Developer Tools·Standings

Compare Tool Calling Software

Tool-calling tools let apps connect to external services and carry out requested actions; compare protocol support and control over which tools a model can call.

This board uses a signal score out of 10. The API, open-source and free-tier marks help you see how a tool can be accessed, inspected or tried.

• 21 platforms
• 15 with a free tier
• Checked 7 Oct 2026

1. #PlatformSignalPlugs inPrice
2. 1
   V

   Vellumvellum.ai

   A personal AI assistant can manage files, calendars, email, code, and computer controls; free plan.

   7.7 APIOpenFree Free tier · from $30/mo
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3. 2
   I

   Inngestinngest.com

   A workflow service runs background tasks and agents with automatic retries and recovery; free plan.

   7.7 APIOpenFree Free tier · from $99/mo
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4. 3
   R

   Rasarasa.com

   An open-source platform for building conversational AI; free plan available.

   7.7 APIOpenFree Free tier
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5. 4
   D

   Difydify.ai

   An open-source visual builder creates AI apps with models, tools, and knowledge retrieval; free plan.

   7.7 APIOpenFree Free tier · from $590/yr
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6. 5
   A

   agentgatewayagentgateway.dev

   An open-source gateway routes and secures AI, service, and tool traffic; free to self-host.

   7.7 APIOpenFree Free tier
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7. 6
   LG

   LLM Gatewayllmgateway.io

   An open-source gateway routes requests across 250+ models; its free plan includes usage analytics.

   7.4 APIOpenFree Free tier
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8. 7
   L

   Linerliner.com

   An AI search and research app offers cited answers and tools for finding and comparing papers.

   6.7 APIOpenFree Free tier · from $14.99/mo
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9. 8
   L

   Langflowlangflow.org

   A free, open-source visual builder connects AI tools and models, including Slack and Google Drive.

   6.4 APIOpenFree Free tier
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10. 9
    IG

    Inference Gatewaydocs.inference-gateway.com

    A free, open-source gateway connects hosted and local AI models through one API.

    6.3 APIOpenFree Free tier
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11. 10
    F

    Flowiseflowiseai.com

    An open-source visual builder creates AI agents and workflows; its service is set to end in 2026.

    6.2 APIOpenFree Free tier · from $35/mo
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12. 11
    N

    n8nn8n.io

    A self-hosted workflow tool connects services in multi-step automations; free plan available.

    6.1 APIOpenFree Free tier · from €20/mo
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13. 12
    GC

    Google Cloud API Gatewaycloud.google.com

    A Google Cloud service secures and monitors backend services through REST APIs; free plan.

    6.0 APIOpenFree Free tier · from $1.50/mo
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14. 13
    P

    Pipedreampipedream.com

    Pipedream describes itself as an integration layer for AI agents, providing managed authentication and tools across thousands of APIs.

    5.8 APIOpenFree Free tier · from $99/mo
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15. 14
    KA

    Kore.aikore.ai

    Assistant software that can be deployed across multiple channels.

    5.6 APIOpenFree —
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16. 15
    GA

    Gravitee API Managementgravitee.io

    API software for managing access, with a portal, catalog, and free option.

    5.5 APIOpenFree Free tier · from $2,500/mo
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17. 16
    T

    ToolRoutetoolroute.ai
    4.8 APIOpenFree Free tier
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18. 17
    KA

    Kong AI Gatewaykonghq.com
    4.4 APIOpenFree —
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19. 18
    AB

    Amazon Bedrock Data AutomationAmazon Web Services

    A cloud service extracts and standardizes information from documents, images, video, and audio.

    4.3 APIOpenFree From $0.01/mo
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20. 19
    S

    Santeonsanteon.ai
    4.0 APIOpenFree —
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21. 20
    MG

    MCP Gatewaymcpgateway.com

    A self-hosted MCP gateway provides structured outputs, authentication, and call monitoring.

    4.0 APIOpenFree —
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22. 21
    T

    Toolhousetoolhouse.ai

    A cloud MCP service provides call monitoring, with plans from $500 a month.

    4.0 APIOpenFree —
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Places #1, #2, #3, #4, #5 on this board are open to sponsors. Take #1 · Other ways to advertise

How to choose

Which protocols does it need to support?

Choose a tool that supports the protocols your apps use to make tool calls. Protocol support is one of the comparison points on this board.

Where do I need to run it?

Check the deployment options against your setup. The board includes web, API and self-hosted options, as well as Windows, macOS and Linux availability.

How much control do I need over tool calls?

Compare tool-choice control and parallel tool calls. These settings help determine how a model selects tools and whether it can call more than one at once.

What output and monitoring features should I compare?

Structured outputs can make tool-call results easier for an app to handle. Call observability helps you see information about calls; compare it alongside authentication methods.

How can I compare free plans and paid costs?

Check whether a free plan is available and what the paid starting price is. A free trial is a separate offer, so look for it separately when comparing options.

Questions

What is tool calling?

Tool calling lets an app connect a model to external tools so it can request actions or information through them.

What should I compare when choosing a tool-calling platform?

Compare protocol support, deployment, tool-choice control, parallel calls, structured outputs, authentication methods and call observability.

Can I run tool-calling software on my own server?

Self-hosted is one deployment option shown on the board. Check the individual tool's deployment details to confirm it fits your setup.

How do I know if a tool-calling platform has a free plan?

Check the free-plan mark and the tool's pricing details. A free plan and a free trial are different offers.

What does tool-choice control mean?

It describes how much control you have over which tool a model calls. Compare this setting if your app needs to guide or restrict tool selection.

Some top positions on this board can be paid placements, standing where they were sold. The facts on each platform are not for sale. How we rank · Disclosure