces, which must learn that a field went from inherited to overridden (same resolved value, different meaning) and that their held revision is stale. Listener containment matches settings/updated.

/**
 * One registered namespace's RAW user section changed, whether or not the
 * resolved value did. `settings/updated` is the consumer-facing event and
 * stays deep-equal-gated; this one exists for configuration surfaces,
 * which must learn that a field went from inherited to overridden (same
 * resolved value, different meaning) and that their held revision is
 * stale. Listener containment matches `settings/updated`.
 * @param ns - the namespace whose stored section changed.
 * @param revision - the namespace's new revision.
 * @mode emit
 */
'settings/document-updated'(ns: SettingsNamespace, revision: number): void

Source: packages/settings/settings/src/types.ts

settings/updated — emit

Committed change to one registered namespace's resolved value. Emitted after the provider persisted (for update) or published (provider) the change; never emitted when the resolved value is deep-equal. Listener failures are contained and logged — a sync throw and an async rejection alike — except INVARIANT-coded failures, which rethrow after every listener ran; that rethrow reaches the emitter only from synchronous listeners, so invariant checks on this event must not be async functions.

/**
 * Committed change to one registered namespace's resolved value. Emitted
 * after the provider persisted (for `update`) or published (`provider`)
 * the change; never emitted when the resolved value is deep-equal.
 * Listener failures are contained and logged — a sync throw and an async
 * rejection alike — except `INVARIANT`-coded failures, which rethrow
 * after every listener ran; that rethrow reaches the emitter only from
 * synchronous listeners, so invariant checks on this event must not be
 * async functions.
 * @param ns - the namespace whose resolved value changed.
 * @param next - the new resolved value.
 * @param prev - the previous resolved value.
 * @param source - whether the change entered through `update()` or the provider.
 * @mode emit
 */
'settings/updated'(ns: SettingsNamespace, next: unknown, prev: unknown, source: SettingsUpdateSource): void

Source: packages/settings/settings/src/types.ts