Send PTY Input - Gravix Layer

POST /v1/agents/runtime/{runtime_id}/pty/{session_id}/input Writes to the session’s terminal exactly as if it had been typed.

from gravixlayer import GravixLayer

client = GravixLayer()  # defaults to cloud="aws", region="us-east-1"
sandbox = client.runtime.create()  # defaults to template="base-small"
session = sandbox.pty.create()
sid = session.session_id

# Text: a shell only acts on a line once it sees a newline.
sandbox.pty.send_input(sid, "ls -la\n")

# Bytes: control characters and escape sequences go through verbatim.
sandbox.pty.send_input(sid, b"\x03")   # Ctrl-C
sandbox.pty.send_input(sid, b"\x04")   # Ctrl-D (EOF)

sandbox.kill()

import { GravixLayer } from 'gravixlayer';

const client = new GravixLayer(); // defaults to cloud="aws", region="us-east-1"
const sandbox = await client.runtime.create(); // defaults to template="base-small"
const session = await sandbox.pty.create();
const sid = session.sessionId;

await sandbox.pty.sendInput(sid, 'ls -la\n');
await sandbox.pty.sendInput(sid, new Uint8Array([0x03])); // Ctrl-C
await sandbox.pty.sendInput(sid, new Uint8Array([0x04])); // Ctrl-D (EOF)

await sandbox.kill();

# --no-newline suppresses the trailing newline the CLI adds by default.
gravixlayer runtime pty send "$RT" "$SID" "ls -la"

gravixlayer runtime pty send "$RT" "$SID" $'\x03' --no-newline

curl -X POST "https://api.gravixlayer.ai/v1/agents/runtime/$RT/pty/$SID/input" \
  -H "Authorization: Bearer $GRAVIXLAYER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"data": "ls -la\n"}'

Parameters

Supply exactly one of the following.

Parameter	Type	Description
`data`	string	Text input, sent as UTF-8
`data_base64`	string	Base64 encoded raw bytes, for binary and control characters

The Python SDK picks the right one for you: pass str and it sends data, pass bytes and it base64 encodes into data_base64.

Response (`PtyInputResponse`)

Field	Type	Description
`success`	boolean	Whether the write was accepted
`bytes_written`	integer	Number of bytes written to the terminal

Common control characters

Bytes	Key	Effect
`\x03`	Ctrl-C	`SIGINT` to the foreground job
`\x04`	Ctrl-D	End of input; exits most shells and REPLs
`\x1a`	Ctrl-Z	`SIGTSTP`, suspends the foreground job
`\x1b`	Escape	Leaves insert mode in editors such as vim
`\t`	Tab	Shell completion

Sending \x03 writes the interrupt character to the terminal, which the guest’s line discipline turns into SIGINT for the foreground process group. This is usually what you want. Use send signal when you need to signal the session’s own process regardless of what is in the foreground.

Waiting for a prompt

Input is asynchronous: the call returns once the bytes are written, not once the program has reacted. When you need to drive a sequence of prompts, stream the output and wait for each prompt before sending the next line.

import re

pending = ["python3\n", "import sys\n", "print(sys.version)\n"]
buffer = ""

for event in sandbox.pty.stream(sid):
    if event["type"] != "data":
        continue
    buffer += event["data"].decode("utf-8", "replace")
    if pending and re.search(r"(\$|>>>) $", buffer):
        sandbox.pty.send_input(sid, pending.pop(0))
        buffer = ""
    elif not pending:
        break

const pending = ['python3\n', 'import sys\n', 'print(sys.version)\n'];
let buffer = '';

for await (const event of sandbox.pty.stream(sid)) {
  if (event.type !== 'data') continue;
  buffer += new TextDecoder().decode(event.data);
  if (pending.length > 0 && /(\$|>>>) $/.test(buffer)) {
    await sandbox.pty.sendInput(sid, pending.shift()!);
    buffer = '';
  } else if (pending.length === 0) {
    break;
  }
}