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Use settings.yaml to control what Poolside agents can do when you run pool or pool exec. For a complete reference of supported settings keys, see Settings file reference. You can use settings.yaml to:
  • Allow or block specific tools
  • Automatically approve or deny certain tool calls
  • Limit which files agents can read or modify
  • Run agents inside a local sandbox with stronger runtime boundaries
These controls help you balance productivity with safety when running agents in your development environment.

Main controls in settings.yaml

Most users interact with three configuration areas. Other supported settings include personal MCP server configuration, secret rules, prompt defaults, and API connection settings. For the full schema, see Settings file reference. These settings serve different purposes:
  • Tools decide what actions the agent can attempt.
  • Paths decide which files the agent can access through file tools.
  • Sandbox defines where the agent runs.
tools and paths mainly control approvals and explicit file operations. They do not fully sandbox the agent. If you need an enforced runtime boundary, use a sandbox.

The shell tool

Treat the shell tool as high risk. Shell commands can:
  • Install software
  • Modify files
  • Run scripts
Programs started through shell may read or modify files outside the restrictions defined in paths. If you need strict file access controls, turn off shell or run agents inside a sandbox.

File locations

Poolside reads settings.yaml from three locations. When the same setting appears in multiple files, the most specific file takes precedence:
  1. .poolside/settings.local.yaml
  2. .poolside/settings.yaml
  3. ~/.config/poolside/settings.yaml
Use ~/.config/poolside/settings.yaml for personal defaults across all projects. Use .poolside/settings.local.yaml for personal, project-specific restrictions. Use .poolside/settings.yaml for shared project defaults. For example settings files for each location, see Settings file reference.

Approvals

Approvals let you automatically allow or deny specific tool calls, which reduces repeated confirmation prompts when you trust certain operations. Rules:
  • If a tool call does not match an allow rule, Poolside asks for approval.
  • deny rules always override allow.
Approvals are a convenience feature, not a security boundary. Use a sandbox for stronger isolation.

Command-line approvals

In pool, tool calls require approval unless a matching allow rule exists in settings.yaml. To run pool exec without approval prompts, use --unsafe-auto-allow:
When --unsafe-auto-allow is set:
  • Tool calls run without prompts.
  • Deny rules still apply.
Use --unsafe-auto-allow only in trusted sandboxed environments.

Tool rules

Use tools to turn tools off or configure approval rules. File access tools such as read and edit are controlled by paths, not tools.
Add tool rules to .poolside/settings.local.yaml for personal, project-specific settings, to .poolside/settings.yaml for shared, project-specific settings, or to ~/.config/poolside/settings.yaml for personal defaults across projects.
Tools example
How tool rules work:
  • Tool rules support only * wildcards. ** is not supported.
  • The rule string must match the tool call shown in the approval prompt.
  • Subshells and composite shell commands always require manual approval.
  • Shell commands that use control operators such as | are not supported by auto-approval.

Path rules

Use paths to control which files agents can access through explicit file tools.
Add path rules to .poolside/settings.local.yaml for personal, project-specific settings, to .poolside/settings.yaml for shared, project-specific settings, or to ~/.config/poolside/settings.yaml for personal defaults across projects.
Paths example for .poolside/settings.local.yaml or ~/.config/poolside/settings.yaml
How path rules work:
  • Poolside treats paths as read-only by default.
  • write: true allows edits, deletes, moves, and renames.
  • deny overrides allow.
  • Path patterns support * and **.
  • Use forward slashes for all paths, including Windows paths.
  • Windows-volume paths do not match on Linux, and Linux paths do not match on Windows.
  • *:/Program Files/** matches any Windows volume.
  • In .poolside/settings.local.yaml and ~/.config/poolside/settings.yaml, paths must be absolute or start with ~.
  • In .poolside/settings.yaml, paths must be relative to the project.

Read-only configuration

Read-only paths example for .poolside/settings.yaml

Read-write configuration

Read-write paths example for .poolside/settings.yaml
paths rules apply only to explicit file tools. Programs started through shell may still modify files outside these rules.

Protect sensitive files across projects

To block access to sensitive files in every project, add deny rules to your personal defaults file, ~/.config/poolside/settings.yaml:
Protect sensitive files example for ~/.config/poolside/settings.yaml
deny rules always override allow.

Local sandbox

A sandbox creates a stronger runtime boundary. Sandbox workspace access supports two modes:
  • read-only: Tools can read files, and you review changes before Poolside applies them.
  • read-write: Tools can modify workspace files directly.
For user-managed local runs, define sandbox settings in your personal default ~/.config/poolside/settings.yaml file.
Sandbox example for ~/.config/poolside/settings.yaml
Sandbox configuration controls:
  • Container runtime image
  • Workspace file access
  • Extra host mounts
  • Network destinations

Use volume mounts in local sandboxes

Use volume mounts to mount extra host paths into the sandbox. If your development workflow depends on host resources outside the workspace, add extra mounts under sandbox.filesystem.mounts. For example, you can mount a persistent host cache directory, the local Docker socket, and a Docker config directory into the sandbox:
Volume mounts example for ~/.config/poolside/settings.yaml
Use this pattern when you want to reuse build artifacts and config files across sandbox recreation, talk to your local Docker daemon, or read registry credentials from a mounted config directory. Mounting /var/run/docker.sock gives processes inside the sandbox access to your host Docker daemon. Use that mount only when your workflow requires it. Best practices:
  • Use absolute host paths.
  • Put reusable build caches outside the workspace, then mount them into the sandbox.
  • Mount config directories as read-only unless the tool must write to them.
  • Do not mount a workspace directory again through mounts.
  • Choose a container image that already includes the tools your workflow needs.
Poolside already mounts workspace directories for the sandbox and rejects extra mounts that overlap with those workspace paths.

Use private or local images

For local sandboxes, Poolside uses your local Docker engine to resolve the sandbox image.
Private image example for ~/.config/poolside/settings.yaml
Before you use a private image, authenticate Docker on your host for that registry. For example:
  • Use a private image only after Docker on your machine is already authenticated to that registry.
  • You can also use an image that you built or pulled locally.

Glob reference

Tool rule syntax

Rules:
  • * matches zero or more characters including /.
  • ** is not supported.

Path rule syntax

Rules:
  • * matches characters except /.
  • ** matches across directories.
  • *:/Program Files/** matches any Windows volume.