write

write

Type text into an input, textarea or contenteditable.

MCP tool	write
HTTP	POST /browser/write

Set submit to press Enter afterwards, which fills and submits a search box in one call. Returns the field's value read back off the element, so you can confirm the text actually landed.

Address the field with EITHER xpath OR css, never both and never neither.

To type a secret, pass secret={"name": ..., "key": ...} instead of text. list_secrets shows what there is. You never see the value: the server reads it and types it, and the result comes back with value: null. A secret may only be used on the sites its owner allowed, checked against the page you are on, so navigate there first.

Parameters

Name	Type	Required	Default	Notes
text	string	no	—
xpath	string	no	—
css	string	no	—
session_id	string	yes over HTTP	—	The session_id returned by /browser/open. Required here.
url	string	no	—
clear	boolean	no	true
submit	boolean	no	false
wait_timeout	integer	no	30
secret	SecretRef	no	—

Returns

Field	Type	Notes
value	string	The field's value read back off the element, so a caller can confirm the text landed. Null for a write whose value came from a secret — that read is not performed at all, so the credential is never returned.
text_from	string	Present only when the value came from somewhere rather than being given: the kind of source it came from, never the value.
url	string	Current URL after the action.
title	string	Page title after the action.

Errors

Status	Means
400	The request cannot succeed as sent — a missing field, a value that was rejected, or a locator that matched nothing before the wait ran out. Do not retry it unchanged.
401	Missing or wrong bearer token.
404	No such browser session. It ended, the Grid reaped it, or the id was never real. Open a new one and retry.
500	Something failed that this server did not expect.
503	The Grid could not serve this — unreachable, or no free slot for a new browser. Worth retrying after a wait.

Over MCP the same failures arrive as a tool error.

Example

MCP

write()

HTTP

curl -X POST $SELENIUM_FLOW/browser/write \
  -H "Authorization: Bearer $TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{
    "session_id": "…"
  }'

---

← All actions · Installing · Deployment