1) What is Agent API Documentation?

Agent API Documentation is the full set of materials that explains how developers and teams should use an agent API in real applications. Agent APIs often include run-based execution (with run IDs), event streams, tool calling, and optional human approvals for sensitive actions. Therefore, agent API documentation must cover not only endpoints but also workflows, safety boundaries, and operational practices.

In a typical documentation site, you’ll have a mix of guides (“How to integrate”), references (“Endpoint fields”), examples (“Copy/paste code”), and policies (“Data retention and security”). The strongest docs feel like a mini-course: you start with quickstart, then learn advanced patterns, then reference details as needed.

Directory vs documentation

A directory lists many providers; documentation focuses deeply on one API. If you run a directory, you can still use these best practices to standardize listing pages and “docs summaries.”

2) Who Agent API docs serve (and what they need)

Agent API documentation serves multiple audiences. Great docs make each audience feel “seen” by providing the exact information needed for their stage: evaluation, integration, security review, or production operations.

2.1 Key personas

• Developers: want quickstarts, examples, schemas, error codes, limits.
• Engineering leads: want reliability expectations, versioning policy, operational maturity.
• Security & compliance: want permissions, retention, auditability, approvals, data handling details.
• Product managers: want capabilities, constraints, success metrics, and UX guidelines.
• Ops / SRE: want monitoring, incident handling, and scalability guidance.

2.2 Common intents

• “How do I make my first request?”
• “How do I handle async runs?”
• “How do I define tools and validate tool calls?”
• “How do I set budgets and caps to prevent cost spikes?”
• “How do I prove this is safe to my security team?”

3) Recommended structure for Agent API Documentation

A clean structure prevents confusion and makes your docs searchable. Below is an ideal information architecture for agent API docs.

3.1 Minimum pages you should publish

3.2 Navigation principles

• Put Quickstart in the main navigation (always visible).
• Keep Concepts short and visual; move details to reference.
• Use consistent terminology: “run,” “step,” “tool call,” “event.”
• Show “last updated” dates for pages that change (pricing, limits, versioning).

4) Quickstart: first successful agent run

Your quickstart should be the shortest path from “I have a key” to “I got a working result.” It should include: authentication setup, a minimal request, and a clear explanation of the response.

4.1 Quickstart checklist

• How to create an API key or OAuth credentials
• Base URL + environment (sandbox vs production)
• First request (curl + one SDK example)
• How to read the response and extract the output
• Next steps: streaming, tool calling, webhooks

4.2 Generic “first request” example

POST /v1/runs
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json

{
  "task": {
    "type": "research_summary",
    "input": {
      "topic": "Summarize the key risks of deploying AI agents with tool access."
    }
  },
  "constraints": { "max_steps": 8 }
}

Replace /v1/runs, fields, and auth headers based on your provider’s actual specification. Your docs should show exact endpoints.

5) API reference standards (OpenAPI and schema clarity)

The API reference is the “source of truth.” Developers should be able to build directly from it. The best agent APIs provide an OpenAPI specification and keep it updated with versioned changes.

5.1 What your API reference must include

• Endpoint definitions: URLs, methods, request/response schemas
• Auth requirements and scopes
• Pagination and filtering rules (if any)
• Error codes and typical failure modes
• Rate limits, timeouts, and retry guidance

5.2 Schema design tips for agent APIs

• Use strict schemas for structured outputs and tool calls.
• Include enums for states (queued/running/completed/failed).
• Document default values and server-side constraints.
• Mark breaking vs non-breaking changes clearly.

6) Auth documentation: keys, OAuth, and scopes

Auth docs must clarify how to authenticate, how to rotate credentials, and what permissions are possible. Agent APIs often need extra caution because they can trigger actions through tools.

6.1 What to include

• Where keys are created and how to restrict them
• Headers required for each request
• OAuth flows if applicable (auth code, PKCE)
• Scope definitions and examples
• Key rotation and revocation procedures

6.2 Document “least privilege”

Add guidance on separating read-only access from write actions. Encourage approvals for side effects and show how to configure them.

7) Run lifecycle documentation

If your API uses runs, document them as a first-class concept. Runs create state, support async workflows, and enable better monitoring.

7.1 Document run states

7.2 Streaming vs polling

Your docs should specify how to stream run events (SSE/WebSockets) and how to poll for status when streaming is not possible.

8) Tool documentation: schemas, safety, and examples

Tool calling is the most important “agent-specific” documentation. Developers need to define tools, validate requests, and safely execute them. Tool docs should be precise and include strict schemas.

8.1 What tool docs must include

• Tool name and purpose
• Input schema with required fields and validation rules
• Output schema and examples
• Side-effect notes (read-only vs write)
• Policy/approval requirements
• Error modes and retry safety

8.2 Example tool definition (generic template)

{
  "tool": "update_crm_record",
  "description": "Updates a CRM record. Side-effect tool. Requires approval for priority changes.",
  "input_schema": {
    "type": "object",
    "properties": {
      "record_id": {"type":"string"},
      "fields": {
        "type":"object",
        "additionalProperties": {"type":"string"}
      }
    },
    "required":["record_id","fields"],
    "additionalProperties": false
  },
  "output_schema": {
    "type":"object",
    "properties": {
      "ok": {"type":"boolean"},
      "updated_at": {"type":"string"}
    },
    "required":["ok","updated_at"],
    "additionalProperties": false
  }
}

9) Webhooks documentation: async events and verification

Webhooks let you support long-running runs and event-driven workflows. Good webhook docs include a full event catalog, payload examples, and security verification steps.

9.1 What webhook docs should include

• Webhook endpoint registration (dashboard or API)
• Event types (run.completed, run.failed, tool_required, waiting_approval)
• Payload examples for each event
• Signature verification algorithm and headers
• Replay protection guidance (timestamps, event IDs)
• Idempotency guidance (handle duplicates safely)

9.2 Generic webhook payload example

{
  "id": "evt_001",
  "type": "run.completed",
  "created_at": "2026-02-20T10:22:10Z",
  "data": {
    "run_id": "run_abc123",
    "status": "completed",
    "output": {
      "text": "Final response...",
      "structured": {"answer":"...", "citations":[]}
    },
    "usage": {"tokens_in": 1200, "tokens_out": 520}
  }
}

10) Errors and troubleshooting documentation

Errors are inevitable. Your docs should make failures recoverable and help developers avoid the same issues repeatedly. A strong troubleshooting section reduces support workload dramatically.

10.1 What to document

• Error response format (fields like code, message, request_id)
• Common error codes and causes
• Retry guidance: which errors are retryable and with what backoff
• Tool-call failures and how to return structured error results
• Timeouts and cancellation patterns

10.2 Error table (recommended format)

11) Observability documentation: logs, traces, metrics, and cost

If developers can’t debug, they won’t adopt. Observability docs should show how to inspect runs, track tool calls, and understand cost and performance.

11.1 What to document

• Run logs and event history
• Tool call logs (inputs, outputs, timing)
• Tracing/correlation IDs
• Usage metrics (tokens, steps, tool calls)
• Budget controls and caps

12) Changelog & deprecations

Agent APIs evolve quickly. A visible changelog with clear deprecations is essential for trust. Documentation should explain how versions work and how to migrate safely.

12.1 What your changelog should include

• Release date
• New features
• Bug fixes
• Behavior changes
• Deprecations with timelines
• Migration guidance and code examples

12.2 Deprecation policy (recommended)

• Announce breaking changes early
• Keep old versions working for a defined period
• Provide migration guides and warnings in dashboards
• Offer test environments for upcoming versions

13) Copy/paste doc templates (ready sections)

Use these templates to build a documentation site quickly. Replace bracketed sections with your specific details.

13.1 Quickstart template

# Quickstart

## 1) Create an API key
- Go to: [Dashboard path]
- Click: [Create key]
- Copy the key and store it safely.

## 2) Make your first request (curl)
```bash
curl -X POST "[BASE_URL]/v1/runs" \
  -H "Authorization: Bearer $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{ ... }'
  { ... }

{ ... }

15) Documentation quality checklist

Use this checklist to verify your documentation is complete, accurate, and production-friendly. Many docs look good but fail because examples don’t work or safety constraints are unclear.

Safety section (recommended to include prominently)

Agent APIs are powerful because they can take actions through tools, but that also increases risk. Documentation should include a dedicated safety section, even if you also repeat safety notes elsewhere.

Safety best practices to document

• Least privilege: separate read and write tools; scope data access.
• Approvals: require human review for sensitive actions.
• Validation: strict schema validation for every tool call.
• Budgets: caps on steps/tokens/tool calls to avoid loops and cost spikes.
• Auditability: log tool calls, approvals, and run timelines.

FAQs (100+)

These FAQs are designed for long-tail search and support deflection. Keep answers short, and link to the correct section.

Basics (1–15)

More FAQs (16–110)

Grouped by topic. Expand as needed for your website.

Disclaimer

This page is educational and outlines general best practices for Agent API Documentation. It is not legal, security, or compliance advice. Always validate details with your provider’s official specifications and policies.