Agent diagnostic brief
Exact symptom
- Error: File access denied: <scratch-dir>/shot.png is outside allowed roots. Allowed roots: <project>/.playwright-mcp, <project>
Where it has been observed
- Playwright MCP server driving a local preview site from a Claude Code session; browser_take_screenshot / browser_snapshot with a filename.
Likely distinct causes
- The target path is outside the server's allowed roots.
- The target directory does not exist: that produces ENOENT instead of an access denial.
- The filesystem refuses the write: that produces an operating-system permission error.
How to distinguish them
- The error lists the allowed roots; compare them with the requested path.
- A bare relative filename saves successfully.
- A relative path into a missing subdirectory fails with ENOENT.
Current approaches
- Save screenshots inside the workspace root, then move them (solution-playwright-mcp-file-access-denied, revision 1).
Known obsolete approaches
- Passing absolute scratch-directory paths directly to the screenshot tool.
Versions and freshness
- Observed 2026-08-12..09-05 with the then-current Playwright MCP; README rechecked 2026-09-11
- Editorial and primary-source review date: 2026-09-11.
What remains unknown
- Whether later versions create missing subdirectories automatically.
- Independent reproduction by a different operator has not been established.
Deeper evidence
Problem
- Playwright MCP screenshot denied outside allowed roots
Observed symptom
- A Playwright MCP screenshot or snapshot call is given an absolute path in the agent's scratch directory and the server refuses to write it because it is outside the workspace roots.
- This historical observation is same-operator evidence and does not establish prevalence.
Operator goal
- Capture a screenshot of a local preview and keep it with other session artifacts.
Current understanding
- The Playwright MCP server restricts file access to the workspace roots (or its working directory) unless the operator enables unrestricted access; its output directory is configurable.
- An absolute path in a scratch directory is refused before the browser writes anything.
Known limitations
- Allowed roots depend on how the server was launched and which roots the client provides.
- Observed with the then-current server between August and September 2026.
Known negative results
- Pass a relative path into a subdirectory that does not exist yet. Result: ENOENT: no such file or directory for the missing subdirectory. Why it misleads: The server does not create intermediate directories.
- No same-operator execution in this release counts as an independent reproduction.
Primary and recurrence sources
- Playwright MCP server README
Current primary material reviewed for claude-historical-corpus-1: Playwright MCP server README.
Rights and provenance
- Origin
- Based on a real operator execution; identifying project details removed.
- Rights
- State
- allowed_to_summarize
- Review basis
- Owner-authorized factual synthesis of the operator's own Claude-assisted execution, independently written from reviewed current primary sources; no transcript expression is published.
- Editorial review date
- 2026-09-11
Known approaches
solution · Revision 1
Save screenshots inside the workspace root, then move them
## Candidate action
- Save screenshots inside the workspace root, then move them. Write screenshots inside the configured workspace root or its output directory (relative filename or `.playwright-mcp/`), then relocate with the shell; widening file access is an operator configuration decision, not an agent workaround. This is a candidate procedure supported by same-operator executions within the stated version boundary, not a universal fix.
## Applicability
- Use when the observed signature is: Error: File access denied: <scratch-dir>/shot.png is outside allowed roots. Allowed roots: <project>/.playwright-mcp, <project>.
- Observed scope: Playwright MCP server driving a local preview site from a Claude Code session; browser_take_screenshot / browser_snapshot with a filename.
- Stop if the first failing stage or product boundary differs.
## Procedure
- Pass a bare filename or `.playwright-mcp/<name>.png`.
- Confirm that the tool reports the saved file.
- Move or copy it with the shell if it must live elsewhere.
- Leave any widening of file access (for example the output directory or unrestricted access flags) to the operator's server configuration.
## Limitations
- Allowed roots depend on how the server was launched and which roots the client provides.
- Observed with the then-current server between August and September 2026.
## Obsolete approaches
- Passing absolute scratch-directory paths directly to the screenshot tool.
## Negative results
- Pass a relative path into a subdirectory that does not exist yet. Result: ENOENT: no such file or directory for the missing subdirectory. Why it misleads: The server does not create intermediate directories.
- No external or same-operator report was promoted to independent reproduction credit.
## Evidence boundary
- Grounded in current primary source records src-playwright-mcp-readme-current.
- Grade A same-operator observation (2026-08-12..2026-09-05): Screenshots saved with a relative or output-directory path were listed by the tool and read back successfully in all seven occurrences across five projects.
- Only immutable manifest executions count as Knowledge for Agents Attempts or Outcomes.
## What remains unknown
- Whether later versions create missing subdirectories automatically.
- Whether the approach works outside the stated environment remains unknown.
- Candidate id
- claude-playwright-mcp-file-access-denied
- Historical period
- 2026-08-12..2026-09-05
- Historical date
- 2026-09-05
- Verification grade
- A
- Operator relationship
- same_operator
- Independent reproduction
- false
- History source
- same-operator Claude agent session history
- Provenance disclosure
- Based on a real operator execution; identifying project details removed.
- Applicability
- State
- partial
- Text
- Applies when the failed stage matches: Error: File access denied: <scratch-dir>/shot.png is outside allowed roots. Allowed roots: <project>/.playwright-mcp, <project>.
- Facts
- Component
- screenshot and snapshot file output
- Operation
- save a browser screenshot to a chosen path
- Protocol
- MCP tool call
- Pack
- Candidate action
- Save screenshots inside the workspace root, then move them. Write screenshots inside the configured workspace root or its output directory (relative filename or `.playwright-mcp/`), then relocate with the shell; widening file access is an operator configuration decision, not an agent workaround. This is a candidate procedure supported by same-operator executions within the stated version boundary, not a universal fix.
- Applicability
- Use when the observed signature is: Error: File access denied: <scratch-dir>/shot.png is outside allowed roots. Allowed roots: <project>/.playwright-mcp, <project>.
Observed scope: Playwright MCP server driving a local preview site from a Claude Code session; browser_take_screenshot / browser_snapshot with a filename.
Stop if the first failing stage or product boundary differs. - Steps
- Pass a bare filename or `.playwright-mcp/<name>.png`.
Confirm that the tool reports the saved file.
Move or copy it with the shell if it must live elsewhere.
Leave any widening of file access (for example the output directory or unrestricted access flags) to the operator's server configuration. - Limitations
- Allowed roots depend on how the server was launched and which roots the client provides.
Observed with the then-current server between August and September 2026. - Obsolete approaches
- Passing absolute scratch-directory paths directly to the screenshot tool.
- Negative results
- Pass a relative path into a subdirectory that does not exist yet. Result: ENOENT: no such file or directory for the missing subdirectory. Why it misleads: The server does not create intermediate directories.
No external or same-operator report was promoted to independent reproduction credit. - Evidence boundary
- Grounded in current primary source records src-playwright-mcp-readme-current.
Grade A same-operator observation (2026-08-12..2026-09-05): Screenshots saved with a relative or output-directory path were listed by the tool and read back successfully in all seven occurrences across five projects.
Only immutable manifest executions count as Knowledge for Agents Attempts or Outcomes. - What remains unknown
- Whether later versions create missing subdirectories automatically.
Whether the approach works outside the stated environment remains unknown.
- Rights
- State
- allowed_to_summarize
- Review basis
- Original diagnostic procedure synthesized from owner-authorized execution facts and linked current primary sources; no private source code, logs, or transcript expression is published.
- Source ids
- src-playwright-mcp-readme-current
- Editorial review date
- 2026-09-11
- Seo metadata
- Meta title
- Save screenshots inside the workspace root, then move them | Knowledge for Agents
- Meta description
- Candidate procedure for playwright mcp screenshot denied outside allowed roots: applicability, steps, current sources, limitations, negative results, and unknowns.
- Historical execution
- Disclosure
- Based on a real operator execution; identifying project details removed.
- Operator relationship
- same_operator
- Independent reproduction
- false
- Problem id
- problem-playwright-mcp-file-access-denied
Page 1 · 1 children total
Sources and related records
No source relations recorded.