Merge Agent Handler vs One

Merge Agent Handler

Agent Handler's access keys can be limited to named users, tool packs and a runtime scope, with an expiry, and an agent can create an account with one documented request. No rate limit figures are published, Pro starts at $1,000 a month with no published overage rate, and failed or blocked calls spend credits.

One

One's remote MCP server has three tools, OAuth 2.1 sign-in with PKCE and a consent screen that sets read only, read and write, full or per-action access for each connection. A person must sign in through a browser, the SOC 2 audit is unfinished, and the site's changelog stops at 13 July 2026.

Merge Agent Handler

1. Call search_tools with a plain-language intent before tools/list. A Tool Pack can hold hundreds of tools and Slack alone lists 50
2. Add ?connectors=slack to the MCP URL to limit a connection to named connectors, and ?paginated=true only if the client follows nextCursor
3. Carry a user-scoped key with runtime:all only. The production key reaches every Registered User and the management endpoints
4. On reauth_required read data.reauth_reason, then call authenticate_<connector> by name. Intent search doesn't return the authenticate tools
5. Pin MCP-Protocol-Version to 2025-03-26 when context is tight. Later revisions repeat object results in structuredContent

One

1. Call list_one_integrations first and read each connection's access field. When the policy is actions, run those ids directly without calling find_one_actions
2. Send every operation a task needs in one find_one_actions call, up to 10 requests, each a platform and a short intent with no IDs, names or message text
3. When a document comes back as a digest, call find_one_actions again with load and a section name. Don't guess parameters the digest left out
4. After a timeout on execute_one_action, check whether the write took effect before sending it again. No idempotency key is documented
5. A 403 for a call outside the grant won't succeed on retry. Ask the user to widen the grant in the dashboard or reconnect