Caido

c0tton-fluff136starsClaim this server

MCP server for Caido proxy integration. Enables AI assistants like Claude Code to browse, analyse, and interact with HTTP traffic.

Install Run on PlugMCP

GitHub

Run on PlugMCP

1# Caido

README.mdMCP server

Transport: stdio
Status: Local

Power your agent

Add this server

Install from the publisher. Not a PlugMCP endpoint.

Run on PlugMCP

Host a copy with our keys and logs.

No packaged release in the registry yet. Follow the repository README.

RepositoryPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
License: MIT
Last checked: 2026-10-28

Stars: 136
Tools: —
Uptime: —

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

How do I install Caido?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Caido need an API key?

No required environment variable is listed on this record.

What transport does Caido use?

Caido runs locally over stdio.

When was Caido last checked?

Last checked 2026-10-28. MCP server for Caido proxy integration. Enables AI assistants like Claude Code to browse, analyse, and interact with HTTP traffic.

From the publisher

Documentation

What It Does

Two ways to interact with your Caido proxy:

MCP Server - expose 67 tools and 6 read-only resources to AI assistants (Claude Code, Cursor, etc.) via the Model Context Protocol
CLI - standalone terminal client for pentesters who prefer the command line

Both share the same auth token, the same Go SDK, and the same codebase.

Features

Category	Capabilities
Proxy History	Search requests with HTTPQL, get full request/response details, diff two responses
Replay	Send HTTP requests, get response inline (status, headers, body). Per-session cookie jar auto-persists `Set-Cookie` between calls
Automate	Access fuzzing sessions, results, and payloads. Start/pause/resume/cancel tasks
Findings	Create, list, delete, and export security findings
Sitemap	Browse discovered endpoints
Scopes	Full lifecycle: create, rename, delete target scope definitions; check if a host/URL is in scope
Projects	Full lifecycle: create, rename, select, delete projects
Workflows	List, run, and toggle automation workflows
Tamper	List, create, update, toggle, and delete Match & Replace rules in all four GUI modes (update raw, update value, add, remove); dry-run a rule against a raw request before committing it
Intercept	Check status, pause/resume, list/forward/drop intercepted requests
Environments	Create, select, delete variable environments (tokens, keys)
Filters	Create, list, and delete saved HTTPQL filter presets
Hosted Files	List payload files served by Caido
Tasks	List and cancel running background tasks
Plugins	List installed plugin packages
Instance	Get Caido version and platform info

Built-in security and performance:

Credential redaction - Authorization, Cookie, and API key headers are redacted in tool output by default (including raw request/response dumps and the caido://requests/{id} resource); opt out with CAIDO_ALLOW_SENSITIVE_HEADERS (see Revealing sensitive headers)
Tool annotations - every tool declares readOnlyHint/destructiveHint/idempotentHint/openWorldHint so MCP clients can distinguish read-only, destructive, and external-network tools
Session cookie jar - RFC 6265 jar per replay session; Set-Cookie from a response is auto-attached to the next send_request against the same session
Response fingerprinting - auto-detects content kind (json/html/xml/text/binary) so agents know what they're dealing with
Adaptive body limits - JSON gets 4KB, HTML 3KB, binary 200B (override with explicit bodyLimit)
Response diff - repeated identical responses in the same session collapse to a one-line summary, saving tokens
Input validation - length limits on all string inputs to prevent context flooding
Token auto-refresh - expired OAuth tokens refresh mid-session automatically
Session reuse - single replay session per server lifetime, no sprawl

Session cookie jar

The caido_send_request tool maintains an in-memory http.CookieJar per replay session. Cookies set via Set-Cookie in any response are stored and auto-injected into subsequent requests targeting the same RFC 6265 domain/path. Pass useCookieJar: false to a single call to disable injection (useful for session-fixation testing or to verify auth gates). Use caido_clear_session_cookies to wipe a session jar between test runs and caido_get_session_cookies to introspect what is stored (cookie values are not returned, only metadata).

The output of caido_send_request includes a cookieJar block with injectedCookies (names sent on this call) and storedCookies (names captured from Set-Cookie), so the LLM can verify the chain stayed authenticated.

Response fingerprinting

Every caido_send_request / caido_batch_send response includes a compact fingerprint so an agent can reason about a response without the full body:

title - HTML <title>, if present
redirect - Location target on a 3xx
cookieNames - names set via Set-Cookie (values are never included)
wordCount - body word count, for size/diff comparison
notableHeaders - non-standard response headers (Server, X-Powered-By, custom X-*). App and flag signal often hides here - check these on every response, including 4xx/5xx.

The fingerprint stays populated even when includeBody: false.

Revealing sensitive headers

By default, sensitive headers (Authorization, Cookie, Set-Cookie, Proxy-Authorization, X-Api-Key, X-Auth-Token, X-CSRF-Token, X-XSRF-Token) are replaced with [REDACTED] in tool output to avoid leaking credentials into the model context. On an authorized engagement where you need the real values — to analyze or replay a captured authenticated request, or to produce a working caido_export_curl PoC — set CAIDO_ALLOW_SENSITIVE_HEADERS to a truthy value (1, true):

{
  "mcpServers": {
    "caido": {
      "command": "caido-mcp-server",
      "args": ["serve"],
      "env": {
        "CAIDO_URL": "http://127.0.0.1:8080",
        "CAIDO_ALLOW_SENSITIVE_HEADERS": "true"
      }
    }
  }
}

When enabled, real credential values flow through tool output to the model; leave it unset to keep redaction. This toggle does not affect the session cookie jar, which only ever reports cookie names and metadata, never values.

MCP Server

Install

curl -fsSL https://raw.githubusercontent.com/c0tton-fluff/caido-mcp-server/main/install.sh | bash

Or download a pre-built binary from Releases (macOS, Linux, Windows - amd64/arm64).

Or install with the Go toolchain (Go 1.25+):

go install github.com/c0tton-fluff/caido-mcp-server/v4/cmd/caido-mcp-server@latest

The binary lands in $(go env GOPATH)/bin (add it to your PATH). The installed binary reports its module version via caido-mcp-server --version.

git clone https://github.com/c0tton-fluff/caido-mcp-server.git
cd caido-mcp-server
go build -ldflags "-X github.com/c0tton-fluff/caido-mcp-server/v4/internal/buildinfo.version=$(git describe --tags)" -o caido-mcp-server ./cmd/caido-mcp-server

Quick Start

Option A: Static access token (recommended)

This server talks to the local Caido app's GraphQL API, which authenticates with the access token from your Caido login session — not a Caido Cloud Personal Access Token. A Cloud PAT (prefixed caido_) is for the cloud/dashboard API and will not authenticate against your local instance.

Grab the access token from the Caido GUI: open developer tools (CTRL+SHIFT+I) and run this in the Console tab:

JSON.parse(localStorage.CAIDO_AUTHENTICATION).accessToken

Pass it via the CAIDO_ACCESS_TOKEN environment variable. No login command needed.

{
  "mcpServers": {
    "caido": {
      "command": "caido-mcp-server",
      "args": ["serve"],
      "env": {
        "CAIDO_URL": "http://127.0.0.1:8080",
        "CAIDO_ACCESS_TOKEN": "your-caido-access-token"
      }
    }
  }
}

Note: this token expires after ~7 days; for a long-lived setup use Option B (OAuth), which refreshes automatically. The older CAIDO_PAT variable is still accepted as a deprecated alias for CAIDO_ACCESS_TOKEN.

Option B: OAuth device flow

CAIDO_URL=http://localhost:8080 caido-mcp-server login

This opens your browser for OAuth authentication and saves the token under ~/.caido-mcp/tokens/. Then configure your MCP client:

{
  "mcpServers": {
    "caido": {
      "command": "caido-mcp-server",
      "args": ["serve"],
      "env": {
        "CAIDO_URL": "http://127.0.0.1:8080"
      }
    }
  }
}

Credentials are stored per instance, keyed by the canonical CAIDO_URL, so you can stay logged in to several Caido instances at once and switch between them without re-authenticating. Run login once per instance. An existing ~/.caido-mcp/token.json from an earlier version is migrated automatically the first time you use it, so upgrading does not require a fresh login.

3. Use it

"List all POST requests to /api"
"Send this request with a modified user ID"
"Create a finding for this IDOR"
"Show fuzzing results from Automate session 1"
"What's in scope?"

MCP Tools (66)

Tool	Description
`caido_list_requests`	List requests with HTTPQL filter and pagination
`caido_get_request`	Get request details (metadata, headers, body). 2KB body limit default
`caido_diff_responses`	Structural diff of two responses by Caido request ID: status/size change flags and a compact body/header summary (never dumps full bodies)
`caido_send_request`	Send HTTP request via Replay, returns response inline. Polls up to 10s. Auto-injects session cookies and persists `Set-Cookie` (toggle with `useCookieJar`)
`caido_batch_send`	Send multiple requests in parallel (BAC sweeps, parameter fuzzing, endpoint sweeps). Max 50 per batch
`caido_edit_request`	Modify and resend an existing request. Preserves auth/cookies while changing method, path, headers, or body
`caido_export_curl`	Convert a request to an executable curl command for PoC reports
`caido_create_replay_session`	Create a named replay session, optionally seed with a request
`caido_list_replay_sessions`	List replay sessions
`caido_delete_replay_sessions`	Bulk delete replay sessions by ID
`caido_move_replay_session`	Move a session to a different collection
`caido_get_replay_entry`	Get replay entry with response. 2KB body limit default
`caido_clear_session_cookies`	Wipe the in-memory cookie jar for a replay session
`caido_get_session_cookies`	List metadata for cookies stored in a session jar matching a URL (values not returned)
`caido_list_replay_collections`	List replay session collections
`caido_create_replay_collection`	Create a named replay collection
`caido_rename_replay_collection`	Rename a replay collection
`caido_delete_replay_collection`	Delete a replay collection
`caido_list_automate_sessions`	List fuzzing sessions
`caido_get_automate_session`	Get session details with entry list
`caido_get_automate_entry`	Get fuzz results and payloads
`caido_automate_task_control`	Start/pause/resume/cancel fuzzing tasks
`caido_list_findings`	List security findings
`caido_create_finding`	Create finding linked to a request
`caido_delete_findings`	Delete findings by IDs or reporter name
`caido_export_findings`	Export findings for reporting
`caido_get_sitemap`	Browse sitemap hierarchy
`caido_list_scopes`	List target scopes
`caido_is_in_scope`	Check whether a host or URL is in the project scope; returns the matching scope and the allow/deny rule that decided it
`caido_create_scope`	Create new scope with allow/deny lists
`caido_rename_scope`	Rename a scope
`caido_delete_scope`	Delete a scope
`caido_list_projects`	List projects, marks current
`caido_select_project`	Switch active project
`caido_create_project`	Create a new project
`caido_rename_project`	Rename a project
`caido_delete_project`	Delete a project
`caido_list_workflows`	List automation workflows
`caido_run_workflow`	Execute an active or convert workflow
`caido_toggle_workflow`	Enable or disable a workflow
`caido_list_tamper_rules`	List Match & Replace rule collections
`caido_create_tamper_rule`	Create a tamper rule in a collection
`caido_update_tamper_rule`	Update an existing tamper rule
`caido_test_tamper_rule`	Dry-run a tamper rule against a raw request
`caido_toggle_tamper_rule`	Enable or disable a tamper rule
`caido_delete_tamper_rule`	Delete a tamper rule
`caido_get_instance`	Get Caido version and platform info
`caido_intercept_status`	Get intercept status (PAUSED/RUNNING)
`caido_intercept_control`	Pause or resume intercept
`caido_list_intercept_entries`	List queued intercept entries with HTTPQL filtering
`caido_forward_intercept`	Forward intercepted request, optionally with modifications
`caido_drop_intercept`	Drop intercepted request
`caido_list_environments`	List environments and their variables
`caido_select_environment`	Switch active environment
`caido_create_environment`	Create a new environment
`caido_delete_environment`	Delete an environment
`caido_list_filters`	List saved HTTPQL filter presets
`caido_create_filter`	Save an HTTPQL query as a named filter preset
`caido_delete_filter`	Delete a filter preset
`caido_list_hosted_files`	List hosted payload files
`caido_list_tasks`	List running background tasks
`caido_cancel_task`	Cancel a running task by ID
`caido_list_plugins`	List installed plugin packages
`caido_list_ws_streams`	List WebSocket streams (connections) from the WebSocket tab
`caido_list_ws_messages`	List WebSocket frames for a stream (direction/format/decoded body)
`caido_convert_body`	Convert a request body between JSON, form-urlencoded, XML, and multipart
`caido_race_window_send`	Fire raw HTTP/1.1 requests with synchronized last-byte send for race-condition testing (bypasses Caido proxy)

MCP Resources (6)

Read-only data exposed via the MCP resources protocol. Agents can read these without consuming tool calls.

URI	Description
`caido://requests/{id}`	Full HTTP request and response for a given request ID
`caido://replay-sessions/{id}`	Replay session details with entry list
`caido://sitemap`	Root domains from the sitemap
`caido://findings`	Security finding summaries (up to 100)
`caido://scopes`	All target scopes with their allow/deny rules
`caido://project`	Current project, instance version, and connection status

caido_list_requests

Parameter	Type	Description
`httpql`	string	HTTPQL filter query
`limit`	int	Max requests (default 20, max 100)
`after`	string	Pagination cursor

caido_get_request

Parameter	Type	Description
`ids`	string[]	Request IDs (required)
`include`	string[]	`requestHeaders`, `requestBody`, `responseHeaders`, `responseBody`
`bodyOffset`	int	Byte offset
`bodyLimit`	int	Byte limit (default 2000)

caido_send_request

Parameter	Type	Description
`raw`	string	Full HTTP request (required)
`host`	string	Target host (overrides Host header)
`port`	int	Target port
`tls`	bool	Use HTTPS (default true)
`sessionId`	string	Replay session (auto-managed if omitted)
`bodyLimit`	int	Response body byte limit (default 2000)
`bodyOffset`	int	Response body byte offset (default 0)
`useCookieJar`	bool	Auto-inject session cookies and persist `Set-Cookie` (default true); set false to disable for this call only
`includeBody`	bool	Include response body text (default true); the fingerprint is always populated
`marker`	string	String to search for in the response body; when set, `output.reflected` reports whether it was found

caido_get_replay_entry

Parameter	Type	Description
`id`	string	Replay entry ID (required)
`bodyOffset`	int	Byte offset
`bodyLimit`	int	Byte limit (default 2000)

caido_get_automate_entry

Parameter	Type	Description
`id`	string	Entry ID (required)
`limit`	int	Max results
`after`	string	Pagination cursor

caido_create_finding

Parameter	Type	Description
`requestId`	string	Associated request (required)
`title`	string	Finding title (required)
`description`	string	Finding description

caido_create_scope

Parameter	Type	Description
`name`	string	Scope name (required)
`allowlist`	string[]	Hostnames to include, e.g. `example.com`, `*.example.com` (required)
`denylist`	string[]	Hostnames to exclude

caido_select_project

Parameter	Type	Description
`id`	string	Project ID to switch to (required)

caido_intercept_control

Parameter	Type	Description
`action`	string	`pause` or `resume` (required)

caido_list_intercept_entries

Parameter	Type	Description
`filter`	string	HTTPQL filter query
`limit`	int	Max entries (default 20, max 100)
`after`	string	Pagination cursor

caido_forward_intercept

Parameter	Type	Description
`id`	string	Intercept entry ID (required)
`raw`	string	Modified raw HTTP request (base64-encoded, optional)

caido_drop_intercept

Parameter	Type	Description
`id`	string	Intercept entry ID (required)

caido_automate_task_control

Parameter	Type	Description
`action`	string	`start`, `pause`, `resume`, or `cancel` (required)
`session_id`	string	Automate session ID (required for start)
`task_id`	string	Automate task ID (required for pause/resume/cancel)

caido_delete_findings

Parameter	Type	Description
`ids`	string[]	Finding IDs to delete
`reporter`	string	Delete all findings by this reporter

caido_export_findings

Parameter	Type	Description
`ids`	string[]	Finding IDs to export
`reporter`	string	Export all findings by this reporter

caido_list_environments

No parameters required. Returns all environments with variables and selected/global context.

caido_select_environment

Parameter	Type	Description
`id`	string	Environment ID (required, empty string to deselect)

caido_run_workflow

Parameter	Type	Description
`id`	string	Workflow ID (required)
`type`	string	`active` or `convert` (required)
`request_id`	string	Request ID (required for active workflows)
`input`	string	Input data (required for convert workflows)

caido_toggle_workflow

Parameter	Type	Description
`id`	string	Workflow ID (required)
`enabled`	bool	Enable or disable (required)

caido_list_tamper_rules

No parameters required. Returns all tamper rule collections with nested rules (id, name, section, enabled, condition, sources).

caido_create_tamper_rule

Parameter	Type	Description
`collection_id`	string	Collection ID (required)
`name`	string	Rule name (required)
`section`	string	Section to match (required), see below
`operation`	object	Operation mode and parameters, see below
`match`	string	Legacy shorthand for `operation.match`
`replace`	string	Legacy shorthand for `operation.value`
`condition`	string	HTTPQL filter condition
`sources`	string[]	Traffic sources: INTERCEPT, REPLAY, AUTOMATE, IMPORT, PLUGIN, WORKFLOW, SAMPLE

Operation modes

`operation.kind`	Meaning	Fields
`updateRaw`	Pattern match over the raw section text	`match`, `match_kind`, `value`
`updateValue`	Set the value of a named header or query param	`name`, `value`
`add`	Insert a new header or query param	`name`, `value`
`remove`	Delete a named header or query param	`name`

match_kind selects how match is read: regex (default), value (literal substring, no escaping) or full (the entire section, match must be omitted). Use workflow_id instead of value to supply the replacement from a convert workflow.

All four modes are available on requestHeader, responseHeader and requestQuery. Every other section supports exactly one mode, and asking for another returns an error naming the modes it does support: requestAll, requestBody, requestFirstLine, requestPath, responseAll, responseBody, responseFirstLine take updateRaw; requestMethod, requestSNI, responseStatusCode take updateValue (they always apply, so they accept no match or name).

Omitting operation entirely falls back to the section's default mode with the legacy match/replace fields, so existing callers keep working unchanged.

caido_update_tamper_rule

Full update: pass the complete rule state, not a partial patch. Accepts the same section, operation and legacy match/replace parameters as caido_create_tamper_rule.

Parameter	Type	Description
`id`	string	Tamper rule ID (required)
`name`	string	Rule name (required)
`section`	string	Section to match (required)
`operation`	object	Operation mode and parameters
`match`	string	Legacy shorthand for `operation.match`
`replace`	string	Legacy shorthand for `operation.value`
`condition`	string	HTTPQL filter condition
`sources`	string[]	Traffic sources

caido_test_tamper_rule

Dry-run a rule against a raw HTTP request or response and return the transformed result. Nothing is persisted and no traffic is sent. Accepts the same section, operation and legacy match/replace parameters as caido_create_tamper_rule.

Parameter	Type	Description
`raw`	string	Raw HTTP request or response to transform (required)
`section`	string	Section to match (required)
`operation`	object	Operation mode and parameters

Returns raw (the transformed message) and changed (whether the rule matched anything at all), which is the quickest way to catch a rule that silently matches nothing.

caido_toggle_tamper_rule

Parameter	Type	Description
`id`	string	Tamper rule ID (required)
`enabled`	bool	Enable or disable (required)

caido_delete_tamper_rule

Parameter	Type	Description
`id`	string	Tamper rule ID (required)

CLI

Standalone terminal client for Caido. No MCP required - use it directly from your shell.

Install

curl -fsSL https://raw.githubusercontent.com/c0tton-fluff/caido-mcp-server/main/install.sh | TOOL=cli bash

Or download from Releases.

Or install with the Go toolchain (Go 1.25+):

go install github.com/c0tton-fluff/caido-mcp-server/v4/cmd/caido-cli@latest

git clone https://github.com/c0tton-fluff/caido-mcp-server.git
cd caido-mcp-server
go build -o caido-cli ./cmd/caido-cli

Usage

Requires authentication - run caido-mcp-server login first to store a token. (The CLI reads the stored login token; it does not consume the CAIDO_ACCESS_TOKEN env var that the MCP server uses.)

# Check connection and auth
caido-cli status -u http://localhost:8080

# Send structured requests
caido-cli send GET https://target.com/api/users
caido-cli send POST https://target.com/api/login -j '{"user":"admin","pass":"test"}'
caido-cli send PUT https://target.com/api/profile -H "Authorization: Bearer tok" -j '{"role":"admin"}'

# Send raw HTTP requests
caido-cli raw 'GET /api/users HTTP/1.1\r\nHost: target.com\r\n\r\n'
caido-cli raw -f request.txt --host target.com --port 8443
echo -n 'GET / HTTP/1.1\r\nHost: example.com\r\n\r\n' | caido-cli raw -

# Parallel requests via Replay (BAC sweeps, param fuzzing, endpoint sweeps)
caido-cli batch sweep https://target.com/api/profile -t "owner=eyJ1...,cross=eyJ2...,noauth"
caido-cli batch fuzz "https://target.com/api/search?q=test" -p q -v "test,test',1 OR 1=1" -H "Authorization: Bearer eyJ..."
caido-cli batch ep -t eyJ... https://target.com/dashboard https://target.com/admin
caido-cli batch file batch.json

# Browse proxy history
caido-cli history
caido-cli history -f 'req.host.eq:"target.com"' -n 20

# Get full request/response details
caido-cli request 12345

# Encode/decode
caido-cli encode base64 "hello world"
caido-cli decode url "%3Cscript%3E"
caido-cli encode hex "test"

Commands

Command	Description
`status`	Check Caido instance health and auth token
`send METHOD URL`	Send structured HTTP request via Replay API
`raw`	Send raw HTTP request (argument, file with `-f`, or stdin with `-`)
`batch MODE`	Parallel requests via Replay: `sweep` (N tokens), `fuzz` (N values), `ep` (N URLs), `file` (JSON spec)
`history`	List proxy history with HTTPQL filtering
`request ID`	Get full request/response by ID
`encode TYPE VALUE`	Encode value (`url`, `base64`, `hex`)
`decode TYPE VALUE`	Decode value (`url`, `base64`, `hex`)

Global Flags

Flag	Description
`-u, --url`	Caido instance URL (or set `CAIDO_URL`)
`-b, --body-limit`	Response body byte limit (default 2000)

Architecture

caido-mcp-server/
  cmd/
    caido-mcp-server/   MCP server (stdio transport)
    caido-cli/          Standalone CLI
  internal/
    auth/         OAuth device flow, static access token (CAIDO_ACCESS_TOKEN), token store, auto-refresh
    buildinfo/    Version resolution (ldflag or go-install module version)
    httputil/     HTTP parsing, fingerprinting, response diff, CRLF normalization
    replay/       Replay session management, cookie jar, response polling
    resources/    MCP read-only resources (requests, sessions, sitemap, findings)
    tools/        MCP tool definitions (one file per tool)
    testutil/     Mock GraphQL server, MCP test helpers, fixtures

The cmd/ directory names match the installed binary names so go install .../cmd/caido-mcp-server@latest produces a correctly-named binary. Both commands share internal/ packages. The project uses caido-community/sdk-go for all GraphQL communication with Caido.

Troubleshooting

Error	Fix
`Invalid token`	`CAIDO_ACCESS_TOKEN` must be the local Caido access token (not a Cloud PAT) — re-grab it from the GUI console, or run `caido-mcp-server login` again
`token expired, no refresh token`	The static access token expires after ~7 days; re-grab it into `CAIDO_ACCESS_TOKEN`, or use `caido-mcp-server login` (OAuth auto-refreshes)
`poll failed: timed out`	Target server slow; use `get_replay_entry` with the returned `entryId`
`no authentication token found`	Set `CAIDO_ACCESS_TOKEN` env var or run `caido-mcp-server login` before `serve`

MCP server logs: ~/.cache/claude-cli-nodejs/*/mcp-logs-caido/

Security

Sensitive HTTP headers (Authorization, Cookie, Set-Cookie, API keys) are redacted everywhere output leaves the server - structured tool output, raw request/response dumps, fuzz templates, and the caido://requests/{id} resource all pass through a single redaction choke-point to prevent credential leakage to LLM context. On an authorized engagement you can opt out with CAIDO_ALLOW_SENSITIVE_HEADERS (see Revealing sensitive headers). All string inputs are length-validated server-side, and request batch sizes are capped.

Access tokens (via CAIDO_ACCESS_TOKEN) and OAuth tokens are stored with 0600 permissions and never appear in process arguments or log output.

To report a security issue, open a GitHub issue or contact the maintainer directly.

Contributing

Fork the repo
Create a feature branch
go build ./... and go test ./... -race
Open a PR (CI runs build, test, vet, staticcheck)

Local pre-push gate

A tracked .githooks/pre-push runs the same checks as CI's lint + test jobs (gofmt, go vet, golangci-lint run ./..., go test ./... -race) so failures are caught before they reach CI. Enable it once per clone:

git config core.hooksPath .githooks
go install github.com/golangci/golangci-lint/v2/cmd/[email protected]

Built with caido-community/sdk-go and modelcontextprotocol/go-sdk.

License

MIT

Caido

c0tton-fluff136starsClaim this server

MCP server for Caido proxy integration. Enables AI assistants like Claude Code to browse, analyse, and interact with HTTP traffic.

Install Run on PlugMCP

GitHub

Run on PlugMCP

1# Caido

README.mdMCP server

Transport: stdio
Status: Local

Power your agent

Add this server

Install from the publisher. Not a PlugMCP endpoint.

Run on PlugMCP

Host a copy with our keys and logs.

No packaged release in the registry yet. Follow the repository README.

RepositoryPublisher installStep-by-step: add this in Claude

Remote URL or a command on your machine? How the two installs differ

Run on PlugMCP

Host a copy with our keys and logs.

A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.

Launch

Server facts

Local

Transport: stdio
License: MIT
Last checked: 2026-10-28

Stars: 136
Tools: —
Uptime: —

Tools

No tool list yet. Remote servers get one after the first health check.

FAQ

Questions

How do I install Caido?

Copy the stdio config for Cursor, Claude Desktop, Claude Code, or VS Code on this page. It uses the publisher's install, not a PlugMCP proxy.

Does Caido need an API key?

No required environment variable is listed on this record.

What transport does Caido use?

Caido runs locally over stdio.

When was Caido last checked?

Last checked 2026-10-28. MCP server for Caido proxy integration. Enables AI assistants like Claude Code to browse, analyse, and interact with HTTP traffic.

From the publisher

Documentation

What It Does

Two ways to interact with your Caido proxy:

MCP Server - expose 67 tools and 6 read-only resources to AI assistants (Claude Code, Cursor, etc.) via the Model Context Protocol
CLI - standalone terminal client for pentesters who prefer the command line

Both share the same auth token, the same Go SDK, and the same codebase.

Features

Category	Capabilities
Proxy History	Search requests with HTTPQL, get full request/response details, diff two responses
Replay	Send HTTP requests, get response inline (status, headers, body). Per-session cookie jar auto-persists `Set-Cookie` between calls
Automate	Access fuzzing sessions, results, and payloads. Start/pause/resume/cancel tasks
Findings	Create, list, delete, and export security findings
Sitemap	Browse discovered endpoints
Scopes	Full lifecycle: create, rename, delete target scope definitions; check if a host/URL is in scope
Projects	Full lifecycle: create, rename, select, delete projects
Workflows	List, run, and toggle automation workflows
Tamper	List, create, update, toggle, and delete Match & Replace rules in all four GUI modes (update raw, update value, add, remove); dry-run a rule against a raw request before committing it
Intercept	Check status, pause/resume, list/forward/drop intercepted requests
Environments	Create, select, delete variable environments (tokens, keys)
Filters	Create, list, and delete saved HTTPQL filter presets
Hosted Files	List payload files served by Caido
Tasks	List and cancel running background tasks
Plugins	List installed plugin packages
Instance	Get Caido version and platform info

Built-in security and performance:

Credential redaction - Authorization, Cookie, and API key headers are redacted in tool output by default (including raw request/response dumps and the caido://requests/{id} resource); opt out with CAIDO_ALLOW_SENSITIVE_HEADERS (see Revealing sensitive headers)
Tool annotations - every tool declares readOnlyHint/destructiveHint/idempotentHint/openWorldHint so MCP clients can distinguish read-only, destructive, and external-network tools
Session cookie jar - RFC 6265 jar per replay session; Set-Cookie from a response is auto-attached to the next send_request against the same session
Response fingerprinting - auto-detects content kind (json/html/xml/text/binary) so agents know what they're dealing with
Adaptive body limits - JSON gets 4KB, HTML 3KB, binary 200B (override with explicit bodyLimit)
Response diff - repeated identical responses in the same session collapse to a one-line summary, saving tokens
Input validation - length limits on all string inputs to prevent context flooding
Token auto-refresh - expired OAuth tokens refresh mid-session automatically
Session reuse - single replay session per server lifetime, no sprawl

Session cookie jar

Response fingerprinting

Every caido_send_request / caido_batch_send response includes a compact fingerprint so an agent can reason about a response without the full body:

title - HTML <title>, if present
redirect - Location target on a 3xx
cookieNames - names set via Set-Cookie (values are never included)
wordCount - body word count, for size/diff comparison
notableHeaders - non-standard response headers (Server, X-Powered-By, custom X-*). App and flag signal often hides here - check these on every response, including 4xx/5xx.

The fingerprint stays populated even when includeBody: false.

Revealing sensitive headers

{
  "mcpServers": {
    "caido": {
      "command": "caido-mcp-server",
      "args": ["serve"],
      "env": {
        "CAIDO_URL": "http://127.0.0.1:8080",
        "CAIDO_ALLOW_SENSITIVE_HEADERS": "true"
      }
    }
  }
}

MCP Server

Install

curl -fsSL https://raw.githubusercontent.com/c0tton-fluff/caido-mcp-server/main/install.sh | bash

Or download a pre-built binary from Releases (macOS, Linux, Windows - amd64/arm64).

Or install with the Go toolchain (Go 1.25+):

go install github.com/c0tton-fluff/caido-mcp-server/v4/cmd/caido-mcp-server@latest

The binary lands in $(go env GOPATH)/bin (add it to your PATH). The installed binary reports its module version via caido-mcp-server --version.

git clone https://github.com/c0tton-fluff/caido-mcp-server.git
cd caido-mcp-server
go build -ldflags "-X github.com/c0tton-fluff/caido-mcp-server/v4/internal/buildinfo.version=$(git describe --tags)" -o caido-mcp-server ./cmd/caido-mcp-server

Quick Start

Option A: Static access token (recommended)

Grab the access token from the Caido GUI: open developer tools (CTRL+SHIFT+I) and run this in the Console tab:

JSON.parse(localStorage.CAIDO_AUTHENTICATION).accessToken

Pass it via the CAIDO_ACCESS_TOKEN environment variable. No login command needed.

{
  "mcpServers": {
    "caido": {
      "command": "caido-mcp-server",
      "args": ["serve"],
      "env": {
        "CAIDO_URL": "http://127.0.0.1:8080",
        "CAIDO_ACCESS_TOKEN": "your-caido-access-token"
      }
    }
  }
}

Note: this token expires after ~7 days; for a long-lived setup use Option B (OAuth), which refreshes automatically. The older CAIDO_PAT variable is still accepted as a deprecated alias for CAIDO_ACCESS_TOKEN.

Option B: OAuth device flow

CAIDO_URL=http://localhost:8080 caido-mcp-server login

This opens your browser for OAuth authentication and saves the token under ~/.caido-mcp/tokens/. Then configure your MCP client:

{
  "mcpServers": {
    "caido": {
      "command": "caido-mcp-server",
      "args": ["serve"],
      "env": {
        "CAIDO_URL": "http://127.0.0.1:8080"
      }
    }
  }
}

3. Use it

"List all POST requests to /api"
"Send this request with a modified user ID"
"Create a finding for this IDOR"
"Show fuzzing results from Automate session 1"
"What's in scope?"

MCP Tools (66)

Tool	Description
`caido_list_requests`	List requests with HTTPQL filter and pagination
`caido_get_request`	Get request details (metadata, headers, body). 2KB body limit default
`caido_diff_responses`	Structural diff of two responses by Caido request ID: status/size change flags and a compact body/header summary (never dumps full bodies)
`caido_send_request`	Send HTTP request via Replay, returns response inline. Polls up to 10s. Auto-injects session cookies and persists `Set-Cookie` (toggle with `useCookieJar`)
`caido_batch_send`	Send multiple requests in parallel (BAC sweeps, parameter fuzzing, endpoint sweeps). Max 50 per batch
`caido_edit_request`	Modify and resend an existing request. Preserves auth/cookies while changing method, path, headers, or body
`caido_export_curl`	Convert a request to an executable curl command for PoC reports
`caido_create_replay_session`	Create a named replay session, optionally seed with a request
`caido_list_replay_sessions`	List replay sessions
`caido_delete_replay_sessions`	Bulk delete replay sessions by ID
`caido_move_replay_session`	Move a session to a different collection
`caido_get_replay_entry`	Get replay entry with response. 2KB body limit default
`caido_clear_session_cookies`	Wipe the in-memory cookie jar for a replay session
`caido_get_session_cookies`	List metadata for cookies stored in a session jar matching a URL (values not returned)
`caido_list_replay_collections`	List replay session collections
`caido_create_replay_collection`	Create a named replay collection
`caido_rename_replay_collection`	Rename a replay collection
`caido_delete_replay_collection`	Delete a replay collection
`caido_list_automate_sessions`	List fuzzing sessions
`caido_get_automate_session`	Get session details with entry list
`caido_get_automate_entry`	Get fuzz results and payloads
`caido_automate_task_control`	Start/pause/resume/cancel fuzzing tasks
`caido_list_findings`	List security findings
`caido_create_finding`	Create finding linked to a request
`caido_delete_findings`	Delete findings by IDs or reporter name
`caido_export_findings`	Export findings for reporting
`caido_get_sitemap`	Browse sitemap hierarchy
`caido_list_scopes`	List target scopes
`caido_is_in_scope`	Check whether a host or URL is in the project scope; returns the matching scope and the allow/deny rule that decided it
`caido_create_scope`	Create new scope with allow/deny lists
`caido_rename_scope`	Rename a scope
`caido_delete_scope`	Delete a scope
`caido_list_projects`	List projects, marks current
`caido_select_project`	Switch active project
`caido_create_project`	Create a new project
`caido_rename_project`	Rename a project
`caido_delete_project`	Delete a project
`caido_list_workflows`	List automation workflows
`caido_run_workflow`	Execute an active or convert workflow
`caido_toggle_workflow`	Enable or disable a workflow
`caido_list_tamper_rules`	List Match & Replace rule collections
`caido_create_tamper_rule`	Create a tamper rule in a collection
`caido_update_tamper_rule`	Update an existing tamper rule
`caido_test_tamper_rule`	Dry-run a tamper rule against a raw request
`caido_toggle_tamper_rule`	Enable or disable a tamper rule
`caido_delete_tamper_rule`	Delete a tamper rule
`caido_get_instance`	Get Caido version and platform info
`caido_intercept_status`	Get intercept status (PAUSED/RUNNING)
`caido_intercept_control`	Pause or resume intercept
`caido_list_intercept_entries`	List queued intercept entries with HTTPQL filtering
`caido_forward_intercept`	Forward intercepted request, optionally with modifications
`caido_drop_intercept`	Drop intercepted request
`caido_list_environments`	List environments and their variables
`caido_select_environment`	Switch active environment
`caido_create_environment`	Create a new environment
`caido_delete_environment`	Delete an environment
`caido_list_filters`	List saved HTTPQL filter presets
`caido_create_filter`	Save an HTTPQL query as a named filter preset
`caido_delete_filter`	Delete a filter preset
`caido_list_hosted_files`	List hosted payload files
`caido_list_tasks`	List running background tasks
`caido_cancel_task`	Cancel a running task by ID
`caido_list_plugins`	List installed plugin packages
`caido_list_ws_streams`	List WebSocket streams (connections) from the WebSocket tab
`caido_list_ws_messages`	List WebSocket frames for a stream (direction/format/decoded body)
`caido_convert_body`	Convert a request body between JSON, form-urlencoded, XML, and multipart
`caido_race_window_send`	Fire raw HTTP/1.1 requests with synchronized last-byte send for race-condition testing (bypasses Caido proxy)

MCP Resources (6)

Read-only data exposed via the MCP resources protocol. Agents can read these without consuming tool calls.

URI	Description
`caido://requests/{id}`	Full HTTP request and response for a given request ID
`caido://replay-sessions/{id}`	Replay session details with entry list
`caido://sitemap`	Root domains from the sitemap
`caido://findings`	Security finding summaries (up to 100)
`caido://scopes`	All target scopes with their allow/deny rules
`caido://project`	Current project, instance version, and connection status

caido_list_requests

Parameter	Type	Description
`httpql`	string	HTTPQL filter query
`limit`	int	Max requests (default 20, max 100)
`after`	string	Pagination cursor

caido_get_request

Parameter	Type	Description
`ids`	string[]	Request IDs (required)
`include`	string[]	`requestHeaders`, `requestBody`, `responseHeaders`, `responseBody`
`bodyOffset`	int	Byte offset
`bodyLimit`	int	Byte limit (default 2000)

caido_send_request

Parameter	Type	Description
`raw`	string	Full HTTP request (required)
`host`	string	Target host (overrides Host header)
`port`	int	Target port
`tls`	bool	Use HTTPS (default true)
`sessionId`	string	Replay session (auto-managed if omitted)
`bodyLimit`	int	Response body byte limit (default 2000)
`bodyOffset`	int	Response body byte offset (default 0)
`useCookieJar`	bool	Auto-inject session cookies and persist `Set-Cookie` (default true); set false to disable for this call only
`includeBody`	bool	Include response body text (default true); the fingerprint is always populated
`marker`	string	String to search for in the response body; when set, `output.reflected` reports whether it was found

caido_get_replay_entry

Parameter	Type	Description
`id`	string	Replay entry ID (required)
`bodyOffset`	int	Byte offset
`bodyLimit`	int	Byte limit (default 2000)

caido_get_automate_entry

Parameter	Type	Description
`id`	string	Entry ID (required)
`limit`	int	Max results
`after`	string	Pagination cursor

caido_create_finding

Parameter	Type	Description
`requestId`	string	Associated request (required)
`title`	string	Finding title (required)
`description`	string	Finding description

caido_create_scope

Parameter	Type	Description
`name`	string	Scope name (required)
`allowlist`	string[]	Hostnames to include, e.g. `example.com`, `*.example.com` (required)
`denylist`	string[]	Hostnames to exclude

caido_select_project

Parameter	Type	Description
`id`	string	Project ID to switch to (required)

caido_intercept_control

Parameter	Type	Description
`action`	string	`pause` or `resume` (required)

caido_list_intercept_entries

Parameter	Type	Description
`filter`	string	HTTPQL filter query
`limit`	int	Max entries (default 20, max 100)
`after`	string	Pagination cursor

caido_forward_intercept

Parameter	Type	Description
`id`	string	Intercept entry ID (required)
`raw`	string	Modified raw HTTP request (base64-encoded, optional)

caido_drop_intercept

Parameter	Type	Description
`id`	string	Intercept entry ID (required)

caido_automate_task_control

Parameter	Type	Description
`action`	string	`start`, `pause`, `resume`, or `cancel` (required)
`session_id`	string	Automate session ID (required for start)
`task_id`	string	Automate task ID (required for pause/resume/cancel)

caido_delete_findings

Parameter	Type	Description
`ids`	string[]	Finding IDs to delete
`reporter`	string	Delete all findings by this reporter

caido_export_findings

Parameter	Type	Description
`ids`	string[]	Finding IDs to export
`reporter`	string	Export all findings by this reporter

caido_list_environments

No parameters required. Returns all environments with variables and selected/global context.

caido_select_environment

Parameter	Type	Description
`id`	string	Environment ID (required, empty string to deselect)

caido_run_workflow

Parameter	Type	Description
`id`	string	Workflow ID (required)
`type`	string	`active` or `convert` (required)
`request_id`	string	Request ID (required for active workflows)
`input`	string	Input data (required for convert workflows)

caido_toggle_workflow

Parameter	Type	Description
`id`	string	Workflow ID (required)
`enabled`	bool	Enable or disable (required)

caido_list_tamper_rules

No parameters required. Returns all tamper rule collections with nested rules (id, name, section, enabled, condition, sources).

caido_create_tamper_rule

Parameter	Type	Description
`collection_id`	string	Collection ID (required)
`name`	string	Rule name (required)
`section`	string	Section to match (required), see below
`operation`	object	Operation mode and parameters, see below
`match`	string	Legacy shorthand for `operation.match`
`replace`	string	Legacy shorthand for `operation.value`
`condition`	string	HTTPQL filter condition
`sources`	string[]	Traffic sources: INTERCEPT, REPLAY, AUTOMATE, IMPORT, PLUGIN, WORKFLOW, SAMPLE

Operation modes

`operation.kind`	Meaning	Fields
`updateRaw`	Pattern match over the raw section text	`match`, `match_kind`, `value`
`updateValue`	Set the value of a named header or query param	`name`, `value`
`add`	Insert a new header or query param	`name`, `value`
`remove`	Delete a named header or query param	`name`

Omitting operation entirely falls back to the section's default mode with the legacy match/replace fields, so existing callers keep working unchanged.

caido_update_tamper_rule

Full update: pass the complete rule state, not a partial patch. Accepts the same section, operation and legacy match/replace parameters as caido_create_tamper_rule.

Parameter	Type	Description
`id`	string	Tamper rule ID (required)
`name`	string	Rule name (required)
`section`	string	Section to match (required)
`operation`	object	Operation mode and parameters
`match`	string	Legacy shorthand for `operation.match`
`replace`	string	Legacy shorthand for `operation.value`
`condition`	string	HTTPQL filter condition
`sources`	string[]	Traffic sources

caido_test_tamper_rule

Parameter	Type	Description
`raw`	string	Raw HTTP request or response to transform (required)
`section`	string	Section to match (required)
`operation`	object	Operation mode and parameters

Returns raw (the transformed message) and changed (whether the rule matched anything at all), which is the quickest way to catch a rule that silently matches nothing.

caido_toggle_tamper_rule

Parameter	Type	Description
`id`	string	Tamper rule ID (required)
`enabled`	bool	Enable or disable (required)

caido_delete_tamper_rule

Parameter	Type	Description
`id`	string	Tamper rule ID (required)

CLI

Standalone terminal client for Caido. No MCP required - use it directly from your shell.

Install

curl -fsSL https://raw.githubusercontent.com/c0tton-fluff/caido-mcp-server/main/install.sh | TOOL=cli bash

Or download from Releases.

Or install with the Go toolchain (Go 1.25+):

go install github.com/c0tton-fluff/caido-mcp-server/v4/cmd/caido-cli@latest

git clone https://github.com/c0tton-fluff/caido-mcp-server.git
cd caido-mcp-server
go build -o caido-cli ./cmd/caido-cli

Usage

Requires authentication - run caido-mcp-server login first to store a token. (The CLI reads the stored login token; it does not consume the CAIDO_ACCESS_TOKEN env var that the MCP server uses.)

# Check connection and auth
caido-cli status -u http://localhost:8080

# Send structured requests
caido-cli send GET https://target.com/api/users
caido-cli send POST https://target.com/api/login -j '{"user":"admin","pass":"test"}'
caido-cli send PUT https://target.com/api/profile -H "Authorization: Bearer tok" -j '{"role":"admin"}'

# Send raw HTTP requests
caido-cli raw 'GET /api/users HTTP/1.1\r\nHost: target.com\r\n\r\n'
caido-cli raw -f request.txt --host target.com --port 8443
echo -n 'GET / HTTP/1.1\r\nHost: example.com\r\n\r\n' | caido-cli raw -

# Parallel requests via Replay (BAC sweeps, param fuzzing, endpoint sweeps)
caido-cli batch sweep https://target.com/api/profile -t "owner=eyJ1...,cross=eyJ2...,noauth"
caido-cli batch fuzz "https://target.com/api/search?q=test" -p q -v "test,test',1 OR 1=1" -H "Authorization: Bearer eyJ..."
caido-cli batch ep -t eyJ... https://target.com/dashboard https://target.com/admin
caido-cli batch file batch.json

# Browse proxy history
caido-cli history
caido-cli history -f 'req.host.eq:"target.com"' -n 20

# Get full request/response details
caido-cli request 12345

# Encode/decode
caido-cli encode base64 "hello world"
caido-cli decode url "%3Cscript%3E"
caido-cli encode hex "test"

Commands

Command	Description
`status`	Check Caido instance health and auth token
`send METHOD URL`	Send structured HTTP request via Replay API
`raw`	Send raw HTTP request (argument, file with `-f`, or stdin with `-`)
`batch MODE`	Parallel requests via Replay: `sweep` (N tokens), `fuzz` (N values), `ep` (N URLs), `file` (JSON spec)
`history`	List proxy history with HTTPQL filtering
`request ID`	Get full request/response by ID
`encode TYPE VALUE`	Encode value (`url`, `base64`, `hex`)
`decode TYPE VALUE`	Decode value (`url`, `base64`, `hex`)

Global Flags

Flag	Description
`-u, --url`	Caido instance URL (or set `CAIDO_URL`)
`-b, --body-limit`	Response body byte limit (default 2000)

Architecture

caido-mcp-server/
  cmd/
    caido-mcp-server/   MCP server (stdio transport)
    caido-cli/          Standalone CLI
  internal/
    auth/         OAuth device flow, static access token (CAIDO_ACCESS_TOKEN), token store, auto-refresh
    buildinfo/    Version resolution (ldflag or go-install module version)
    httputil/     HTTP parsing, fingerprinting, response diff, CRLF normalization
    replay/       Replay session management, cookie jar, response polling
    resources/    MCP read-only resources (requests, sessions, sitemap, findings)
    tools/        MCP tool definitions (one file per tool)
    testutil/     Mock GraphQL server, MCP test helpers, fixtures

Troubleshooting

Error	Fix
`Invalid token`	`CAIDO_ACCESS_TOKEN` must be the local Caido access token (not a Cloud PAT) — re-grab it from the GUI console, or run `caido-mcp-server login` again
`token expired, no refresh token`	The static access token expires after ~7 days; re-grab it into `CAIDO_ACCESS_TOKEN`, or use `caido-mcp-server login` (OAuth auto-refreshes)
`poll failed: timed out`	Target server slow; use `get_replay_entry` with the returned `entryId`
`no authentication token found`	Set `CAIDO_ACCESS_TOKEN` env var or run `caido-mcp-server login` before `serve`

MCP server logs: ~/.cache/claude-cli-nodejs/*/mcp-logs-caido/

Security

Access tokens (via CAIDO_ACCESS_TOKEN) and OAuth tokens are stored with 0600 permissions and never appear in process arguments or log output.

To report a security issue, open a GitHub issue or contact the maintainer directly.

Contributing

Fork the repo
Create a feature branch
go build ./... and go test ./... -race
Open a PR (CI runs build, test, vet, staticcheck)

Local pre-push gate

git config core.hooksPath .githooks
go install github.com/golangci/golangci-lint/v2/cmd/[email protected]

Built with caido-community/sdk-go and modelcontextprotocol/go-sdk.

License

MIT