oassis — web scraping, crawling and browser control for AI agents

web_crawl

Read-only

Follows a site's links and reads every page. Returns a jobId; poll it with web_crawl_status. API key and credits required; limit controls the maximum pages charged. Use web_map first if you only need the urls. Reference for the oassis API: https://oassis.dev/openapi.json

Input Schema

TableJSON Schema

Name	Required	Description	Default
`url`	Yes	Page to process.
`json`	No	For the `json` format: a `prompt` describing what to pull out, a JSON `schema` to fill, or both.
`wait`	No	When to consider the page loaded: `until` (load, domcontentloaded, networkidle0, networkidle2), `selector` to wait for, `timeout` in ms.
`block`	No	What not to load, which makes a render faster and cheaper. `resourceTypes` takes image, font, stylesheet, media… and `urlPatterns` are regular expressions, not globs: `\.svg$`, not `*.svg`.
`limit`	No	Pages this crawl may read, up to 200. Charged up front; what it does not read comes back.
`links`	No	Options for the `links` format: `visibleOnly`, `excludeExternal` to keep only internal links.
`maxAge`	No	Accept an answer up to this many milliseconds old. A cache hit costs $0.0002 instead of the format price. Leave it out to force a fresh render.
`formats`	No	Outputs you want in the same response. `controls` is the map of what can be clicked; `elements` needs `selectors`; `json` needs `json.prompt` or `json.schema`. A screenshot or a PDF is not available here: every result is kept until you collect it. Ask for those one url at a time on web_scrape.
`request`	No	How to make the request: `headers`, `cookies`, `userAgent`, and `auth` for basic authentication.
`binaryAs`	No	How a screenshot or a PDF comes back. `base64` is the only value today.	base64
`controls`	No	Options for the `controls` format: `visibleOnly`, and `limit` (1 to 1000) to cut the map.
`maxDepth`	No	How far from the starting page to follow links. 0 reads only the starting page.
`viewport`	No	The window to render in: `width`, `height`, `deviceScaleFactor`.
`selectors`	No	CSS selectors for the `elements` format.
`excludePaths`	No	Discard urls whose path contains one of these. Up to twenty. It wins over `includePaths`.
`includePaths`	No	Keep only urls whose path contains one of these. Up to twenty.
`includeSubdomains`	No	Treat subdomains of the same site as part of it.

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedOct 19, 2026
- changedInput schema / properties / binaryAs / enum
```
Previous value: -[
-  "base64",
-  "url"
-]New value: +[
+  "base64"
+]
```
- removedInput schema / properties / json / properties / model
```
Removed value: -{
-  "minLength": 1,
-  "type": "string"
-}
```

Changed33 schema fields changedOct 4, 2026

addedInput schema / properties / binaryAs

Added value: +{
+  "default": "base64",
+  "description": "How a screenshot or a PDF comes back. `base64` is the only value today.",
+  "enum": [
+    "base64",
+    "url"
+  ],
+  "type": "string"
+}

addedInput schema / properties / block

Added value: +{
+  "additionalProperties": false,
+  "description": "What not to load, which makes a render faster and cheaper. `resourceTypes` takes image, font, stylesheet, media… and `urlPatterns` are regular expressions, not globs: `\\.svg$`, not `*.svg`.",
+  "properties": {
+    "resourceTypes": {
+      "items": {
+        "minLength": 1,
+        "type": "string"
+      },
+      "type": "array"
+    },
+    "urlPatterns": {
+      "items": {
+        "minLength": 1,
+        "type": "string"
+      },
+      "type": "array"
+    }
+  },
+  "type": "object"
+}

addedInput schema / properties / controls

Added value: +{
+  "additionalProperties": false,
+  "description": "Options for the `controls` format: `visibleOnly`, and `limit` (1 to 1000) to cut the map.",
+  "properties": {
+    "limit": {
+      "maximum": 1000,
+      "minimum": 1,
+      "type": "integer"
+    },
+    "visibleOnly": {
+      "type": "boolean"
+    }
+  },
+  "type": "object"
+}

addedInput schema / properties / excludePaths / description

Added value: +"Discard urls whose path contains one of these. Up to twenty. It wins over `includePaths`."

addedInput schema / properties / excludePaths / items / minLength
```
Added value: +1
```
addedInput schema / properties / excludePaths / maxItems
```
Added value: +20
```

changedInput schema / properties / formats / description

Previous value: -"Outputs you want in the same response. `controls` is the map of what can be clicked; `elements` needs `selectors`; `json` needs `json.prompt`."New value: +"Outputs you want in the same response. `controls` is the map of what can be clicked; `elements` needs `selectors`; `json` needs `json.prompt` or `json.schema`. A screenshot or a PDF is not available here: every result is kept until you collect it. Ask for those one url at a time on web_scrape."

changedInput schema / properties / formats / items / enum

Previous value: -[
-  "html",
-  "markdown",
-  "links",
-  "screenshot",
-  "pdf",
-  "elements",
-  "json",
-  "accessibility",
-  "controls"
-]New value: +[
+  "html",
+  "markdown",
+  "links",
+  "elements",
+  "json",
+  "accessibility",
+  "controls"
+]

addedInput schema / properties / includePaths / description

Added value: +"Keep only urls whose path contains one of these. Up to twenty."

addedInput schema / properties / includePaths / items / minLength
```
Added value: +1
```
addedInput schema / properties / includePaths / maxItems
```
Added value: +20
```

addedInput schema / properties / includeSubdomains / description

Added value: +"Treat subdomains of the same site as part of it."

addedInput schema / properties / json

Added value: +{
+  "additionalProperties": false,
+  "description": "For the `json` format: a `prompt` describing what to pull out, a JSON `schema` to fill, or both.",
+  "properties": {
+    "model": {
+      "minLength": 1,
+      "type": "string"
+    },
+    "prompt": {
+      "minLength": 1,
+      "type": "string"
+    },
+    "schema": {
+      "additionalProperties": {},
+      "type": "object"
+    }
+  },
+  "type": "object"
+}

addedInput schema / properties / limit / default
```
Added value: +25
```

changedInput schema / properties / limit / description

Previous value: -"Pages it may read (default 25, max 200)."New value: +"Pages this crawl may read, up to 200. Charged up front; what it does not read comes back."

addedInput schema / properties / limit / maximum
```
Added value: +200
```
addedInput schema / properties / limit / minimum
```
Added value: +1
```

changedInput schema / properties / limit / type

Previous value: -"number"New value: +"integer"

addedInput schema / properties / links

Added value: +{
+  "additionalProperties": false,
+  "description": "Options for the `links` format: `visibleOnly`, `excludeExternal` to keep only internal links.",
+  "properties": {
+    "excludeExternal": {
+      "type": "boolean"
+    },
+    "visibleOnly": {
+      "type": "boolean"
+    }
+  },
+  "type": "object"
+}

addedInput schema / properties / maxAge / maximum
```
Added value: +604800000
```
addedInput schema / properties / maxAge / minimum
```
Added value: +0
```

changedInput schema / properties / maxAge / type

Previous value: -"number"New value: +"integer"

addedInput schema / properties / maxDepth / default
```
Added value: +2
```

changedInput schema / properties / maxDepth / description

Previous value: -"How far to follow links (default 2, max 5)."New value: +"How far from the starting page to follow links. 0 reads only the starting page."

addedInput schema / properties / maxDepth / maximum
```
Added value: +5
```
addedInput schema / properties / maxDepth / minimum
```
Added value: +0
```

changedInput schema / properties / maxDepth / type

Previous value: -"number"New value: +"integer"

addedInput schema / properties / request

Added value: +{
+  "additionalProperties": false,
+  "description": "How to make the request: `headers`, `cookies`, `userAgent`, and `auth` for basic authentication.",
+  "properties": {
+    "auth": {
+      "additionalProperties": false,
+      "properties": {
+        "password": {
+          "type": "string"
+        },
+        "username": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "username",
+        "password"
+      ],
+      "type": "object"
+    },
+    "cookies": {
+      "items": {
+        "additionalProperties": false,
+        "properties": {
+          "domain": {
+            "type": "string"
+          },
+          "httpOnly": {
+            "type": "boolean"
+          },
+          "name": {
+            "minLength": 1,
+            "type": "string"
+          },
+          "path": {
+            "type": "string"
+          },
+          "secure": {
+            "type": "boolean"
+          },
+          "value": {
+            "type": "string"
+          }
+        },
+        "required": [
+          "name",
+          "value"
+        ],
+        "type": "object"
+      },
+      "type": "array"
+    },
+    "headers": {
+      "additionalProperties": {
+        "type": "string"
+      },
+      "type": "object"
+    },
+    "userAgent": {
+      "minLength": 1,
+      "type": "string"
+    }
+  },
+  "type": "object"
+}

addedInput schema / properties / selectors

Added value: +{
+  "description": "CSS selectors for the `elements` format.",
+  "items": {
+    "minLength": 1,
+    "type": "string"
+  },
+  "minItems": 1,
+  "type": "array"
+}

changedInput schema / properties / url / description

Previous value: -"Where to start."New value: +"Page to process."

addedInput schema / properties / url / format
```
Added value: +"uri"
```

addedInput schema / properties / viewport

Added value: +{
+  "additionalProperties": false,
+  "description": "The window to render in: `width`, `height`, `deviceScaleFactor`.",
+  "properties": {
+    "deviceScaleFactor": {
+      "maximum": 3,
+      "minimum": 0.1,
+      "type": "number"
+    },
+    "height": {
+      "maximum": 4096,
+      "minimum": 1,
+      "type": "integer"
+    },
+    "width": {
+      "maximum": 4096,
+      "minimum": 1,
+      "type": "integer"
+    }
+  },
+  "required": [
+    "width",
+    "height"
+  ],
+  "type": "object"
+}

addedInput schema / properties / wait

Added value: +{
+  "additionalProperties": false,
+  "description": "When to consider the page loaded: `until` (load, domcontentloaded, networkidle0, networkidle2), `selector` to wait for, `timeout` in ms.",
+  "properties": {
+    "selector": {
+      "minLength": 1,
+      "type": "string"
+    },
+    "timeout": {
+      "maximum": 60000,
+      "minimum": 100,
+      "type": "integer"
+    },
+    "until": {
+      "enum": [
+        "load",
+        "domcontentloaded",
+        "networkidle0",
+        "networkidle2"
+      ],
+      "type": "string"
+    }
+  },
+  "type": "object"
+}

First observedSep 29, 2026

TDQS

A4.3/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations cover only the safety profile (readOnlyHint, destructiveHint, idempotentHint, openWorldHint); the description adds the asynchronous jobId/polling model, credential and credit requirements, and the charge/refund behavior of `limit`, none of which annotations convey. It stops short of failure/retry semantics or rate-limit behavior, so it is strong but not exhaustive.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loads the core action, then job model, billing, and alternatives in four tight sentences; every sentence carries information. The OpenAPI reference link is minor overhead but plausibly useful for a 17-parameter tool.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 17-parameter tool with nested objects and no output schema, the description supplies the essential mental model: async job + status polling, credit cost, and routing to web_map/web_scrape. Return-content detail is implicit via the status tool, which is adequate, though nothing is said about how crawled page results are retrieved or formatted.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents all 17 parameters in detail (including `limit`, `maxDepth`, `formats`, `block`, path filters). The description only restates `limit`'s charging behavior, adding no syntax or format detail beyond the schema. Baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Follows a site's links and reads every page') and immediately differentiates from siblings: 'Use web_map first if you only need the urls' and the web_scrape pointer for screenshots/PDFs. An agent can distinguish this from web_scrape and web_map without opening any schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly names the follow-up tool ('poll it with web_crawl_status'), the alternative for URL-only needs (web_map), and the alternative for screenshot/PDF output (web_scrape). It also flags prerequisites ('API key and credits required'), leaving little to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

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