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  "title": "Charter",
  "description": "Charter is a Python library that lets you declare agent API tools as Pydantic schemas instead of hand-implementing them, auto-handling request construction, auth, wire format, and response trimming. Open source: yes (Apache-2.0); self-hostable; pricing free. In-process, no telemetry; launched 2026-09-28; 1 star.",
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  "open_source": "yes",
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  "who_its_for": "A Python engineer wiring an agent to real APIs who would rather declare each tool once as a Pydantic schema — letting the library build the request, handle auth and wire format, and trim the response — than hand-implement a stack of bespoke tool functions.",
  "who_its_not_for": "Non-Python stacks, or teams that need a mature, widely-adopted framework rather than a day-one library at 1 star.",
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    "note": "Apache-2.0 per repo; 1 star; launched 2026-09-28; Python library, runs in-process, no telemetry; tools declared as Pydantic schemas with auto request construction, auth, wire format and response trimming. Vendor-reported across 534 runs: malformed GraphQL 32->0, unauthorized endpoint calls 10->0, and ~1/4 the bytes forwarded vs raw HTTP tools (7,382 vs 36,383 bytes/run) (github.com/r28ai/charter, verified 2026-09-28)."
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  "caveats": "Verified from the primary repo (2026-09-28); no independent testing here. The 534-run figures — malformed GraphQL 32->0, unauthorized calls 10->0, ~4x fewer forwarded bytes (7,382 vs 36,383) — are the maker's own measurement (vendor-claim), not independently reproduced. This is a day-one release at 1 star: a promising declarative pattern, not a proven, hardened framework.",
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      "text": "Charter is a Python library that lets you declare agent API tools as Pydantic schemas instead of hand-implementing them, auto-handling request construction, auth, wire format, and response trimming. Open source: yes (Apache-2.0); self-hostable; pricing free. It runs in-process with no telemetry, launched 2026-09-28, and has 1 star."
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      "text": "Charter is a Python library that lets you declare agent API tools as Pydantic schemas instead of hand-implementing them, auto-handling request construction, auth, wire format, and response trimming. Open source: yes (Apache-2.0); self-hostable; pricing free. It runs in-process with no telemetry, launched 2026-09-28, and has 1 star.\n\nCharter replaces the usual pile of hand-written tool functions with a declaration. You describe each API tool once as a Pydantic schema, and Charter does the plumbing: it constructs the request, handles authentication, deals with the wire format, and trims the response down before it reaches the model — so the agent both calls the API correctly and does not drown in raw payload. It is a plain Python library that runs in-process, with no telemetry phoning home. Open source: yes (Apache-2.0); self-hostable; pricing free."
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      "text": "the wire format, and trims the response down before it reaches the model — so the agent both calls the API correctly and does not drown in raw payload. It is a plain Python library that runs in-process, with no telemetry phoning home. Open source: yes (Apache-2.0); self-hostable; pricing free.\n\n- Apache-2.0 per repo; 1 star; launched 2026-09-28; Python library, in-process, no telemetry; tools declared as Pydantic schemas with auto request construction, auth, wire format and response trimming (github.com/r28ai/charter, verified 2026-09-28).\n- Maker-reported over 534 runs: malformed GraphQL calls dropped 32->0, unauthorized endpoint calls 10->0, and forwarded bytes fell to ~1/4 of raw HTTP tools (7,382 vs 36,383 bytes/run). Stated here as the maker's own numbers (vendor-claim), not independently reproduced.\n- Curated from the GTM Stacker signal registry (2026-09-28 pass); license/facts independently verified 2026-09-28."
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      "text": "534 runs: malformed GraphQL calls dropped 32->0, unauthorized endpoint calls 10->0, and forwarded bytes fell to ~1/4 of raw HTTP tools (7,382 vs 36,383 bytes/run). Stated here as the maker's own numbers (vendor-claim), not independently reproduced. - Curated from the GTM Stacker signal registry (2026-09-28 pass); license/facts independently verified 2026-09-28.\n\nA GTM agent's usefulness is mostly its tools — CRM writes, enrichment lookups, GraphQL queries — and each hand-built tool is code to get right and bytes of response to feed the model on every call. Charter attacks both: declare the tool as a schema and let the library enforce correct, authorized requests and trim the response, which directly cuts malformed calls and token spend. Open source: yes (Apache-2.0); self-hostable; pricing free. The honest read: the declarative-tool idea is sound and the maker's 534-run numbers (fewer malformed/unauthorized calls, ~4x fewer forwarded bytes) point the right way, but this is a Python-only, day-one project at 1 star — trial it on one integration and confirm the lift before standardizing your tool layer on it."
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