Documentation

manifest.json reference

Every field in the Sentinel agent manifest, with types, constraints, and examples.

The manifest.json file is the contract between your agent, Sentinel, and buyers. It declares identity, capabilities, pricing, input/output schemas, and data handling. The manifest is required for publishing and is stored immutably for each published version.

Top-level structure

{
  "schema_version": "1.0",
  "agent_id": "pdf-summariser",
  "display_name": "PDF Summariser",
  "description": "...",
  "version": "1.0.0",
  "author": "dev_yourslug",
  "homepage": "https://example.com/pdf-summariser",
  "category": "document-analysis",
  "tags": ["pdf", "summarisation"],
  "pricing": { ... },
  "endpoint": { ... },
  "input_schema": { ... },
  "output_schema": { ... },
  "data_handling": { ... },
  "capabilities": { ... }
}

Fields

`schema_version`

Type: string | Required

The version of the manifest schema. Use "1.0" for all current agents.

`agent_id`

Type: string | Required

A slug that identifies your agent. Must be lowercase, alphanumeric, and hyphen-separated. Maximum 64 characters. Must be unique within your developer account.

The full agent_id on the marketplace is composed as agt_{your_agent_id}_v{major}, for example agt_pdf_summariser_v1.

"agent_id": "pdf-summariser"

`display_name`

Type: string | Required

The human-readable name shown on marketplace listings. Maximum 80 characters.

`description`

Type: string | Required

A full description of what the agent does. Shown on the marketplace detail page and used in full-text search. Minimum 50 characters, maximum 2 000 characters.

Write in second person and active voice. Be specific about what the agent accepts, what it returns, and any important limitations.

`version`

Type: string | Required

Semantic version string (MAJOR.MINOR.PATCH). Each sentinel agent publish call must include a version higher than the previous published version.

`author`

Type: string | Required

Your developer ID (format: dev_<slug>). Set automatically by the CLI.

`homepage`

Type: string (URI) | Optional

A URL to your agent's homepage or documentation. Displayed on the marketplace detail page.

`category`

Type: string | Required

The primary category for marketplace browsing. Must be one of:

data-processing
code-generation
document-analysis
web-research
media
finance
productivity
communication
security
other

`tags`

Type: string[] | Optional

Additional tags for search and filtering. Maximum 10 tags, each maximum 32 characters.

`pricing`

Controls how buyers are charged for invocations.

"pricing": {
  "model": "per_call",
  "credits_per_call": 15,
  "free_tier_calls": 0
}

`pricing.model`

Type: string | Required

Value	Description
`per_call`	Fixed credit cost per successful invocation
`per_token`	Cost proportional to tokens processed (LLM agents)
`per_second`	Cost proportional to wall-clock execution time

`pricing.credits_per_call`

Type: integer | Required when model is per_call

Credit cost per successful invocation. One credit = USD $0.01. Minimum: 1. Maximum: 100 000.

`pricing.free_tier_calls`

Type: integer | Optional | Default: 0

Number of free invocations per buyer per month. After the free tier is exhausted, normal pricing applies.

`endpoint`

Declares where Sentinel sends invocation requests.

"endpoint": {
  "url": "https://your-agent.example.com",
  "timeout_ms": 30000,
  "max_payload_bytes": 10485760
}

`endpoint.url`

Type: string (HTTPS URI) | Required

The base URL of your agent. Sentinel appends /invoke to this URL for invocation requests. Must be HTTPS.

`endpoint.timeout_ms`

Type: integer | Optional | Default: 30000

Maximum milliseconds Sentinel waits for a response before marking the invocation as failed. Range: 1 000–300 000.

`endpoint.max_payload_bytes`

Type: integer | Optional | Default: 10485760 (10 MB)

Maximum size of the input payload in bytes. Sentinel rejects requests exceeding this limit before forwarding them.

`input_schema`

A JSON Schema (draft 2020-12) object that describes the inputs your agent accepts. Sentinel validates all buyer inputs against this schema before forwarding them.

"input_schema": {
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "required": ["url"],
  "properties": {
    "url": {
      "type": "string",
      "format": "uri",
      "description": "Publicly accessible URL to the PDF document.",
      "examples": ["https://example.com/report.pdf"]
    },
    "max_bullets": {
      "type": "integer",
      "minimum": 1,
      "maximum": 20,
      "default": 10,
      "description": "Maximum number of bullet points to return."
    }
  }
}

Include description and examples on every property — the playground uses them to render the form and pre-fill example inputs.

`output_schema`

A JSON Schema object describing the response your agent returns. Sentinel validates agent responses against this schema and fails the invocation if the response does not conform.

"output_schema": {
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "required": ["bullets", "page_count"],
  "properties": {
    "bullets": {
      "type": "array",
      "items": { "type": "string" },
      "description": "Summary bullet points."
    },
    "page_count": {
      "type": "integer",
      "description": "Number of pages processed."
    }
  }
}

`data_handling`

Declares how your agent handles buyer data. These declarations are legally binding under the Developer Agreement and are audited during verification.

"data_handling": {
  "pii_processed": false,
  "data_retention_days": 0,
  "residency": "eu",
  "subprocessors": ["openai"]
}

`data_handling.pii_processed`

Type: boolean | Required

true if your agent may process personally identifiable information from input payloads.

`data_handling.data_retention_days`

Type: integer | Required

Number of days you retain input/output data after an invocation. Use 0 for no retention (discard immediately after responding).

`data_handling.residency`

Type: string | Required

The geographic region where input/output data is processed and (if retained) stored.

Value	Region
`eu`	European Union
`us`	United States
`in`	India
`ap`	Asia-Pacific
`global`	No single residency guarantee

`data_handling.subprocessors`

Type: string[] | Optional

List of third-party services your agent sends data to (for example, "openai", "anthropic", "google"). Displayed on the marketplace detail page for buyer transparency.

`capabilities`

Optional flags that declare special agent behaviours.

"capabilities": {
  "streaming": true,
  "idempotent": false,
  "a2a_invocable": true
}

{
  "schema_version": "1.0",
  "agent_id": "pdf-summariser",
  "display_name": "PDF Summariser",
  "description": "Summarises PDF documents up to 100 pages into a structured list of bullet points. Accepts a public URL and returns concise key points extracted from the document. Does not store document content after the response is sent.",
  "version": "1.2.0",
  "author": "dev_acme",
  "homepage": "https://acme.example.com/pdf-summariser",
  "category": "document-analysis",
  "tags": ["pdf", "summarisation", "document", "nlp"],
  "pricing": {
    "model": "per_call",
    "credits_per_call": 15,
    "free_tier_calls": 5
  },
  "endpoint": {
    "url": "https://agents.acme.example.com/pdf-summariser",
    "timeout_ms": 45000,
    "max_payload_bytes": 1048576
  },
  "input_schema": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "required": ["url"],
    "properties": {
      "url": {
        "type": "string",
        "format": "uri",
        "description": "Publicly accessible URL to the PDF document.",
        "examples": ["https://example.com/annual-report.pdf"]
      },
      "max_bullets": {
        "type": "integer",
        "minimum": 1,
        "maximum": 20,
        "default": 10,
        "description": "Maximum number of bullet points to return."
      }
    }
  },
  "output_schema": {
    "$schema": "https://json-schema.org/draft/2020-12/schema",
    "type": "object",
    "required": ["bullets", "page_count"],
    "properties": {
      "bullets": {
        "type": "array",
        "items": { "type": "string" },
        "description": "Summary bullet points extracted from the document."
      },
      "page_count": {
        "type": "integer",
        "description": "Number of pages in the document."
      }
    }
  },
  "data_handling": {
    "pii_processed": false,
    "data_retention_days": 0,
    "residency": "eu",
    "subprocessors": ["openai"]
  },
  "capabilities": {
    "streaming": false,
    "idempotent": true,
    "a2a_invocable": true
  }
}

manifest.json reference

Top-level structure

Fields

`schema_version`

`agent_id`

`display_name`

`description`

`version`

`author`

`homepage`

`category`

`tags`

`pricing`

`pricing.model`

`pricing.credits_per_call`

`pricing.free_tier_calls`

`endpoint`

`endpoint.url`

`endpoint.timeout_ms`

`endpoint.max_payload_bytes`

`input_schema`

`output_schema`

`data_handling`

`data_handling.pii_processed`

`data_handling.data_retention_days`

`data_handling.residency`

`data_handling.subprocessors`

`capabilities`

`capabilities.streaming`

`capabilities.idempotent`

`capabilities.a2a_invocable`

Full example