Caido Mode Skill

Overview

Full-coverage CLI for Caido's API, built on the official @caido/sdk-client package. Covers:

HTTP History - Search, retrieve, replay, edit requests with HTTPQL
Replay & Sessions - Sessions, collections, entries, fuzzing
Scopes - Create and manage testing scopes (allowlist/denylist patterns)
Filter Presets - Save and reuse HTTPQL filter presets
Environments - Store test variables (victim IDs, tokens, etc.)
Findings - Create, list, update security findings
Tasks - Monitor and cancel background tasks
Projects - Switch between testing projects
Hosted Files - Manage files served by Caido
Intercept - Enable/disable request interception programmatically
Plugins - List installed plugins
Export - Convert requests to curl commands for PoCs
Health - Check Caido instance status

All traffic goes through Caido, so it appears in the UI for further analysis.

Why This Model?

Cookies and auth tokens can be huge - session cookies, JWTs, CSRF tokens can easily be 1-2KB. Rather than manually copy-pasting:

Find an organic request in Caido's HTTP history that already has valid auth
Use edit to modify just what you need (path, method, body) while keeping all auth headers intact
Send it - response comes back with full context preserved

Authentication Setup

Setup (One-Time)

Open Dashboard → Developer → Personal Access Tokens
Create a new token
Run:

node ~/.claude/skills/caido-mode/caido-client.ts setup <your-pat>

# Non-default Caido instance
node ~/.claude/skills/caido-mode/caido-client.ts setup <pat> http://192.168.1.100:8080

# Or set env var instead
export CAIDO_PAT=caido_xxxxx

The setup command validates the PAT via the SDK (which exchanges it for an access token), then saves both the PAT and the cached access token to ~/.claude/config/secrets.json. Subsequent runs load the cached token directly, skipping the PAT exchange.

Check Status

node ~/.claude/skills/caido-mode/caido-client.ts auth-status

How Auth Works

The SDK uses a device code flow internally — the PAT auto-approves it and receives an access token + refresh token. A custom SecretsTokenCache (implementing the SDK's TokenCache interface) persists these tokens to secrets.json so they survive across CLI invocations.

Auth resolution: CAIDO_PAT env var → secrets.json PAT → error with setup instructions

CLI Tool

Located at ~/.claude/skills/caido-mode/caido-client.ts. All commands output JSON.

HTTP History & Testing Commands

search - Search HTTP history with HTTPQL

node caido-client.ts search 'req.method.eq:"POST" AND resp.code.eq:200'
node caido-client.ts search 'req.host.cont:"api"' --limit 50
node caido-client.ts search 'req.path.cont:"/admin"' --ids-only
node caido-client.ts search 'resp.raw.cont:"password"' --after <cursor>

recent - Get recent requests

node caido-client.ts recent
node caido-client.ts recent --limit 50

get / get-response - Retrieve full details

node caido-client.ts get <request-id>
node caido-client.ts get <request-id> --headers-only
node caido-client.ts get-response <request-id>
node caido-client.ts get-response <request-id> --compact

edit - Edit and replay (KEY FEATURE)

Modifies an existing request while preserving all cookies/auth headers:

# Change path (IDOR testing)
node caido-client.ts edit <id> --path /api/user/999

# Change method and add body
node caido-client.ts edit <id> --method POST --body '{"admin":true}'

# Add/remove headers
node caido-client.ts edit <id> --set-header "X-Forwarded-For: 127.0.0.1"
node caido-client.ts edit <id> --remove-header "X-CSRF-Token"

# Find/replace text anywhere in request
node caido-client.ts edit <id> --replace "user123:::user456"

# Combine multiple edits
node caido-client.ts edit <id> --method PUT --path /api/admin --body '{"role":"admin"}' --compact

Option	Description
`--method <METHOD>`	Change HTTP method
`--path <path>`	Change request path
`--set-header <Name: Value>`	Add or replace a header (repeatable)
`--remove-header <Name>`	Remove a header (repeatable)
`--body <content>`	Set request body (auto-updates Content-Length)
`--replace <from>:::<to>`	Find/replace text anywhere in request (repeatable)

replay / send-raw - Send requests

# Replay as-is
node caido-client.ts replay <request-id>

# Replay with custom raw
node caido-client.ts replay <id> --raw "GET /modified HTTP/1.1\r\nHost: example.com\r\n\r\n"

# Send completely custom request
node caido-client.ts send-raw --host example.com --port 443 --tls --raw "GET / HTTP/1.1\r\nHost: example.com\r\n\r\n"

export-curl - Convert to curl for PoCs

node caido-client.ts export-curl <request-id>

Outputs a ready-to-use curl command with all headers and body.

Replay Sessions & Collections

Sessions

# Create replay session from an existing request
node caido-client.ts create-session <request-id>

# ALWAYS rename sessions for easy identification in Caido UI
node caido-client.ts rename-session <session-id> "idor-user-profile"

# List all replay sessions
node caido-client.ts replay-sessions
node caido-client.ts replay-sessions --limit 50

# Delete replay sessions
node caido-client.ts delete-sessions <session-id-1>,<session-id-2>

Collections

Organize replay sessions into collections:

# List replay collections
node caido-client.ts replay-collections
node caido-client.ts replay-collections --limit 50

# Create a collection
node caido-client.ts create-collection "IDOR Testing"

# Rename a collection
node caido-client.ts rename-collection <collection-id> "Auth Bypass Tests"

# Delete a collection
node caido-client.ts delete-collection <collection-id>

Fuzzing

# Create automate session for fuzzing
node caido-client.ts create-automate-session <request-id>

# Start fuzzing (configure payloads and markers in Caido UI first)
node caido-client.ts fuzz <session-id>

Scope Management

Define what's in scope for your testing. Uses glob patterns.

# List all scopes
node caido-client.ts scopes

# Create scope with allowlist and denylist
node caido-client.ts create-scope "Target Corp" --allow "*.target.com,*.target.io" --deny "*.cdn.target.com"

# Update scope
node caido-client.ts update-scope <scope-id> --allow "*.target.com,*.api.target.com"

# Delete scope
node caido-client.ts delete-scope <scope-id>

Glob patterns: *.example.com matches any subdomain of example.com.

Filter Presets

Save frequently used HTTPQL queries as named presets.

# List saved filters
node caido-client.ts filters

# Create filter preset
node caido-client.ts create-filter "API Errors" --query 'req.path.cont:"/api/" AND resp.code.gte:400'
node caido-client.ts create-filter "Auth Endpoints" --query 'req.path.regex:"/(login|auth|oauth)/"' --alias "auth"

# Update filter
node caido-client.ts update-filter <filter-id> --query 'req.path.cont:"/api/" AND resp.code.gte:500'

# Delete filter
node caido-client.ts delete-filter <filter-id>

Environment Variables

Store testing variables that persist across sessions. Great for IDOR testing with multiple user IDs.

# List environments
node caido-client.ts envs

# Create environment
node caido-client.ts create-env "IDOR-Test"

# Set variables
node caido-client.ts env-set <env-id> victim_user_id "user_456"
node caido-client.ts env-set <env-id> attacker_token "eyJhbG..."

# Select active environment
node caido-client.ts select-env <env-id>

# Deselect environment
node caido-client.ts select-env

# Delete environment
node caido-client.ts delete-env <env-id>

Findings

Create, list, and update security findings. Shows up in Caido's Findings tab.

# List all findings
node caido-client.ts findings
node caido-client.ts findings --limit 50

# Get a specific finding
node caido-client.ts get-finding <finding-id>

# Create finding linked to a request
node caido-client.ts create-finding <request-id> \
  --title "IDOR in user profile endpoint" \
  --description "Can access other users' profiles by changing ID parameter" \
  --reporter "rez0"

# With deduplication key (prevents duplicates)
node caido-client.ts create-finding <request-id> \
  --title "Auth bypass on /admin" \
  --dedupe-key "admin-auth-bypass"

# Update finding
node caido-client.ts update-finding <finding-id> \
  --title "Updated title" \
  --description "Updated description"

Tasks

Monitor and cancel background tasks (imports, exports, etc.).

# List all tasks
node caido-client.ts tasks

# Cancel a running task
node caido-client.ts cancel-task <task-id>

Project Management

# List all projects
node caido-client.ts projects

# Switch active project
node caido-client.ts select-project <project-id>

Hosted Files

# List hosted files
node caido-client.ts hosted-files

# Delete hosted file
node caido-client.ts delete-hosted-file <file-id>

Intercept Control

# Check intercept status
node caido-client.ts intercept-status

# Enable/disable interception
node caido-client.ts intercept-enable
node caido-client.ts intercept-disable

Info, Health & Plugins

# Current user info
node caido-client.ts viewer

# List installed plugins
node caido-client.ts plugins

# Check Caido instance health (version, ready state)
node caido-client.ts health

Output Control

Works with get, get-response, replay, edit, send-raw:

Flag	Description
`--max-body <n>`	Max response body lines (default: 200, 0=unlimited)
`--max-body-chars <n>`	Max body chars (default: 5000, 0=unlimited)
`--no-request`	Skip request raw in output
`--headers-only`	Only HTTP headers, no body
`--compact`	Shorthand: `--no-request --max-body 50 --max-body-chars 5000`

HTTPQL Reference

Caido's query language for searching HTTP history.

CRITICAL: String values MUST be quoted. Integer values are NOT quoted.

Namespaces and Fields

Namespace	Field	Type	Description
`req`	`ext`	string	File extension (includes `.`)
`req`	`host`	string	Hostname
`req`	`method`	string	HTTP method (uppercase)
`req`	`path`	string	URL path
`req`	`query`	string	Query string
`req`	`raw`	string	Full raw request
`req`	`port`	int	Port number
`req`	`len`	int	Request body length
`req`	`created_at`	date	Creation timestamp
`req`	`tls`	bool	Is HTTPS
`resp`	`raw`	string	Full raw response
`resp`	`code`	int	Status code
`resp`	`len`	int	Response body length
`resp`	`roundtrip`	int	Roundtrip time (ms)
`row`	`id`	int	Request ID
`source`	-	special	`"intercept"`, `"replay"`, `"automate"`, `"workflow"`
`preset`	-	special	Filter preset reference

Operators

String: eq, ne, cont, ncont, like, nlike, regex, nregex Integer: eq, ne, gt, gte, lt, lte Boolean: eq, ne Logical: AND, OR, parentheses for grouping

Example Queries

# POST requests with 200 responses
req.method.eq:"POST" AND resp.code.eq:200

# API requests
req.host.cont:"api" OR req.path.cont:"/api/"

# Standalone string searches both req and resp
"password" OR "secret" OR "api_key"

# Error responses
resp.code.gte:400 AND resp.code.lt:500

# Large responses (potential data exposure)
resp.len.gt:100000

# Slow endpoints
resp.roundtrip.gt:5000

# Auth endpoints by regex
req.path.regex:"/(login|auth|signin|oauth)/"

# Replay/automate traffic only
source:"replay" OR source:"automate"

# Date filtering
req.created_at.gt:"2024-01-01T00:00:00Z"

SDK Architecture

This CLI is built on @caido/sdk-client v0.1.4+, using a clean multi-file architecture:

caido-client.ts          # CLI entry point — arg parsing + command dispatch
lib/
  client.ts              # SDK Client singleton, SecretsTokenCache, auth config
  graphql.ts             # gql documents for features not yet in SDK
  output.ts              # Output formatting (truncation, headers-only, raw→curl)
  types.ts               # Shared types (OutputOpts)
  commands/
    requests.ts          # search, recent, get, get-response, export-curl
    replay.ts            # replay, send-raw, edit, sessions, collections, automate, fuzz
    findings.ts          # findings, get-finding, create-finding, update-finding
    management.ts        # scopes, filters, environments, projects, hosted-files, tasks
    intercept.ts         # intercept-status, intercept-enable, intercept-disable
    info.ts              # viewer, plugins, health, setup, auth-status

SDK Coverage

Most features use the high-level SDK directly:

SDK Method	Commands
`client.request.list()`, `.get()`	search, recent, get, get-response, export-curl
`client.replay.sessions.*`	create-session, replay-sessions, rename-session, delete-sessions
`client.replay.collections.*`	replay-collections, create-collection, rename-collection, delete-collection
`client.replay.send()`	replay, send-raw, edit
`client.finding.*`	findings, get-finding, create-finding, update-finding
`client.scope.*`	scopes, create-scope, update-scope, delete-scope
`client.filter.*`	filters, create-filter, update-filter, delete-filter
`client.environment.*`	envs, create-env, select-env, env-set, delete-env
`client.project.*`	projects, select-project
`client.hostedFile.*`	hosted-files, delete-hosted-file
`client.task.*`	tasks, cancel-task
`client.user.viewer()`	viewer
`client.health()`	health

Features not yet in the high-level SDK use client.graphql.query()/client.graphql.mutation() with gql tagged templates from graphql-tag. This is the proper SDK approach (typed documents through urql) — no raw fetch anywhere.

GraphQL Document	Commands
`INTERCEPT_OPTIONS_QUERY`	intercept-status
`PAUSE_INTERCEPT` / `RESUME_INTERCEPT`	intercept-enable, intercept-disable
`PLUGIN_PACKAGES_QUERY`	plugins
`CREATE_AUTOMATE_SESSION`	create-automate-session
`GET_AUTOMATE_SESSION`	fuzz (verify session)
`START_AUTOMATE_TASK`	fuzz (start task)

Workflow Examples

1. IDOR Testing (Primary Pattern)

# Find authenticated request
node caido-client.ts search 'req.path.cont:"/api/user"' --limit 10

# Create scope
node caido-client.ts create-scope "IDOR-Test" --allow "*.target.com"

# Create environment for test data
node caido-client.ts create-env "IDOR-Test"
node caido-client.ts env-set <env-id> victim_id "user_999"

# Test IDOR by changing user ID
node caido-client.ts edit <request-id> --path /api/user/999

# Mark as finding if it works
node caido-client.ts create-finding <request-id> --title "IDOR on /api/user/:id"

# Export curl for PoC
node caido-client.ts export-curl <request-id>

2. Privilege Escalation Testing

node caido-client.ts search 'req.path.cont:"/admin"' --limit 10
node caido-client.ts edit <id> --path /api/admin/users --method GET
node caido-client.ts edit <id> --method POST --body '{"role":"admin"}'

3. Header Bypass Testing

node caido-client.ts edit <id> --set-header "X-Forwarded-For: 127.0.0.1"
node caido-client.ts edit <id> --set-header "X-Original-URL: /admin"
node caido-client.ts edit <id> --remove-header "X-CSRF-Token"

4. Fuzzing with Automate

node caido-client.ts create-automate-session <request-id>
# Configure payload markers and wordlists in Caido UI
node caido-client.ts fuzz <session-id>

5. Filter + Analyze Pattern

# Save useful filters
node caido-client.ts create-filter "API 4xx" --query 'req.path.cont:"/api/" AND resp.code.gte:400 AND resp.code.lt:500'
node caido-client.ts create-filter "Large Responses" --query 'resp.len.gt:100000'
node caido-client.ts create-filter "Sensitive Data" --query '"password" OR "secret" OR "api_key" OR "token"'

# Quick search using preset alias
node caido-client.ts search 'preset:"API 4xx"' --limit 20

Instructions for Claude

PREFER edit OVER replay --raw - preserves cookies/auth automatically
Workflow: Search → find request with valid auth → use that ID for all tests via edit
Don't dump raw requests into context - use --compact or --headers-only when exploring
Always check auth first: health to verify connection, then recent --limit 1
ALWAYS NAME REPLAY TABS: rename-session <id> "idor-user-profile"
Create findings for anything interesting - they show up in Caido's Findings tab
Use export-curl when building PoCs for reports
Create filter presets for recurring searches to save typing
Use environments to store test data (victim IDs, tokens, etc.)
Output is JSON - parse response fields as needed

Performance & Context Optimization

search/recent omit raw field (~200 bytes per request, safe for 100+)
get fetches raw (~5-20KB per request, fetch only what you need)
Use --limit aggressively (start with 5-10)
Use --compact flag for quick exploration
Filter server-side with HTTPQL, not client-side

Error Handling

Auth errors: Run node caido-client.ts auth-status to check, re-setup with node caido-client.ts setup <pat>
Connection refused: Caido not running → node caido-client.ts health
InstanceNotReadyError: Caido is starting up, wait and retry

Related Skills

caido-plugin-dev - For building Caido plugins (backend + frontend)
spider - Crawling with Katana (uses Caido as proxy)
website-fuzzing - Remote ffuf fuzzing on hunt6
JsAnalyzer - JS analysis for traffic-discovered files