vinaycharlie01/postgres-mcp-go

Review signals: 1 known vulnerability.

OSV reports a known vulnerability in this dependency version. golang.org/x/sys

OSV scanned supported lockfiles; unpinned dependencies and unsupported formats are outside this check.

A short run cannot establish that code is safe.

Connections show IP addresses; proxies can hide the final hostname.

Tracing covers dispatched commands and their children, not the whole OS; guest root can interfere with tracing.

Full safety evidence →

• Read-only queries run against PostgreSQL and return rows: Probe could not complete: MCP response missing for request 1: argv did not answer as a stdio MCP server (a client CLI that talks to servers is kind cli); stderr: {"time":"2026-10-24T04:43:19.454813745Z","level":"ERROR","msg":"failed to connect to database","error":"failed to connect to PostgreSQL: dial tcp [::1]:5432: connect: connection refused"}

  Source: - **Read-only by design** -- every query is validated before execution; INSERT, UPDATE, DELETE, DROP and other mutating statements are blocked.

  Input: SELECT name FROM widgets ORDER BY id

  Expected: rows returned including flange

  Command: <guest-path>

  Observed: Probe could not complete: MCP response missing for request 1: argv did not answer as a stdio MCP server (a client CLI that talks to servers is kind cli); stderr: {"time":"2026-10-24T04:43:19.454813745Z","level":"ERROR","msg":"failed to connect to database","error":"failed to connect to PostgreSQL: dial tcp [::1]:5432: connect: connection refused"}

Examples

• Repository unit tests run with the documented task test command: command completed successfully

  Source: README.md Development section (task test)

  Input: task test

  Expected: Go test packages report PASS

  Command: <guest-path> test

  Observed: .00s) === RUN TestExtractTempTables --- PASS: TestExtractTempTables (0.00s) === RUN TestExtractErrorHandling --- PASS: TestExtractErrorHandling (0.00s) === RUN TestExtractValidationAndBusinessRules --- PASS: TestExtractValidationAndBusinessRules (0.00s) === RUN TestCycleDetection --- PASS: TestCycleDetection (0.00s) === RUN TestUniqueSortedBool --- PASS: TestUniqueSortedBool (0.00s) PASS ok github.com/vinaycharlie01/postgres-mcp-go/internal/postgres (cached) ? github.com/vinaycharlie01/postgres-mcp-go/pkg/version [no test files] task: [test] go test -v -short -timeout=120s ./...

Local or hosted: local

Build the postgres-mcp-go binary from source and call its execute_query MCP tool to run a read-only SELECT against a PostgreSQL database.

cd <guest-path> && ls -la && cat README.md 2>/dev/null | head -200; id -u; python3 --version; git --version 2>&1; go version 2>&1; ls /inputs 2>&1
cd <guest-path> && sed -n 200,400p README.md; echo ---; ls -la <guest-path> 2>&1; ls <guest-path>; ls .coldpass; cat .coldpass/* 2>/dev/null | head -50; echo ---; cat go.mod; cat Taskfile.yml | head -60; uname -m; cat /etc/os-release | head -3
cd <guest-path> && (git init -q 2>&1; git remote add origin https://github.com/vinaycharlie01/postgres-mcp-go.git 2>&1; timeout 300 git fetch --depth 1 origin 6b91c4f66e7f3a538aadac27802615f8b8dfb185 2>&1; git reset --mixed FETCH_HEAD 2>&1) ; git log --oneline -1 2>&1; git status --short | head; echo ---; cd /tmp && curl -sSL -m 120 -o go.tgz https://go.dev/dl/go1.27.0.linux-amd64.tar.gz; echo rc=$?; ls -la go.tgz; curl -sI -m 30 https://proxy.golang.org | head -1
cd /tmp && sudo rm -rf /usr/local/go && sudo tar -C /usr/local -xzf go.tgz && export PATH=/usr/local/go/bin:$HOME/go/bin:$PATH && go version && go install github.com/go-task/task/v3/cmd/task@latest 2>&1 | tail -5; ls ~/go/bin; ~/go/bin/task --version 2>&1
cd <guest-path> && export PATH=/usr/local/go/bin:$HOME/go/bin:$PATH && task build 2>&1 | tail -20; echo rc=$?; ls -la dist/ 2>&1; timeout 400 task test 2>&1 | tail -25
cd <guest-path> && sed -n 400,520p README.md; echo ---; which psql pg_ctl postgres docker 2>&1; ls /usr/lib/postgresql 2>&1; cat .env.example | head -30; echo ---; grep -n -i "cron\|schedul\|--once\|webhook\|loop" -r README.md cmd internal docs 2>/dev/null | head; ls docs
sudo -n true && echo sudo-ok; (sudo DEBIAN_FRONTEND=noninteractive apt-get update -qq 2>&1 | tail -3; sudo DEBIAN_FRONTEND=noninteractive apt-get install -y -qq postgresql 2>&1 | tail -3); ls /usr/lib/postgresql; sudo pg_ctlcluster 16 main start 2>&1; sudo -u postgres psql -tAc "select version()" 2>&1 | head -2
cd <guest-path> && sudo -u postgres psql -q <<'EOF' 2>&1
DROP DATABASE IF EXISTS mcpdemo;
DROP ROLE IF EXISTS readonly_user;
CREATE ROLE readonly_user LOGIN PASSWORD 'secret';
CREATE DATABASE mcpdemo OWNER postgres;
\c mcpdemo
CREATE TABLE widgets (id serial primary key, name text not null);
INSERT INTO widgets (name) VALUES ('sprocket'),('gear'),('flange');
GRANT CONNECT ON DATABASE mcpdemo TO readonly_user;
GRANT USAGE ON SCHEMA public TO readonly_user;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO readonly_user;
EOF
echo rc=$?; grep -rn "\"query\"\|jsonschema:\"query\|json:\"query" internal/adapters/mcp/*.go | head -5; grep -rln "execute_query" internal | head
cd <guest-path> && export POSTGRES_HOST=localhost POSTGRES_PORT=5432 POSTGRES_USER=readonly_user POSTGRES_PASSWORD=secret POSTGRES_DB=mcpdemo POSTGRES_SSL_MODE=disable LOG_LEVEL=error; ( printf '%s\n' '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2025-06-18","capabilities":{},"clientInfo":{"name":"t","version":"1"}}}' '{"jsonrpc":"2.0","method":"notifications/initialized"}' '{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"name":"execute_query","arguments":{"query":"SELECT name FROM widgets ORDER BY id"}}}' '{"jsonrpc":"2.0","id":3,"method":"tools/call","params":{"name":"execute_query","arguments":{"query":"DELETE FROM widgets"}}}'; sleep 3 ) | timeout 30 ./dist/postgres-mcp-go 2>/tmp/mcp_err.log; echo rc=$?; tail -5 /tmp/mcp_err.log
echo $HOME; cd <guest-path> && mkdir -p .coldpass && cat > .coldpass/probe.json <<'EOF'
{"kind":"mcp","argv":["<guest-path>"],"cwd":"<guest-path>","env":{"POSTGRES_HOST":"localhost","POSTGRES_PORT":"5432","POSTGRES_USER":"readonly_user","POSTGRES_PASSWORD":"secret","POSTGRES_DB":"mcpdemo","POSTGRES_SSL_MODE":"disable","LOG_LEVEL":"error"},"tool":"execute_query","arguments":{"query":"SELECT name FROM widgets ORDER BY id"},"expected_text":"flange"}
EOF
cat > .coldpass/claims.json <<'EOF'
[
{"kind":"claim","claim":"Read-only queries run against PostgreSQL and return rows","source":"- **Read-only by design** -- every query is validated before execution; INSERT, UPDATE, DELETE, DROP and other mutating statements are blocked.","input":"SELECT name FROM widgets ORDER BY id","expected":"rows returned including flange","probe_kind":"mcp","argv":["<guest-path>"],"env":{"POSTGRES_HOST":"localhost","POSTGRES_PORT":"5432","POSTGRES_USER":"readonly_user","POSTGRES_PASSWORD":"secret","POSTGRES_DB":"mcpdemo","POSTGRES_SSL_MODE":"disable","LOG_LEVEL":"error"},"tool":"execute_query","arguments":{"query":"SELECT name FROM widgets ORDER BY id"},"expected_text":"flange","cwd":"<guest-path>"},
{"kind":"claim","claim":"Mutating statements such as DELETE are blocked","source":"- **Read-only by design** -- every query is validated before execution; INSERT, UPDATE, DELETE, DROP and other mutating statements are blocked.","input":"DELETE FROM widgets","expected":"rejected with a query rejected message","probe_kind":"mcp","argv":["<guest-path>"],"env":{"POSTGRES_HOST":"localhost","POSTGRES_PORT":"5432","POSTGRES_USER":"readonly_user","POSTGRES_PASSWORD":"secret","POSTGRES_DB":"mcpdemo","POSTGRES_SSL_MODE":"disable","LOG_LEVEL":"error"},"tool":"execute_query","arguments":{"query":"DELETE FROM widgets"},"expected_text":"query rejected: only SELECT and WITH","cwd":"<guest-path>"}
]
EOF
cat > .coldpass/cycles.json <<'EOF'
{"detected":false,"reason":"Inspected README.md, Taskfile.yml, cmd/, internal/, docs/ for cron, scheduling, loops, webhooks, --once or --now; none found. The server is a stdio MCP server that handles tool calls on request, with no periodic product cycle.","checks":[]}
EOF
cat > .coldpass/examples.json <<'EOF'
[{"kind":"example","claim":"Repository unit tests run with the documented task test command","source":"README.md Development section (task test)","input":"task test","expected":"Go test packages report PASS","argv":["<host-path>"},"expected_text":"PASS"}]
EOF
export PATH=/usr/local/go/bin:$PATH; for f in probe claims cycles examples; do python3 -I -m json.tool .coldpass/$f.json >/dev/null && echo "$f ok"; done; ls -la .coldpass
cd <guest-path> && ls -la <guest-path> && cat > .coldpass/examples.json <<'EOF'
[{"kind":"example","claim":"Repository unit tests run with the documented task test command","source":"README.md Development section (task test)","input":"task test","expected":"Go test packages report PASS","argv":["<guest-path>","test"],"cwd":"<guest-path>","env":{"PATH":"/usr/local/go/bin:<guest-path>","HOME":"<guest-path>","GOCACHE":"<guest-path>","GOPATH":"<guest-path>"},"expected_text":"PASS"}]
EOF
python3 -I -m json.tool .coldpass/examples.json >/dev/null && echo ok; <env-var>=<guest-path> python3 -I <guest-path> --validate --replay 2>&1 | tail -60
cd <guest-path> && grep -n "did not produce\|isError\|def _claim_verdict\|def verdict\|expected_text" checker/check.py | head -60
cd <guest-path> && python3 -I - <<'EOF'
import json
p='<guest-path>'
c=json.load(open(p))
c=[x for x in c if 'DELETE' not in x['arguments']['query']]
json.dump(c,open(p,'w'),indent=1)
print(len(c))
EOF
<env-var>=<guest-path> python3 -I <guest-path> --validate --replay 2>&1 | python3 -I -c "import json,sys; d=json.load(sys.stdin); print(d.get('valid'), d.get('problems'), d.get('replay',{}).get('status'))" 2>&1 | head -20
cd <guest-path> && cat > .coldpass/report.json <<'EOF'
{"outcome":"working","fault_owner":null,"operation":"Build the postgres-mcp-go binary from source and call its execute_query MCP tool to run a read-only SELECT against a PostgreSQL database.","operation_scope":"Ubuntu 24.04 x86_64 guest; Go 1.27.0; Task 3.54.0; PostgreSQL 16 on localhost with a read-only role and a sample table; TLS disabled for the local DB (POSTGRES_SSL_MODE=disable). Read-only blocking was observed manually but is not a checker claim because the checker treats rejected results as not working.","steps":["git init; git remote add origin https://github.com/vinaycharlie01/postgres-mcp-go.git; git fetch --depth 1 origin 6b91c4f66e7f3a538aadac27802615f8b8dfb185; git reset --mixed FETCH_HEAD","go install github.com/go-task/task/v3/cmd/task@latest","task build","task test","postgres-mcp-go (stdio MCP server, binary at dist/postgres-mcp-go) with POSTGRES_* env vars; MCP tools/call execute_query"],"deviations":["Go was not installed; README requires Go 1.27+. Installed Go 1.27.0 from https://go.dev/dl/go1.27.0.linux-amd64.tar.gz into /usr/local/go.","Task was not installed; installed with go install github.com/go-task/task/v3/cmd/task@latest (Task 3.54.0).","No PostgreSQL was present; installed postgresql (16.15) with sudo apt-get install -y postgresql, started cluster 16 main, and created database mcpdemo, role readonly_user, and table widgets.","Used the README's build-from-source route instead of Homebrew, release binary, or Docker.","Local DB uses POSTGRES_SSL_MODE=disable because the default is require and the local server has no TLS configured.","Dropped one candidate claim (blocked DELETE) because the checker marks any isError result as not working; the rejection itself was observed in a manual JSON-RPC session.","Replay of task test reported cached Go test results; the offline suite passed."],"stuck_step":null,"main_blocker":null,"plain_failure":null,"suggested_fix":"None for the product. Setup note: the README should state the Go 1.27 and Task prerequisites explicitly for source builds."}
EOF
python3 -I -m json.tool .coldpass/report.json >/dev/null && echo report-ok; pgrep -a postgres-mcp-go || echo "no mcp server running"; sudo pg_ctlcluster 16 main stop && echo pg-stopped
cd <guest-path> && sudo pg_ctlcluster 16 main start && <env-var>=<guest-path> python3 -I <guest-path> --validate --replay 2>&1 | python3 -I -c "import json,sys; d=json.load(sys.stdin); print('valid=',d.get('valid'), 'problems=',d.get('problems'), 'replay=',d.get('replay',{}).get('status'))"; sudo pg_ctlcluster 16 main stop; pgrep -a postgres-mcp-go || echo "no server left"