# Using Atlas with Redis in 2026 > Redis's official MCP server lets Atlas explain why a cache hit rate collapsed, then fix the caching layer in code rather than by poking keys. Redis's official MCP server lets Atlas scan the key space, read TTLs, and explain why a cache hit rate collapsed, then fix the caching layer in code rather than by poking keys. Add it with atlas mcp add redis -- uvx --from redis-mcp-server@latest redis-mcp-server --url redis://localhost:6379/0. The server is stdio only today, so it always runs as a local process next to Atlas. ## What Atlas does with Redis's official MCP server Redis's official MCP server lets Atlas scan the key space, read TTLs, and explain why a cache hit rate collapsed. In 2026 the point of the integration is not to give the agent a Redis console, it is to let Atlas fix the caching layer in code rather than by poking keys. A collapsed cache hit rate is a code bug wearing a Redis costume. The keys are being written with a TTL that is too short, or the key format changed and the reader is looking for a name the writer no longer produces, or an invalidation fires more aggressively than anyone intended. None of those are fixed inside Redis. They are fixed in the application. What Redis's official MCP server gives Atlas is the evidence: the actual keys present, their actual TTLs, and the shape of the key space. Atlas then goes to the code where the bug lives. ## Adding Redis's official MCP server to Atlas Add Redis's official Python server with atlas mcp add redis -- uvx --from redis-mcp-server@latest redis-mcp-server --url redis://localhost:6379/0. The --from flag tells uvx which package to install and the second redis-mcp-server names the command inside it, which is a detail people miss on the first try. Redis's official server is distributed for Python, and uvx runs it without a permanent install. The command shape is slightly unusual: uvx --from redis-mcp-server@latest redis-mcp-server. The first mention is the package, the second is the executable it provides. The --url argument then takes a Redis URI, redis://localhost:6379/0 in the local case, which encodes host, port, and database index in one string. Change the host and the database index to match your deployment, and Atlas is connected. ## The Redis MCP env vars are not REDIS_URL The environment variables for Redis's official MCP server are REDIS_HOST, REDIS_PORT, REDIS_DB, REDIS_USERNAME, REDIS_PWD, and REDIS_SSL, not REDIS_URL. The URI form is only the --url flag. In 2026 this is the most common Atlas and Redis configuration mistake, because REDIS_URL is a near universal convention elsewhere. Almost every other Redis client reads REDIS_URL, so it is the first thing people set, and it does nothing here. Redis's official MCP server splits the connection into discrete variables: REDIS_HOST, REDIS_PORT, REDIS_DB, REDIS_USERNAME, REDIS_PWD, and REDIS_SSL. Note REDIS_PWD rather than the more common REDIS_PASSWORD. If you would rather express the connection as a URI, that is what the --url flag is for, and it is the only place the URI form is accepted. Pick one style and be consistent, because mixing them produces confusing failures. ## Configuring Atlas for clustered and TLS Redis Set REDIS_CLUSTER_MODE for a clustered Redis deployment and REDIS_SSL_CA_PATH when TLS is enforced. Those two environment variables are what let Atlas talk to a production Redis rather than only the local redis://localhost:6379/0 that appears in the quickstart command. The local quickstart connects to an unclustered, unencrypted Redis on the loopback, which is not what production looks like. REDIS_CLUSTER_MODE tells Redis's official MCP server that it is talking to a cluster, which changes how it routes commands across the key space. REDIS_SSL_CA_PATH points at the certificate authority bundle when TLS is enforced, alongside REDIS_SSL. Set both before you point Atlas at anything real, otherwise the connection failures will look like Redis being unreachable rather than a client that is not configured for the topology it found. ## Redis's MCP server is stdio only Redis's official MCP server is stdio only today, so it always runs as a local process next to Atlas. In 2026 there is no hosted Redis MCP endpoint to point Atlas at, which means the server has to live on a machine that can reach your Redis deployment over the network. Stdio only has a practical consequence worth planning for. Because the server runs locally alongside Atlas, the machine Atlas is running on must have network reachability to Redis, whether that is a local instance, a bastion, or a VPN. There is no remote endpoint that could reach Redis on your behalf. The upside is that the connection details, including REDIS_PWD, never leave your machine, and the security review is short: a local process, your credentials, your network path. ## The daily workflow: from a collapsed hit rate to a code fix The core Atlas and Redis loop in 2026 is a cache regression. Ask Atlas to scan the cache prefix, read the TTLs, and explain why the hit rate collapsed after the last release. Redis's official MCP server supplies the key space, and your repository supplies the release that changed it. Start with the prefix, because a scan of the whole key space on a production Redis is a bad idea and rarely necessary. Atlas scans the prefix, reads the TTLs on what it finds, and compares that reality against what the caching code in your working tree intends. Often the answer is immediate: the TTL is seconds where it should be hours, or the keys under the prefix have a new shape the reader does not match. From there, let Atlas fix the caching layer in application code and review the diff before anything touches production keys. ## Setup 1. Add Redis's official Python server with atlas mcp add redis -- uvx --from redis-mcp-server@latest redis-mcp-server --url redis://localhost:6379/0 2. Use the correct env vars: REDIS_HOST, REDIS_PORT, REDIS_DB, REDIS_USERNAME, REDIS_PWD, and REDIS_SSL, not REDIS_URL. The URI form is only the --url flag. 3. Set REDIS_CLUSTER_MODE for a clustered deployment and REDIS_SSL_CA_PATH when TLS is enforced. 4. Plan for stdio: the server is stdio only today, so it always runs as a local process next to Atlas and must be able to reach Redis over the network. 5. Ask Atlas to scan the cache prefix, read the TTLs, and explain why the hit rate collapsed after the last release. 6. Let Atlas fix the caching layer in application code and review the diff before anything touches production keys. ## FAQ ### how to connect atlas to redis Run atlas mcp add redis -- uvx --from redis-mcp-server@latest redis-mcp-server --url redis://localhost:6379/0. That registers Redis's official Python MCP server. ### why is redis_url not working with the redis mcp server Because it is not one of the supported variables. The env vars are REDIS_HOST, REDIS_PORT, REDIS_DB, REDIS_USERNAME, REDIS_PWD, and REDIS_SSL. The URI form is only the --url flag. ### how do i connect the redis mcp server to a cluster Set REDIS_CLUSTER_MODE for a clustered deployment, and set REDIS_SSL_CA_PATH when TLS is enforced on the connection. ### is there a hosted redis mcp server No. The server is stdio only today, so it always runs as a local process next to Atlas and needs network reachability to your Redis deployment. ### can atlas explain why my cache hit rate dropped Yes. Ask Atlas to scan the cache prefix, read the TTLs, and explain why the hit rate collapsed after the last release. ### what is the redis mcp password env var REDIS_PWD, not REDIS_PASSWORD. The full set is REDIS_HOST, REDIS_PORT, REDIS_DB, REDIS_USERNAME, REDIS_PWD, and REDIS_SSL. ### will atlas modify my redis keys directly The intended workflow is the opposite. Let Atlas fix the caching layer in application code and review the diff before anything touches production keys. --- Canonical HTML: https://runatlas.sh/resources/integrations/redis Source of truth: aeo_pages row `/resources/integrations/redis` (segment: Integrations) (this file is generated from it, never hand-edited). Licence: Atlas is proprietary with a free core. It is not open source and there is no public source repository.