--- title: ExecProcess description: "A long-running exec as the AI SDK's SandboxProcess shape." --- A long-running exec as the AI SDK's `SandboxProcess` shape. See the module docs. Built by `Session.spawn`, never by a constructor: a process object with no exec behind it is one whose every method fails in a way that looks like a dead VM. ## Accessors ### execId #### Get Signature ```ts get execId(): string; ``` The exec id, which is the idempotency key. Read it back to reattach from another process: `session.exec(id)` addresses the same server-side exec, and `session.spawn` with the same id does not start a second child. ##### Returns `string` *** ### gaps #### Get Signature ```ts get gaps(): OutputGap[]; ``` Every byte range the daemon could not replay, under `gapPolicy: 'event'`. Empty under the default policy, where a gap errors the streams instead — see the module docs for why the ignorable form is not the default. ##### Returns [`OutputGap`](/microvms-agentd/reference/typescript/interfaces/outputgap/)\[] *** ### pid #### Get Signature ```ts get pid(): number | null; ``` The process id, if the sandbox exposes one. **Always `null`**, and that is a true answer rather than a stub. The daemon signals a whole process group and addresses an exec by its caller-minted id; it publishes no pid, because a pid inside a MicroVM is not meaningful outside it and would invite a caller to signal it directly through a channel that does not exist. The harness contract marks `pid` optional for exactly this case. ##### Returns `number` | `null` *** ### stderr #### Get Signature ```ts get stderr(): ReadableStream>; ``` The child's standard error as a stream of bytes. Independent of \[`Self::stdout`]: order is preserved within each and is not recoverable between them, which is what the wire supports (one shared offset space) and what the harness shape promises. ##### Returns `ReadableStream`\<`Uint8Array`\<`ArrayBufferLike`>> *** ### stdout #### Get Signature ```ts get stdout(): ReadableStream>; ``` The child's standard output as a stream of bytes. One stream per process: reading this twice hands back the same object, because two readers over one channel would split the bytes between them. ##### Returns `ReadableStream`\<`Uint8Array`\<`ArrayBufferLike`>> ## Methods ### kill() ```ts kill(): Promise; ``` Terminates the process. Idempotent. Signals the whole process group rather than the direct child, so a shell's children go with it. Idempotent because the daemon answers 200 either way: a group that had already been reaped reports nothing signalled, which is the outcome a kill wanted — so a second call is a success and not a 404. That is what lets a harness call this in a `finally` without guarding it. #### Returns `Promise`\<`void`> *** ### wait() ```ts wait(timeoutSeconds?: number | null): Promise; ``` Resolves when the process exits. **From the daemon's exec record, not from the streams ending**, and that is the whole reason a suspend/resume does not look like a clean exit here: a stream that stopped carrying bytes is a stream that stopped, which is the identical observation for a cut connection and a finished command. Only the daemon's record distinguishes them. Rejects with `ERR_TIMEOUT` past `timeoutSeconds` (300 by default). A timeout has not touched the exec — polling is read-only and the output lives until it is acked — so a caller that gives up can call this again. #### Parameters | Parameter | Type | | ------ | ------ | | `timeoutSeconds?` | `number` | `null` | #### Returns `Promise`\<[`ProcessExit`](/microvms-agentd/reference/typescript/interfaces/processexit/)> ## Provenance This page is generated from `bindings/microvms-js/index.d.ts` by TypeDoc 0.28.20 and typedoc-plugin-markdown 4.13.1, run from `site/scripts/gen-reference.mjs` on every `pnpm run sync`, so an edit made here is overwritten by the next run. To change the page, change the doc comment in the binding's Rust source, then regenerate the declarations with `mise run dts`. `mise run dts:check` fails when the committed file no longer matches the source.