GitHub - 0hardik1/awsmux: Run one AWS CLI command across hundreds of AWS accounts in parallel. MCP built in for AI agents.

$0.193 (1.4x) 94s vs 41s

find the world-open group 50 accounts $0.229 vs $0.079 (2.9x) 75s vs 14s

find the world-open group 100 accounts $0.152 vs $0.098 (1.5x) 90s vs 17s

Full design, statistics, and caveats: docs/BENCHMARK.md. Try it on 100 accounts (none of them real) Prerequisites: Go, Docker, and the aws CLI. make build fleet-up && source .tmp/fleet/env.sh That builds ./bin/awsmux, boots a pinned LocalStack container, and provisions a fictional 100-account fleet (10 teams, prod and stage, 5 shards, 3 regions) to break for fun. The real aws CLI talks to a real emulated AWS on localhost, every profile is its own account (plus one planted admin-legacy duplicate for --dedupe to catch), and what you change actually persists. Zero credentials, zero real AWS, zero risk. ./bin/awsmux targets --profiles 'payments-*' # verified identities, per account ./bin/awsmux run --dedupe --format jsonl -- ec2 describe-vpcs --query 'Vpcs[].VpcId' # all 100 accounts in a few seconds ./bin/awsmux run --profiles '*-prod-*' -- ec2 describe-security-groups \ --filters Name=ip-permission.cidr,Values=0.0.0.0/0 # find the world-open group ./bin/awsmux plan --profiles payments-prod-1 -- ec2 revoke-security-group-ingress \ --group-name legacy-bastion --protocol tcp --port 22 --cidr 0.0.0.0/0 That last one is destructive, so it will not just run: you get an immutable plan to approve first. Apply it with the token and re-run the hunt; the finding disappears for real, because the sandbox is a real (emulated) AWS.

Try editing the plan file between approve and apply and watch the hash check refuse it. make e2e builds the binary, provisions the fleet, and smoke-tests these same beats end to end, from STS-verified discovery through the approval gate to a plan / approve / apply roundtrip and a tampered plan refused by its hash (full list in docs/ARCHITECTURE.md); make fleet-down removes the container. Real fleet Same commands, pointed at your own AWS setup instead of the sandbox environment. Zero configuration of its own: awsmux discovers profiles from your existing shared config file (~/.aws/config) and shared credentials file (~/.aws/credentials), honoring AWS_CONFIG_FILE and AWS_SHARED_CREDENTIALS_FILE. SSO, static keys, and credential_process profiles all work unchanged, because awsmux always executes through the aws CLI and verifies every identity with STS before running anything: awsmux doctor # first run? verify aws CLI, files, profiles awsmux targets --regions us-east-1,us-west-2

awsmux run --profiles 'prod-*' --exclude '*-sandbox' --format jsonl \ -- ec2 describe-instances --query 'Reservations[].Instances[].InstanceId'

awsmux plan -- ssm put-parameter --name /app/flag --value on --type String awsmux approve plan-01k... # prints a one-time token, never stored awsmux apply plan-01k... --approval-token <token> Not seeing your profiles? awsmux doctor shows exactly which files were checked, how many profiles each contributed, and whether the aws CLI and state directory are usable. awsmux targets reports where each profile came from (a SOURCE column in table mode, a source field in jsonl: config, credentials, or both).

Useful flags on run, and on apply / replay too unless noted: --concurrency (default 100: fleet-wide fan-out is the point; each in-flight target is one aws CLI subprocess), --timeout 30s, --max-errors N, --stop-on-access-denied, --output-dir (one result file per target; not on replay), --interactive (checkbox target picker; run only). Target selection (--profiles, --exclude, --regions, --preflight, --dedupe) applies to run, plan, and targets; --dedupe collapses targets that resolve to the same account, principal, and region, and it runs the STS preflight to find them even under --preflight=false. Every run lands in awsmux history and can be re-run with awsmux replay, which re-selects its targets from the stored execution. Give it to your AI agent Two commands, zero configuration: go install github.com/0hardik1/awsmux@latest claude mcp add --scope user awsmux -- awsmux mcp There is nothing to configure. awsmux mcp serves the agent interface over stdio via the Model Context Protocol: no port, no daemon, no config file, no credentials of its own. It discovers the same profiles your terminal already has (shared config and credentials files; SSO, static keys, and credential_process all pass straight through) and verifies every identity with STS before anything runs. It even locates the aws CLI in well-known install locations when an MCP client spawns it with a bare GUI PATH. Check the connection with /mcp inside Claude Code, then ask the agent "which AWS accounts can you see?" (Drop --scope user to register for the current project only. No Go toolchain? git clone + make build gives you ./bin/awsmux.)

Claude Desktop: Settings > Developer > Edit Config, then add to claude_desktop_config.json (GUI apps do not read your shell PATH, so use the absolute path from which awsmux): { "mcpServers": { "awsmux": { "command": "/absolute/path/to/awsmux", "args": ["mcp"] } } } Other MCP clients (Cursor, Windsurf, Zed, ...): same shape everywhere, a stdio server with command awsmux and args ["mcp"]. The agent gets five structured tools (list_aws_targets, plan_aws_operation, execute_aws_plan, get_aws_execution, cancel_aws_execution) instead of a raw shell, and it uses them on its own: once registered there is nothing to invoke, you just ask ("find every security group open to the world in prod") and the model reaches for the tools automatically. Read-only operations execute freely. Anything else comes back as a plan: the agent hands you a plan ID, you run awsmux approve <plan-id> in your own terminal, and you paste the one-time token back into the chat for the agent to apply. The token binds to the plan's sha256 hash, so the agent cannot alter an approved plan or execute it twice. Want to watch an agent hit the boundary with zero blast radius? Register the sandbox fleet instead: after make build fleet-up, point the server at the fleet's config via environment variables (values printed in .tmp/fleet/env.sh): claude mcp add awsmux-fleet \ --env AWS_CONFIG_FILE=$PWD/.tmp/fleet/aws-config \ --env AWS_SHARED_CREDENTIALS_FILE=$PWD/.tmp/fleet/aws-credentials \ --env AWSMUX_HOME=$PWD/.tmp/fleet/home \ -- $PWD/bin/awsmux mcp The agent gets the 100-account LocalStack fleet over MCP; let it break anything it likes. The cost and speed numbers in the table at the top come from exactly this setup. One more result from the same benchmark: when an agent was handed both a shell and the MCP tools, it picked awsmux on its own and kept nearly all of the margin.

Safety model

Class Examples Policy

read_only describe-, list-, get-*, s3 ls runs freely

mutating create-, put-, update-*, s3 cp, s3 presign --yes, interactive confirm, or approved plan

destructive delete-, terminate-, revoke-*, s3 rm, s3 mv never --yes; typed confirm or plan/approve/apply

unknown anything unrecognized treated as mutating

Where the verb convention lies, awsmux overrides it. sts calls that mint credentials (assume-role*, assume-root, get-session-token, get-federation-token), s3api operations that write a local outfile (get-object, get-object-torrent, select-object-content), and s3 presign (the URL it prints is a bearer credential for the object) are all mutating despite their read-style names, and s3 mv is destructive because it deletes the source. Where the risk lives in an argument rather than the name, the argument decides: s3 sync is mutating, but s3 sync --delete is destructive. Stable exit codes for CI and agents: 0 all succeeded, 1 some failed, 2 selection/config error, 3 approval required or rejected, 4 stopped by threshold. The 03:00 story A scanner pages: SSH is open to the world somewhere in the fleet. Your agent sweeps 14 verified accounts in one read-only call, finds sg-0a1b2c3d in payments-prod, and proposes the revoke. The revoke is destructive, so the engine hands back a plan instead of running it. You read the plan on your phone: exact command, exact account, verified principal, hash. You approve, paste one token, and go back to sleep while the fix lands in history with the hash attached. You can replay this exact story against a fleet of fakes right now: make build fleet-up.