Consuming Web API JSON Data Using curl and jq: Complete Guide 2026

# Full production-grade GET request
curl -sS \
  -H "Authorization: Bearer $TOKEN" \
  -H "Accept: application/json" \
  -L --fail \
  "https://api.example.com/v2/users" \
  | jq

# POST with JSON body
curl -sS \
  -X POST \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{"name":"Alice","role":"admin"}' \
  "https://api.example.com/v2/users" \
  | jq

# Pretty-print (identity filter)
curl -s "https://jsonplaceholder.typicode.com/users/1" | jq '.'

# Extract a single field
curl -s "https://jsonplaceholder.typicode.com/users/1" | jq '.name'
# "Leanne Graham"

# Nested field
curl -s "https://jsonplaceholder.typicode.com/users/1" | jq '.address.city'
# "Gwenborough"

# Array element by index
curl -s "https://jsonplaceholder.typicode.com/users" | jq '.[0].name'
# "Leanne Graham"

# All elements of an array (iterator)
curl -s "https://jsonplaceholder.typicode.com/users" | jq '.[].name'
# Prints each name on a separate line

# Array length
curl -s "https://jsonplaceholder.typicode.com/users" | jq '. | length'
# 10

# Filter todos that are completed
curl -s "https://jsonplaceholder.typicode.com/todos" \
  | jq '[.[] | select(.completed == true)]'

# Filter users by userId
curl -s "https://jsonplaceholder.typicode.com/todos" \
  | jq '[.[] | select(.userId == 1)]'

# Filter posts where title contains "qui"
curl -s "https://jsonplaceholder.typicode.com/posts" \
  | jq '[.[] | select(.title | contains("qui"))]'

# Count matching items
curl -s "https://jsonplaceholder.typicode.com/todos" \
  | jq '[.[] | select(.completed == true)] | length'

# Pick specific fields (projection)
curl -s "https://jsonplaceholder.typicode.com/users" \
  | jq '[.[] | {id, name, email}]'

# Rename fields
curl -s "https://jsonplaceholder.typicode.com/users" \
  | jq '[.[] | {userId: .id, fullName: .name, contactEmail: .email}]'

# Add computed fields
curl -s "https://jsonplaceholder.typicode.com/posts" \
  | jq '[.[] | . + {titleLength: (.title | length)}]'

# Flatten nested structure
curl -s "https://jsonplaceholder.typicode.com/users" \
  | jq '[.[] | {id, name, city: .address.city, lat: .address.geo.lat}]'

# Group todos by userId
curl -s "https://jsonplaceholder.typicode.com/todos" \
  | jq 'group_by(.userId)'

# Count todos per user
curl -s "https://jsonplaceholder.typicode.com/todos" \
  | jq 'group_by(.userId) | map({userId: .[0].userId, count: length})'

# Sort posts by title length
curl -s "https://jsonplaceholder.typicode.com/posts" \
  | jq 'sort_by(.title | length)'

# Get unique userIds
curl -s "https://jsonplaceholder.typicode.com/todos" \
  | jq '[.[].userId] | unique | sort'

# Min and max
curl -s "https://jsonplaceholder.typicode.com/todos" \
  | jq 'group_by(.userId) | map({userId: .[0].userId, count: length}) | (max_by(.count), min_by(.count))'

# Print HTTP status code alongside response
curl -sS -w "\nHTTP_STATUS: %{http_code}\n" \
  "https://jsonplaceholder.typicode.com/posts/1" | jq '.'

# Store status code and body separately
HTTP_BODY=$(curl -sS -w "%{http_code}" -o /tmp/api_response.json \
  "https://api.example.com/data")
HTTP_CODE=$?
cat /tmp/api_response.json | jq '.'
echo "Status: $HTTP_BODY"

# Exit script on non-2xx (using --fail)
curl -sS --fail \
  "https://api.example.com/endpoint" \
  | jq '.' || { echo "API request failed"; exit 1; }

# Capture response headers with -D
curl -sS -D /tmp/headers.txt "https://api.example.com/data" | jq '.'
cat /tmp/headers.txt

# 1. List your GitHub repos and show name + star count
curl -sS \
  -H "Authorization: Bearer $GITHUB_TOKEN" \
  -H "Accept: application/vnd.github+json" \
  "https://api.github.com/user/repos?per_page=100" \
  | jq '[.[] | {name, stars: .stargazers_count}] | sort_by(-.stars)'

# 2. Get current temperature from OpenWeatherMap
curl -sS "https://api.openweathermap.org/data/2.5/weather?q=London&appid=$OWM_KEY&units=metric" \
  | jq '{city: .name, temp: .main.temp, feels_like: .main.feels_like, description: .weather[0].description}'

# 3. Handle paginated APIs (fetch all pages)
PAGE=1
ALL_DATA="[]"
while true; do
  RESPONSE=$(curl -sS "https://api.example.com/items?page=$PAGE&limit=100")
  ITEMS=$(echo "$RESPONSE" | jq '.items')
  COUNT=$(echo "$ITEMS" | jq 'length')

  if [ "$COUNT" -eq 0 ]; then break; fi

  ALL_DATA=$(echo "$ALL_DATA $ITEMS" | jq -s '.[0] + .[1]')
  PAGE=$((PAGE + 1))
done

echo "$ALL_DATA" | jq 'length'

# 4. Create a resource and capture the new ID
NEW_ID=$(curl -sS -X POST \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{"title":"New Post","body":"Content here","userId":1}' \
  "https://jsonplaceholder.typicode.com/posts" \
  | jq -r '.id')
echo "Created post with ID: $NEW_ID"

# 5. Use shell variables inside jq with --arg
USER_ID=3
curl -s "https://jsonplaceholder.typicode.com/posts" \
  | jq --argjson uid "$USER_ID" '[.[] | select(.userId == $uid)]'