FREEDOM251

Freedom251 › Developer Tools

Free and open first

Best Tool Calling in 2026

  1. 1

    agentgateway

    Free plan Open source APILinuxMac+3

    agentgateway brings routing, security, observability, and spend controls for model and agent traffic into a self-hosted gateway.

    9.3 Free plan Visit site
  2. 2

    Dify

    Free plan Open source APIExtensionLinux+4

    Dify brings workflow building, knowledge retrieval, model connections, and several publishing options into one platform.

    9.2 Free plan · paid from $59/mo Visit site
  3. 3

    Inngest

    Free plan Open source APILinuxMac+3

    Inngest provides durable execution, observability, and flow controls for asynchronous workflows.

    9.0 Free plan · paid from $99/mo Visit site
  4. 4

    LLM Gateway

    Free plan Open source APIExtensionLinux+2

    LLM Gateway combines provider routing, retry handling, and usage analytics behind one API.

    8.8 Free plan · 30-day trial Visit site
  5. 5

    Rasa

    by Rasa
    Free plan Open source APILinuxMac+3

    Choose Rasa if you need a web platform for building multichannel assistants with visual flows, knowledge-base answers, and human handoff.

    8.7 Free plan · pricing on request Visit site
  6. 6

    Vellum

    Free plan Open source AndroidAPIExtension+5

    Vellum offers a personal assistant with saved context, skills, integrations and approval controls.

    8.5 Free plan · paid from $30/mo Visit site
  7. 7

    Flowise

    Free plan APILinuxMac+3

    Flowise offers visual workflow construction, integrations, and deployment options, but its wind-down is a central consideration.

    7.6 Free plan · paid from $35/mo Visit site
  8. 8

    Liner

    Free plan AndroidAPIExtension+4

    Liner brings cited search, research workflows, and document writing together, with a free plan and paid tiers. Review the upload and agent-credit limits against the work you need to do.

    7.3 Free plan · paid from $14.99/user/mo (annual) Visit site
  9. 9

    Google Cloud API Gateway

    Free plan APIWeb

    Choose Google Cloud API Gateway when you need a managed API layer for supported backends, with authentication, traffic controls, and request monitoring.

    7.2 Free plan · paid from $3 Visit site
  10. 10

    Inference Gateway

    Free plan APILinuxMac+3

    Inference Gateway centralizes provider access, routing, MCP tools, and agent workflows behind one API. It is free, open source, and deployable through Docker, Kubernetes, or self-hosted environments.

    7.2 Free plan Visit site
  11. 11

    Langflow

    Free plan APILinuxMac+3

    Langflow offers visual workflow building alongside Python extensibility, API use, and agent and MCP support. Its execution and isolation model requires care, particularly for multi-tenant deployments.

    7.0 Free plan Visit site
  12. 12

    Gravitee API Management

    Free plan LinuxWebWindows
    6.8 Free plan · paid from $2,500/mo · 14-day trial Visit site
  13. 13

    Pipedream

    by Pipedream
    Free plan APIWeb

    Pipedream brings workflow building, API integrations, and managed authentication into one service.

    6.8 Visit site
  14. 14

    n8n

    by n8n
    Free plan Self-hosted

    Choose n8n if you need flexible workflow automation with code support and a choice of deployment models.

    6.7 Free plan · paid from €20/mo (annual) · 14-day trial Visit site
  15. 15

    Kore.ai

    by Kore.ai
    Free trial APISelf-hostedWeb

    Kore.ai brings agent authoring, workflow automation, deployment, and evaluation into one platform. Pricing requires a request, and the listed trial lasts 14 days.

    6.1 Pricing on request · 14-day trial Visit site
  16. 16

    ToolRoute

    Free plan Web
    5.4 Free plan · paid from $29/mo Visit site
  17. 17

    Amazon Bedrock Data Automation

    by Amazon Web Services
    Paid API

    Amazon Bedrock Data Automation provides structured media processing through an API, with standard and blueprint-defined outputs.

    5.2 From $0.01 Visit site
  18. 18

    Kong AI Gateway

    Paid Web

    Kong AI Gateway combines gateway controls with model and request allowances that vary by plan.

    4.7 30-day trial Visit site
  19. 19

    MCP Gateway

    Paid Web
    4.0 Pricing on request Visit site
  20. 20

    Santeon

    Paid Web
    4.0 Pricing on request Visit site
  21. 21

    Toolhouse

    Paid Web
    3.8 From $500/mo · 14-day trial Visit site

#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price

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