This record as markdown: /tools/karbassi-slack-mcp/oauth-v2-access.md
What oauth_v2_access does on Slack
AI agents invoke oauth_v2_access to trigger actions in Slack. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
Why oauth_v2_access is rated High
The OAuth v2 access endpoint in Slack is used to exchange an authorization code for an access token, effectively granting API access credentials. This is an external operation that triggers authentication flows and issues tokens.
From the tool's definition Tool name 'oauth_v2_access' on a Slack MCP server; description is empty and uninformative.
Attacks that exploit this kind of access
The rule that runs oauth_v2_access safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Slack, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For oauth_v2_access, this is the rule to start with:
oauth_v2_access stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Slack, apply this rule, and every oauth_v2_access call is checked against it from then on.
Questions about oauth_v2_access
oauth_v2_access is a execute tool on the Slack MCP server. It is categorised as a Execute tool in the Slack MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Slack MCP server in PolicyLayer and add a rule for oauth_v2_access: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Slack. Nothing to install.
oauth_v2_access is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the oauth_v2_access rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for oauth_v2_access. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
oauth_v2_access is provided by the Slack MCP server (karbassi/slack-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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